Preflight Weather Analysis Lesson 4 Part 4 of 4

Preflight Weather Analysis Lesson 4 Part 4 of 4 Presented by Find-it Fast Books Unlimited FREE Downloads of this course available at www.finditfastbooks.org 1

The slide sequence for Lesson 4 is a little different than the previous lessons. Each slide presented for your review is followed by a subsequent slide offering more explanation or a brief discussion. 2

METAR and SPECI Current Conditions Partial Obscurations Sky Partially Obscured by a Ground Based Phenomenon Amount of Obscuration: FEW SCT BKN Followed by Three Zeros -- 000 Reference: Page 28 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 3

Obscurations are reported when the sky is partially obscured by a ground based phenomenon by indicating the amount of obscuration as FEW, SCT, or BKN followed by three zeros (000) in the body of the METAR. A METAR makes no distinction between a partial obscuration and a cloud layer in the body of a report. The METAR encodes the obscuration as a cloud layer whose base is below 50 feet. REMARKS will report the type of obscuration. 4

METAR and SPECI Current Conditions Partial Obscurations FEW000 Greater Than 0 to 2/8 of the Sky is Obscured) KSFO 021054Z 00000KT 4SM BR FEW000 22/21 A2995 RMK BR FEW000 Spoken as: Few clouds less than five zero (feet) (in Remarks) Mist obscuring up to two-eighths of the sky Reference: Page 28 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 5

Here are the obscuration values for FEW -- Zero to two-eighths of the sky obscured. The example on the slide highlights the partial obscuration value in the body of the METAR in red. Notice that REMARKS reports the type of obscuration as, in the example on the previous page, Mist (BR), also highlighted in red. 6

METAR and SPECI Current Conditions Partial Obscurations SCT000 Greater Than 3/8 to 4/8 of the Sky is Obscured KSFO 021054Z 00000KT 4SM BR SCT000 22/21 A2995 RMK BR SCT000 Spoken as: Scattered clouds less than five zero (feet) (in Remarks) Mist obscuring three to four-eighths of the sky Reference: Page 28 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 7

The previous slide shows the obscuration values for Scattered (SCT): Three-eighths to four-eighths of the sky obscured. The example on the previous slide highlights the partial obscuration value in the body of the METAR in red. Notice that REMARKS reports the type of obscuration as, in the example on the previous page, also Mist (BR), highlighted in red. 8

METAR and SPECI Current Conditions Partial Obscurations BKN000 Between 5/8 and 7/8 of the Sky is Obscured KSFO 021054Z 00000KT 1/2SM FG BKN000 22/21 A2995 RMK FG BKN000 Spoken as: Broken clouds less than five zero (feet) (in Remarks) Fog obscuring five to seven-eighths of the sky Reference: Page 28 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 9

The previous slide shows the obscuration values for Broken (BKN): Five-eighths to seven-eighths of the sky obscured. The example on the slide highlights the partial obscuration value in the body of the METAR in red. Notice that REMARKS reports the type of obscuration as, in the example on the previous page, Fog (FG), also highlighted in red. 10

METAR and SPECI Current Conditions Sky Condition METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLPNO T0011032 VV008 -- Spoken as Indefinite Ceiling 800 (feet) VV = Vertical Visibility -- Surface Based A Complete Obscuration -- Total Sky Coverage Reference: Page 29 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 11

VV stands for vertical visibility. When you see VV, a surface based phenomena is occurring. As opposed to the partial obscuration covered on the previous slides, vertical visibility refers to a total, full obscuration -- Total sky coverage is 100 percent. If surface-based obscurations like fog, smoke, haze are reported, and the lowest broken or overcast cloud base cannot be determined, then vertical visibility in hundreds of feet determines the ceiling. 12

METAR and SPECI Current Conditions Sky Condition Sky Cover is Reported in EIGHTHS of Coverage Using the Below Contractions: AGL Reportable Summation Contractions Meaning Amount VV Indefinite Ceiling 8/8 (vertical visibility) SKC or CLR Clear 0 or 0 below 12,000 FEW Few > 0 but < 2/8 SCT Scattered 3/8 to 4/8 BKN Broken 5/8 to 7/8 OVC Overcast 8/8 CB Cumulonimbus When present TCU Towering Cumulus When present Reference: Page 29 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 13

Sky Cover is Reported in eighths of Coverage. The sky cover summation amount for a given layer of clouds is the sum of the sky cover of all lower cloud layers plus the layer evaluated, all added together. A ceiling is determined by the first broken (BKN) or Overcast (OVC) layer. All cloud layers are considered opaque. There are no Thin cloud layers in METARs. METAR stations report cloud layers above the surface, in other words, above ground level (AGL). 14

METAR and SPECI Current Conditions Sky Condition SKC or CLR = Clear or Clear below 12,000 CLR Used at Automated Stations No Layers at or Below 12,000 Feet SKC Used at Manual Stations When No Cloud Layers Reported Reference: Page 29 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 15

The abbreviation CLR is used at automated stations when no layers at or below 12,000 feet are reported. Automated stations do not report clouds above 12,000 feet. So, if a METAR reports clear below 12,000 (CLR), cloud layers may exist above 12,000 feet. The abbreviation SKC is used at manual stations when no cloud layers are reported. 16

METAR and SPECI Current Conditions Sky Condition CB = Cumulonimbus (Thunderstorm) TCU = Towering Cumulus (Developing Thunderstorm) Appended to Associated Cloud Layer Example: SCT015TCU Reference: Pages 29-31 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 17

Cumulonimbus (CB) or towering cumulus (TCU) coding is appended to the associated layer of reported clouds. For example, a scattered layer of towering cumulus at 1,500 feet would be coded SCT015TCU and would be followed by a space, then any additional higher cloud layers. CB and TCU are considered significant clouds due to the flight hazard of severe turbulence, among others, associated with them. 18

METAR and SPECI Current Conditions Sky Condition Additional CB or TCU Data In REMARKS: Distance (If Known) Direction From Station - or If Overhead (OHD) Direction of Movement (If Known) DSNT (Distant) - Clouds Beyond 10 Miles From Airport Reference: Pages 29-31 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 19

Additional information about the CB or TCU will be reported in the REMARKs element of a METAR: 20

METAR and SPECI Current Conditions Sky Condition CBMAM -- Cumulonimbus Mammatus ACC -- Altocumulus Castellanus ACSL -- Standing Lenticular Altocumulus CCSL -- Standing Lenticular Cirrocumulus ROTOR CLOUD Reference: Page 30 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 21

There are other significant cloud types that are more rarely seen which are thunderstorm or severe turbulence fight hazards, as well: CBMAM - Thunderstorm and severe turbulence. ACC - Severe turbulence ACSL - Severe turbulence Rotor Cloud - Violent, rotating severe turbulence. A Rotor cloud is a horizontally aligned cloud formation preceding the most severe thunderstorms. 22

METAR and SPECI Current Conditions Sky Condition Examples of Significant Clouds in REMARKS: CB N MOV E Cumulonimbus North Moving East CBMAM DSNT W Cumulonimbus Mammatus Distant West ACC NE - E Altocumulus Castellanus Northeast Through East APRNT ROTOR CLD W Apparent Rotor Cloud West Reference: Page 30 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 23

As you can see, distance, direction, and direction of movement are reported in the remarks, on the previous slide, to aid a pilot in determining the location of these hazardous clouds and their relationship to the reporting station. 24

METAR and SPECI Current Conditions Sky Condition Variable Ceiling Below 3,000 Feet -- CIG in REMARKS Followed by Lowest and Highest Ceiling Heights Separated by a V Example: CIG 006V012 Reference: Page 31 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 25

Whenever a ceiling below 3,000 feet is reported and it is variable, CIG will be shown in remarks followed by the lowest and highest ceiling heights separated by a V. Example: CIG 006V012 Ceiling variable between six hundred and one thousand two hundred 26

METAR and SPECI Current Conditions Sky Condition Variable Sky Cover -- in REMARKS Separated by a V Examples: SCT V BKN BKN V OVC Reference: Page 31 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 27

When a layer of clouds varies in sky cover, the variability range is shown in remarks, separated by a V. Example: BKN V OVC Broken layer variable to overcast. 28

METAR and SPECI Current Conditions Sky Condition Reporting Station in Mountains: If Cloud Layer BELOW Station Height Cloud Layer Base = Three Slashes Example: /// Reference: Pages 29-31 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 29

At weather reporting stations located in the mountains, if a cloud layer is reported that is below the station level height, the height will be shown as three slashes: /// 30

METAR and SPECI Current Conditions Temperature / Dew Point METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLPNO T0011032 Two Digits Separated by Slash Celsius M = Minus (Below Zero) Reference: Page 33 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 31

Temperature and dew point are reported in two digits each in whole degrees CELSIUS, separated by a slant ( / ). In this example: 00/M03 is spoken as Temperature zero, dew point minus three. Temperatures and dew points below zero are preceded with an M for Minus. 32

METAR and SPECI Current Conditions Temperature / Dew Point METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/ A2991 RMK A02 RAESNB42 SLPNO T0011032 If Temperature Available But Dew Point Missing Temperature Followed by a Slant Reference: Page 33 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 33

If the temperature is available but the dew point is missing, the temperature is shown followed by a slant ( / ). 34

METAR and SPECI Current Conditions Temperature / Dew Point METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 A2991 RMK A02 RAESNB42 SLPNO T0011032 If Temperature Missing Entire Group Omitted From METAR Reference: Page 33 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 35

If the temperature is missing, the entire group is omitted from the METAR. 36

METAR and SPECI Current Conditions Altimeter METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLPNO T0011032 4 Digit Barometric Pressure Reading Preceded with A No Decimal Point A2991 Altimeter Two Niner-Niner One Reference: Page 34 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 37

The altimeter setting is reported in four digits representing tens, units, tenths, and hundredths of inches of mercury -- the barometric pressure. The decimal is not noted or stated. It is preceded with an A. An altimeter setting of 29.92 inches of mercury would be depicted as: A2991 Altimeter two niner-niner one. 38

METAR and SPECI Current Conditions Altimeter METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK PRESRR PRESRR = Pressure Rising Rapidly PRESFR = Pressure Falling Rapidly Pressure Change of 0.06 Inch Per Hour Pressure Change of 0.02 Inch During Observation Reference: Page 34 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 39

When barometric pressure is rising or falling at a rate of at least 0.06 inches per hour and the pressure change totals 0.02 inches or more at the time of the observation, REMARKs will show PRESRR or PRESFR, respectively. These rapid pressure changes sometimes occur during strong thunderstorm activity, or during strong, fast moving frontal passages. 40

METAR and SPECI Current Conditions Remarks METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLPNO T0011032 $ 2 Major Groups Automated -- Manual -- Plain Language Additive and Maintenance Data Maintenance Indicator -- $ Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 41

Remarks are broken into two major groups: (1) Automated, Manual, and Plain Language followed by: (2) Additive and Maintenance Data. A maintenance indicator sign, $, is appended to the end of an automated weather report when the unit detects that maintenance is needed on the system The METAR, itself, is valid, but you may notice an element missing due to the maintenance issue. 42

METAR and SPECI Current Conditions Remarks METAR KSEA 141545Z 33018KT 2SM SN 00/M03 A2991 RMK RAESNB42 Time Entries: Same Hour -- 2 Digits -- Minutes Past the Hour Different Hour -- 4 Digits -- Hours and Minutes RAESNB42 = Rain Ended, Snow Began at :42 Past the Hour Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 43

Time entries are made in minutes past the hour if the time reported occurs during the same hour the observation is taken. Hours and minutes are used if the hour is different. Again, note the example on the previous slide : Rain ended and snow began at :42 past the hour. 44

METAR and SPECI Current Conditions Remarks KTPA 260053Z 00000KT 10SM TS BKN020 OVC040 26/23 A2991 RMK TS MOV NE Movement: Direction Weather Moving Toward Clockwise 8 Point Compass Directions TS MOV NE = Thunderstorm Moving Northeast Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 45

Movement of clouds or weather, if known, is coded with respect to the direction toward which the phenomena is moving. Directions use the eight points of the compass coded in clockwise order. For example, a thunderstorm moving toward the northeast would be coded as TS MOV NE. 46

METAR and SPECI Current Conditions Remarks METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLP982 T0011032 $ Sea Level Pressure -- SLP (Millibars) Example: SLP982 Do Not Confuse SLP with Altimeter Setting If SLP Not Available = SLPNO Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 47

At some designated stations, the sea-level pressure is shown in remarks where SLP is followed by the sea-level pressure in millibars. Non-U.S. international pilots may use sea level pressure as opposed to the altimeter setting. Do not confuse SLP with the altimeter setting. If sea-level pressure is not available, it will be shown as SLPNO. 48

METAR and SPECI Current Conditions Remarks METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLPNO T0011032 AUTO in Report Body = No Human Intervention A01 = NO Precipitation Discriminator A02 = CAN Determine Type of Precipitation Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 49

The word AUTO in the body of a METAR identifies an automated weather report with no human intervention. A01 or A02 will be in REMARKS with automated reports. A01 means NO precipitation discriminator. A02 means a precipitation discriminator can determine type of precipitation. 50

METAR and SPECI Current Conditions Remarks METAR KSEA 141545Z AUTO 33018KT 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLPNO T0011032 TSNO A METAR Trap! TSNO Does NOT Mean No Thunderstorms TSNO Means Thunderstorm Information IS NOT AVAILABLE Reference: Page 35 - Preflight Weather Analysis Made Easy, by Find-it Fast Books, website www.finditfastbooks.org 51

A METAR Trap: In the remarks section of a METAR, you may see the term TSNO. This remark does NOT mean there are no thunderstorms. TSNO means thunderstorm information is not available. Thunderstorms occurring at this METAR location would not be reported. If conditions are favorable for thunderstorm development, be sure to check other resources. 52

METAR and SPECI Current Conditions Remarks MT. HOOD VOLCANO 50 MILES W ERUPTED 161410 LARGE ASH CLOUD EXTENDING TO APPROX 40000 FEET MOVING E Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 53

The number of remarks for METARs is extremely large. Some REMARK entries were explained in earlier slides. In the remaining slides, we will take a look at some other important and common remarks you are likely to encounter in METARs. We ll begin this series with the seldom seen, but most important remark of all, Volcanic Eruptions, as shown on the previous slide. No coding is used in this remark. It is entirely written out in plain text for clarity. 54

METAR and SPECI Current Conditions Remarks Tornado -- Funnel Cloud -- Waterspout: (In METAR Body) FC = Funnel Cloud (In METAR Body) +FC = Tornado or Waterspout Example: TORNADO B15 DSNT SE Tornado Began at 15 Past the Hour, to the Distant Southeast Reported by Manual Stations Only Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 55

Tornadoes, Funnel Clouds, and Waterspouts are reported at manual stations only. The body of the METAR will report the tornado, funnel cloud or waterspout, and in REMARKs, additional information will indicate beginning time, location, distance, movement, and ending time, if known. Example: TORNADO B15 DSNT SE Tornado began one five past the hour to the distant Southeast. 56

METAR and SPECI Current Conditions Remarks Peak Wind: In REMARKs When Exceeds 25 Knots Example: PK WND 25035/1825 Peak wind two five zero at three five occurred at one eight two five Example: PK WND 32040/26 Peak wind three two zero at four zero occurred at two six past the hour Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 57

Peak Wind (PK WND) - Whenever the peak wind exceeds 25 knots, PK WND will be included in remarks. Example: PK WND 25035/1825 Peak wind two five zero at three five occurred at one eight two five. Example: PK WND 32040/26 Peak wind three two zero at four zero occurred at two six past the hour. 58

METAR and SPECI Current Conditions Remarks Lightning: Frequency Type Location Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 59

Lightning (LTG) When lightning is seen by the weather observer, it will be included in remarks. The frequency of occurrence, type of lightning when observed, and the location will be indicated. The location is determined in reference to the point of observation. 60

METAR and SPECI Current Conditions Remarks Frequency of Lightning: OCNL -- Occasional -- Less Than 1 Flash Per Minute FRQ -- Frequent -- About 1 to 6 Flashes Per Minute CONS -- Continuous -- More Than 6 Flashes Per Minute Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 61

The frequency of lightning is based on flashes per minute, as shown on the previous slide: OCNL Occasional (less than 1 flash per minute) FRQ Frequent (about 1 to 6 flashes per minute) CONS Continuous (more than 6 flashes per minute) 62

METAR and SPECI Current Conditions Remarks Types of Lightning: CG -- Cloud to Ground IC -- In Cloud CC -- Cloud to Cloud CA -- Cloud to Air Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 63

Again, as shown on the previous slide: Types of Lightning include: CG Cloud to ground IC In cloud CC Cloud to cloud CA Cloud to air 64

METAR and SPECI Current Conditions Remarks Examples of Lightning in REMARKS: FRQ LTG VC Frequent Lightning in the Vicinity of the Station CONS LTGCC NE Continuous Lightning Cloud to Cloud, Northeast LTG DSNT S Lightning Distant South Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 65

The previous slide shows some examples of lightning common in METAR REMARKs you will see during reported thunderstorms, repeated here: FRQ LTG VC Frequent lightning in the vicinity of the station CONS LTGCC NE Continuous lightning cloud to cloud, Northeast LTG DSNT S Lightning distant South 66

METAR and SPECI Current Conditions Remarks Begin / End Times of Precipitation: Type of Precipitation Reported With Beginning and / or End Times Not Required in SPECI Reports Shown in Next METAR Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 67

When precipitation begins or ends, REMARKS will show the type of precipitation as well as the beginning and/or ending time(s) of occurrence. Intensity is not shown. Only the minutes are required if the hour can be inferred from the report time. Types of precipitation may be combined if beginning or ending times are the same. These remarks are not required in SPECI reports but will be shown in the next METAR. 68

METAR and SPECI Current Conditions Remarks Begin / End Times of Precipitation: Type of Precipitation Reported With Beginning and / or End Times Example: RAB05E30SNB20E55 Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 69

The previous slide is an example of precipitation beginning and ending times: RAB05E30SNB20E55 This is spoken as: Rain began at zero five, ended at three zero, snow began at two zero, ended at five five. 70

METAR and SPECI Current Conditions Remarks Begin / End Times of Thunderstorms Thunderstorm Reported With Beginning and / or End Times Required in SPECI Reports Shown in Next METAR Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 71

When thunderstorms begin or end, REMARKS will show the thunderstorm as well as the beginning and/or ending time(s) of occurrence. Only minutes will be shown if the hour can be inferred from the time of the weather report. These remarks are required in SPECIs and will also be shown in the next METAR. 72

METAR and SPECI Current Conditions Remarks Begin / End Times of Thunderstorms Thunderstorm Reported With Beginning and / or End Times Example: TSB05E40 Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 73

The previous slide is an example of thunderstorm beginning and ending times: TSB05E40 This is spoken as: Thunderstorm began at zero five, ended at four zero. 74

METAR and SPECI Current Conditions Remarks Examples of Thunderstorms in REMARKS: TS OHD MOV E Thunderstorm overhead, moving east TS VC NE MOV E Thunderstorm in the vicinity northeast, moving east TS DSNT N MOV SE Thunderstorm distant north, moving southeast Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 75

The previous slide shows some examples of thunderstorm REMARKs you will see during reported thunderstorms: TS OHD MOV E Thunderstorm overhead, moving east. TS VC NE MOV E Thunderstorm in the vicinity northeast, moving east. TS DSNT N MOV SE Thunderstorm distant north, moving southeast. 76

METAR and SPECI Current Conditions Remarks Hailstones: GR = Large Hail Two-Tenths Inch or Greater GS = Small Hail or Snow Pellets -- Not Reported in REMARKs Example of Large Hailstones in REMARKs: GR 3/4 Hailstones Three Quarter Inch in Diameter Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 77

The METAR reporting code for large hail twotenths of an inch or greater in diameter is GR, while smaller hailstones are coded GS. The size of the largest hailstones, in 1/4 inch increments, is shown in remarks preceded with the contraction for hail, GR. If small hail or snow pellets (GS) are encoded in the body of the report, no remark will be shown in reference to size. Example: GR 3/4 Hailstones three quarter inch in diameter 78

METAR and SPECI Current Conditions Remarks VIRGA: Precipitation Not Reaching the Ground Examples of VIRGA in REMARKS: VIRGA Virga at the Station VIRGA DSNT SE Virga Distant Southeast Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 79

When precipitation is observed but is not reaching the ground, VIRGA is shown in remarks. The direction from the station may also be reported. Examples: VIRGA Virga at the station VIRGA DSNT SE Virga distant Southeast 80

METAR and SPECI Current Conditions Remarks 2nd Site Ceiling: At Automated Stations Cloud Height at Second Location Example: CIG 010 RY22 Ceiling One Thousand at Runway Two-Two Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 81

Sky @ 2nd Site (Ceiling) Some automated weather reporting stations may show site specific cloud heights at a secondary location in remarks. The remark format is CIG (cloud height) (location). Example: CIG 010 RY22 Ceiling one thousand at runway two two 82

METAR and SPECI Current Conditions Remarks ADDITIVE and AUTOMATED MAINTENANCE DATA: METAR KSEA 141545Z AUTO 33018KT 290V360 1/2SM R31/2600FT +SN BLSN FG VV008 00/M03 A2991 RMK A02 RAESNB42 SLPNO T0011032 Additive Data Used by Meteorologists Additive Data Some Maintenance Data Significant to Pilots Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 83

Additive data groups are reported at designated weather reporting stations. Most remarks in this category are not operationally significant for aviation purposes and are used by meteorologists. The maintenance data groups are only reported from automated weather reporting stations. The next slides show a few remarks that have significance to you by indicating the unavailability of certain weather sensors. 84

METAR and SPECI Current Conditions Remarks Operationally Significant Maintenance Indicators: TSNO -- Thunderstorm information not available FZRANO -- Freezing rain information not available RVRNO -- Runway visual range information not available NOSPECI -- No special weather reports Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 85

If an automated weather reporting station is equipped with thunderstorm or freezing rain sensors and they are not working, remarks will indicate this information is not available. If the runway visual range (RVR) element in the body of the weather report should be reported but is missing, RVRNO will be in remarks. At manual weather observing stations that do not take special weather reports, NOSPECI is shown in remarks of all METAR reports. 86

METAR and SPECI Current Conditions Remarks Operationally Significant Maintenance Indicators: VISNO -- Visibility sensor information not available CHINO -- Sky condition at secondary location not available PWINO -- Present weather identifier not available PNO -- Precipitation amount not available Reference: Pages 35-44 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 87

On the previous slide are some additional maintenance indicator remarks that have significance to you by indicating the unavailability of certain weather sensors. For example, if the visibility sensor not working, VISNO will be shown in remarks. If you find some reporting elements in the body of a METAR omitted, REMARKs entries may explain why. 88

PILOT REPORT (PIREP) Are There Any Pilot Reports Near My Route of Flight? Routine Pilot Report (UA) SGF UA/ OV SGF040020 /TM 1550 /FL030 /TP C210 /SK OVC027-TOP060 /TA M08 /TB LGT-MDT CHOP /IC LGT-MOD MX /RM IC 027-060 Urgent Pilot Report (UUA) SGF UUA/ OV SGF040020 /TM 1550 /FL030 /TP C210 /SK OVC037-TOP060 /TA M08 /TB LGT-MDT CHOP /IC SEV MX /RM IC 037-060 Reference: Page 37 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 89

A pilot report, or PIREP, is a report of actual weather conditions encountered by an aircraft in flight. This information is usually relayed by radio to the nearest flight service station or ATC facility (Tower or Center). There are two types of Pilot Reports. The Routine Pilot Report is designated by UA. The Urgent Pilot Report is identified by the three letters UUA. Flight Service specialists solicit Pilot Reports from pilots to encourage more frequent reports of inflight conditions. Pilot Reports are an excellent source of enroute weather conditions between weather reporting locations. 90

PILOT REPORT (PIREP) Actual Inflight Weather Conditions Reported Disseminated as Soon as Reported Coordinated Universal Time Nautical Miles Celsius Temperatures True North Wind Vectors Reference: Page 37 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 91

PIREPs are a supplementary resource for in flight weather conditions that verify forecasts and supplement the METARs while filling in the gaps between ground reporting stations. They are disseminated as soon as received, using Coordinated Universal Time. Distances are in nautical miles. Temperatures in Celsius. And all winds are reported from TRUE north. 92

PILOT REPORT (PIREP) Reporting Elements /OV Over /TM Time (UTC) /FL Altitude /TP Type Aircraft /SK Sky Condition /TA Temperature (Celsius) /TB Turbulence /IC Icing /RM Remarks Reference: Page 37 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 93

/OV References location, using a VHF NAVAID or airport identifiers. /TM Is the time the reported phenomenon occurred or was encountered. /FL Altitude/flight level is reported in hundreds of feet (MSL) where a phenomenon was first encountered. /TP Aircraft type is mandatory for all icing and turbulence PIREPS. /SK Sky condition is the reported height of cloud bases, tops, and cloud coverage, in hundreds of feet MSL, in 3 digits. When more than one layer is reported, layers are separated by a slant (/). /IC The reported icing altitude is completed if different from the reported altitude element ( /FL ). /TB The reported turbulence altitude is completed if different from the reported altitude element ( /FL ). /RM Remarks are plain text to clarify previously reported elements or to add more information describing in flight weather. 94

PILOT REPORT (PIREP) Reporting Elements (Nearest Weather Reporting Station) SGF UA/ OV SGF040020 /TM 1550 /FL030 /TP C210 /SK OVC027-TOP060 /TA M08 /TB LGT-MDT CHOP /IC LGT-MOD MX /RM IC 027-060 When an Element is Not Reported It is Omitted Example: SGF UA/OV SGF040020 /TM 1500 /FL020 /TP C210 /TB MOD Reference: Page 37 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 95

Pilot Reports are coded to appear with the METAR location nearest the conditions being reported. On the previous slide, the sample Pilot Report at SGF is the Springfield-Branson Airport in Springfield, Missouri. If a pilot planned a flight to or from the Springfield airport, this PIREP would be available for review during the preflight weather analysis, since SGF is coded into the PIREP. 96

PILOT REPORT (PIREP) SGF UUA/ OV SGF /TM 1400 /FL030 /TP C210 /SK OVC037-TOP050 /TA M08 /TB LGT-MDT /RM LLWS DURGC Severe Icing Severe or Extreme Turbulence or CAT Low Level Wind Shear Hail -- Volcanic Ash Clouds Tornadoes Funnel Clouds Waterspouts Reference: Page 37 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 97

Urgent Pilot Reports are issued whenever any of the following phenomena occur: Severe Icing (SEV). Severe or extreme turbulence (SEV / XTRM) (including clear air turbulence (CAT). Low level wind shear (LLWS), with airspeed fluctuations of more than 10 knots. Large Hail (GR) and small hail (GS). Volcanic ash clouds. Tornadoes, funnel clouds, or waterspouts. Or any other weather phenomena an issuing FSS specialist considers hazardous to aircraft. 98

PILOT REPORT (PIREP) Always Note Type Aircraft Compare Intensities Airliner Light Aircraft MOD Turbulence Equates to SEV Turbulence MOD Icing Equates to SEV Icing Note Time of the PIREP to Determine Validity Reference: Page 37 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 99

Note the type of aircraft when evaluating pilot reports. A report of moderate turbulence for an airliner would likely translate to severe turbulence for a much smaller aircraft. The same comparison holds true for icing, as well. The age of a PIREP would be an important consideration, as well. Older PIREPs may no longer offer valid information, since the reported weather event may have significantly changed. 100

PILOT REPORT (PIREP) SGF UUA/ OV SGF /TM 1400 /FL030 /TP C210 /SK OVC037-TOP050 /TA M08 /TB LGT-MDT /RM LLWS DURGC RM = Remarks To Report Weather Not Included in Elements To Clarify Reporting Elements Low Level Wind Shear Entered Here To Report Weather at Altitudes Other Than Reporting Altitude Reference: Page 37 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 101

Remarks are for reporting weather not included in elements, or to clarify previously reported elements. Plain text can be used to describe the weather phenomena to clarify the event. Low level wind shear (LLWS) reports for departing and landing aircraft are typically listed here. Details on the occurrence of icing, turbulence, cloud cover, etc., will be noted here if the weather event occurred at a different altitude than the altitude of the aircraft at the time of the pilot report, or if an aircraft was climbing or descending. 102

TAF What is the Forecast at My Departure Airport? TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 5 Statute Mile Radius Reference: Page 38 - Preflight Weather Analysis Made Easy, by Find-it Fast Books, website www.finditfastbooks.org 103

Compare the TAF with the current weather for the same time period at your destination airport. Does the current weather and the TAF agree? Is the weather better or worse than forecast? If worse, be suspicious of the forecast. Look at weather trends upwind from your departure airport. Are they better or worse than forecast? Look for amended TAFs. Forecasters seldom ever issue amendments for improving weather. Typically, only TAFs are amended where the weather is deteriorating faster or lower than expected. A newly issued TAF is more accurate for the near future than the previous older TAF where the later portion of the older TAF covers your takeoff. If your schedule permits, get the fresh TAF. 104

TAF Terminal Aerodrome Forecast TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 24 Hour Airport Forecast 32 Air Carrier Airports -- 30 Hour Forecast Same Weather Code as METARs Reference: Page 47 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 105

A Routine Aviation Terminal Forecast, called a TAF, is a concise statement of the expected meteorological conditions at an airport during a specified period, usually 24 hours. 32 of the larger air carrier high-impact U.S. airports issue 30 hour TAFs. TAFs use the same weather code as found in METARs. 106

TAF Terminal Aerodrome Forecast TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 24 Hour Airport Forecast Issued Every 6 Hours 0000Z 0600Z 1200Z 1800Z Reference: Page 47 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 107

Looking at the 24 hour format on the TAF on the previous slide, its Valid Period and Time, begins at 1200Z, on the 5th of the month, and ends 24 hours later at 1200z, on the 6th of the month. Z = Coordinated Universal Time (UTC) 108

TAF Terminal Aerodrome Forecast TAF KSFO 051130Z 0512/0618 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 30 Hour Airport Forecast 32 Air Carrier Airports To Meet Long Haul Flight Requirements Reference: Pages 47, 49A - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 109

The change of the 24 hour format to 30 hours was made to meet the requirements of the International Civil Aviation Organization (ICAO) to provide a 30- hour TAF to support flight planning needs for long haul flights. Looking at the previous slide, this TAF s Valid Period and Time, the TAF forecast period begins at 1200Z, on the 5th of the month, and ends 30 hours later at 1800z, on the 6th of the month. The 30 hour TAFs have the same issuance times as the 24 hour TAFs: 0000Z 0600Z 1200Z 1800Z 110

TAF Terminal Aerodrome Forecast Type of Report TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 TAF = Routine TAF TAF AMD = Amended TAF Reference: Page 48 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 111

The report header will always appear as the first element in the TAF. There are two types of TAFs: A routine forecast, TAF; and an amended forecast, TAF AMD. An amended TAF is issued when the current TAF no longer adequately describes the ongoing weather or the forecaster feels the TAF is not representative of the current or expected weather. 112

TAF Terminal Aerodrome Forecast ICAO Station Identifier TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 K = International Civil Aviation Organization OKC = Oklahoma City, OK Reference: Page 48 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 113

The TAF code uses ICAO four-letter location identifiers as described in the METAR section. The K is the ICAO identifier for the United States. OKC is the location identifier for Oklahoma City, Oklahoma, Will Rogers World Airport. 114

TAF Terminal Aerodrome Forecast Date and Time of Origin TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 Date and Time the Forecast is Prepared Z = Coordinated Universal Time (UTC) Reference: Page 49 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 115

This element is the Coordinated Universal Time (UTC) date and time the forecast is actually prepared. The format is a two-digit date and four digit time followed by the letter Z. Routine TAFs are prepared and filed approximately one-half hour before scheduled issuance times. TAFs are scheduled for issuance four times daily at 0000Z, 0600Z, 1200Z, and 1800Z. 116

TAF Terminal Aerodrome Forecast Valid Period Date and Time TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 Valid Periods Beginning at 0000Z Indicated by 00 Valid Periods Ending at 0000Z Indicated by 24 Reference: Page 49 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 117

The Coordinated Universal Time (UTC) valid period of the forecast is a two-digit date followed by the twodigit beginning hour, a slanted line, then a two-digit date followed by the two digit ending hour. Routine TAF s are valid for 24 hours. Valid periods beginning at 0000Z are indicated as 00. Valid periods ending at 0000Z are indicated as 24. The 24 indication applies to all times ending at 0000Z. As mentioned before, 32 air carrier airports issue 30 hour TAFs. 118

. TAF Terminal Aerodrome Forecast Valid Period Date and Time TAFs Issued at Part-Time Stations: NIL AMD SKED AFT (closing time) Z (No Amended or Scheduled TAF) Added to End of Forecast Reference: Page 49 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 119

Where an airport or terminal operates on a part-time basis, less than 24 hours a day, the TAFs issued for those locations will have the abbreviated statement NIL AMD SKED AFT (closing time)z, added to the end of the forecast. 120

. TAF Terminal Aerodrome Forecast Valid Period Date and Time TAFs Issued While Part-Time Stations Closed: NIL -- In Place of Forecast Text RTD -- Delayed Forecast Issued After 2 Complete Observations Reference: Page 49 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 121

For TAFs issued while part-time locations are closed,the word NIL will appear in place of the TAF text. A delayed (RTD) TAF will then be issued for these locations after the reporting station opens and two complete observations are taken. 122

TAF Terminal Aerodrome Forecast Forecast Meteorological Conditions TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 Winds -- Visibility -- Weather -- Sky Condition Significant Changes Denoted With: FM BCMG TEMPO Reference: Pages 50-55 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 123

The basic format of winds, visibility, weather and obscurations, sky condition, and wind shear all make up the Body of the TAF. These elements are always listed on the top line, and in this order. If a significant, lasting change in any of these elements is expected during the valid period, a new time period, denoted with FM, BECMG, or TEMPO is included describing the changes. This will discuss this a little more, shortly. 124

TAF Terminal Aerodrome Forecast Wind TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 Surface Winds in Knots -- KT Highest Expected Gust -- G Reference: Pages 50, 51 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 125

The wind group includes forecast surface winds. The surface wind forecast is the expected direction from which the wind is blowing. The first three digits indicate wind direction. Wind speed is indicated by the last two digits, or three if 100 knots or greater. The contraction KT, follows to denote the units of wind speed in knots. Wind gusts are noted by the letter G appended to the wind speed followed by the highest expected gust (two digits, or three, if 100 knots or greater). 126

TAF Terminal Aerodrome Forecast Variable Winds VRB = Variable Associated With Thunderstorms or Low Winds Examples: VRB16G28KT - Wind Variable at One-Six, Gust Two-Eight VRB03KT - Wind Variable at Three Reference: Pages 50, 51 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 127

Variable winds are encoded when it is impossible to forecast a wind direction due to winds associated with thunderstorms or low wind speeds. A variable wind direction is noted by VRB where the three digit direction usually appears. Examples: VRB16G28KT - Wind variable at one six gust two eight. VRB03KT - Wind Variable at Three. 128

TAF Terminal Aerodrome Forecast Optional Data (Wind Shear) Non-Convective Low Level Winds (up to 2000 feet) Entered After Sky Conditions if Wind Shear Expected Example: WS010/18040KT Low level wind shear at one thousand, wind one eight zero at four zero Reference: Page 52 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 129

Wind shear is the forecast of non-convective low level winds (up to 2000 feet) and is entered after the sky conditions when wind shear is expected. The forecast includes the height of the wind shear followed by the wind direction and wind speed at the indicated height. Height is given in hundreds of feet AGL up to and including 2,000 feet. Wind shear is encoded with the contraction WS followed by a three-digit height, a slant, and winds at the height indicated in the same format as surface winds. 130

TAF Terminal Aerodrome Forecast TEMPO TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 TEMPO = Occasional Forecast Conditions Generally Lasting Less Than an Hour Reference: Page 55 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 131

Think of TEMPO as occasional. It s used to describe forecast conditions which are generally expected to last for less than an hour. In the TAF on this slide, TEMPO 0513/0516 1 1/2SM BR translates to: Occasional visibility one and one-half in mist (BR) between 1300 UTC and 1600 UTC on the fifth day. The next slide explains a very important point. 132

TAF Terminal Aerodrome Forecast TEMPO TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 TEMPO = Changing Conditions Only Basic Forecast in TAF Body Continues in Effect Reference: Page 55 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 133

In the TAF on the previous slide, TEMPO 0513/0516 1 1/2SM BR translates to: Occasional visibility one and one-half in mist (BR) between 1300 UTC and 1600 UTC on the fifth day. However, it s very important to understand that the TEMPO time period includes only those elements which are expected to change. The basic forecast in the TAF body of 14008KT 5SM BR BKN030 continues to apply during the TEMPO time period. 134

TAF Terminal Aerodrome Forecast FM TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 FM = After FM = A Rapid Change Over Less Than 1 Hour Reference: Page 54 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 135

Think of from (FM) as after. From (FM) is used to forecast a rapid change in prevailing conditions, occurring over less than an hour. Typically, a rapid change of prevailing weather conditions to a completely new set of prevailing conditions is associated with a synoptic feature passing through the area, such as warm or cold frontal passage. 136

TAF Terminal Aerodrome Forecast FM TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 Contains If Applicable: Winds -- Visibility -- Weather -- Sky Condition Reference: Page 54 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 137

Appended to the from (FM) indicator is the sixdigit date, hour, and minute the change is expected to begin. It continues until the next change group or until the end of the current forecast. Each from group (FM) contains all the required elements - wind, visibility, weather, and sky condition, if they apply. 138

TAF Terminal Aerodrome Forecast BECMG TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 BECMG = A Gradual Change -- Usually Within 2 Hours Change Occurs at Unspecified Time Within 2 Hour Period Reference: Pages 54, 55 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 139

The becoming group (BECMG) is used when a gradual change in conditions is expected over a longer time period, usually two hours. The gradual change will occur at an unspecified time within this two hour time period. The time period, when the change is expected, is two four-digit groups. The beginning date & hour and the ending date & hour are separated by a slant. 140

TAF Terminal Aerodrome Forecast PROB40 TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 PROB40 = A Chance -- 30% to Less Than 50% Of a Thunderstorm or Form of Precipitation Occurring Reference: Page 53 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 141

The PROB40 group is used when the occurrence of thunderstorms or precipitation is in the 30% to less than 50% range. Thus the probability value 40 is appended to the PROB contraction. The time period, during which the thunderstorms or precipitation is expected, is two four-digit groups. The beginning date & hour and the ending date & hour are separated by a slant. 142

TAF Terminal Aerodrome Forecast PROB30 TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB30 0600/0606 1SM TSRA OVC004CB BECMG 0606/0608 21015KT P6SM NSW SCT040 PROB30 = A Slight Chance -- 10% to 29% Of a Thunderstorm or Form of Precipitation Occurring Reference: Page 53 - The METAR & TAF Quick Reference Manual, by Find-it Fast Books, website www.finditfastbooks.org 143

The PROB30 group is used when the occurrence of thunderstorms or precipitation is in the 10% to 29% range. The time period, during which the thunderstorms or precipitation is expected, is two four-digit groups. The beginning date & hour and the ending date & hour are separated by a slant. 144

TAF Terminal Aerodrome Forecast NSW No Significant Weather A TAF TRAP! Refers to Visibility and Precipitation NOT Cloud Cover Clouds May Be Too Low for Safe VFR Flight! Reference: Page 38 - Preflight Weather Analysis Made Easy, by Find-it Fast Books, website www.finditfastbooks.org 145

The contraction NSW is defined as No Significant Weather. This indicates that obstructions to visibility or precipitation previously noted in a TAF is expected to end. Pay special attention to the forecast cloud coverage and bases, which could actually be quite low so low, in fact, that safe VFR flight is not at all possible! 146

AREA FORECAST (FA) What is the Forecast Along My Route of Flight? General Picture of VFR Clouds and Weather Always Check AIRMET Sierra for Any IFR Weather Cloud Bases Are Forecast as MSL Unless AGL or CIG Are Noted Cloud Tops Are Always MSL Reference: Pages 40, 41 - Preflight Weather Analysis Made Easy, by Find-it Fast Books, website www.finditfastbooks.org 147

An Area Forecast provides a general picture of VFR clouds and significant weather. Cloud bases are always forecast as MSL, unless AGL or CIG are noted. MSL means Mean Sea Level. AGL means Above Ground Level. CIG means Ceiling. When reviewing an Area Forecast, always check AIRMET Sierra for any IFR conditions expected along your route of flight. 148

AREA FORECAST (FA) Area Forecast Geographic Areas of Responsibility Each Area of Responsibility issues its own Area Forecast Issued 3 Times daily Reference: Pages 40, 41 - Preflight Weather Analysis Made Easy, by Find-it Fast Books, website www.finditfastbooks.org 149

As with AIRMETs and SIGMETs, Area Forecasts are issued within the Areas of Responsibility shown on the map on the previous slide. The National Weather Service s Aviation Weather Center in Kansas City, Missouri, issues area forecasts three times a day for six areas that cover the contiguous 48 states. Each Area Forecast consists of a 12 hour forecast, plus a 6 hour categorical outlook. 150

AREA FORECAST (FA) Header Precautionary Statement Synopsis VFR Clouds and Weather Section Reference: Pages 40, 41 - Preflight Weather Analysis Made Easy, by Find-it Fast Books, website www.finditfastbooks.org 151

Area Forecasts are written in abbreviated plain language using FAA standard contractions. All times are Coordinated Universal Time (UTC). Precipitation type and coverage are forecast, including thunderstorms. Visibilities are specified in statute miles. When using the Area Forecast, first look for the states that involve your planned route of flight. Then look for the state breakdowns associated with your route of flight to get a general VFR clouds weather picture. 152

The Header section lists: The issue time of Area forecast. The valid time of the synopsis (an 18 hour synopsis). A visual flight rules (VFR) CLOUDS/WX section, which is a 12 hour forecast, plus a 6 hour categorical outlook. And the areas of coverage by state identifier and coastal waters, if applicable. An Area Forecast can be: Amended (AMD) Corrected (COR) Delayed (RTD) 154

The Precautionary Statement section: Warns users to check the AIRMET Sierra for IFR and/or mountain obscuration. Describes the hazards associated with all thunderstorms. Reminds users that all altitudes are MSL, unless noted as AGL or CIG (ceiling) It would be easy to draw the conclusion that no IFR conditions are forecast by examining only the Area Forecast. Always remember that the Area Forecast discusses VFR CLOUDS AND WEATHER ONLY! Coverages of Thunderstorms (if forecast) include: ISOL (isolated) = single cells no percentage WDLY SCT (widely scattered) = less than 25% SCT or AREAS (scattered or areas) = 25% to 54% NMRS (numerous) = 55% or more WDSPRD (widespread) = 55% or more Always compare field elevation of airports with MSL cloud bases to estimate AGL cloud bases when reviewing the Area Forecast. 156

The Synopsis section: Provides a brief summary of the location and movement of fronts, pressure systems and circulation patterns for an 18 hour period. References to low ceilings, reduced visibility and/or strong winds may be included. The Synopsis applies to the pertinent weather within the Area Forecast region of responsibility. 158

The VFR CLOUDS and WX section: Contains a 12 hour specific forecast, followed by a 6 hour categorical outlook. Is broken down into geographical areas, and/or states. Describes clouds and weather affecting VFR flight operations, including precipitation, thunderstorms, and sustained surface winds 20 Knots or greater. The Area Forecast also includes visibility when the forecast to visibility is between 3 and 6 Statute Miles and/or obstructions to visibility. 160

The VFR CLOUDS and WX section, 6 hour categorical outlook uses the weather categories of: VFR: More accurately, VMC (visual meteorological conditions): Visibility > 5 miles AND ceiling > 3000 ft. MVFR: Marginal VFR: Visibility 3-5 miles OR ceiling 1000-3000 feet. IFR: More accurately, IMC (instrument meteorological conditions): Visibility 1-3 miles OR ceiling 500-1000 ft. LIFR: Low IFR: Visibility < 1 mile OR ceiling <500 feet. WND: WND in the categorical outlook means the winds during that period is forecast to be at least 20 knots or stronger. 162

ENROUTE FORECAST Using the TAFs TAF Coverage = 5 SM Can Supplement Area Forecast May Confirm Area Forecast May Contradict Area Forecast TAF Cloud Bases AGL Area Forecast Cloud Bases MSL 163

If you prefer using the TAFs as your enroute forecast tool, keep in mind that the TAFs forecast weather is within a localized area of the forecast station. TAFs may serve as a supplement to the Area Forecast, and in some cases may provide a more accurate appraisal of forecast weather. Using multiple resources can, however, give contradicting forecast data. And, keep in mind that TAF cloud bases are forecast as AGL whereas Area Forecast cloud bases are MSL unless otherwise noted as AGL or CIG. 164

TAF What s the Forecast at My Destination Airport TAF KOKC 051130Z 0512/0612 14008KT 5SM BR BKN030 TEMPO 0513/0516 1 1/2SM BR FM051600 16010KT P6SM SKC BECMG 0522/0524 20013G20KT 4SM SHRA OVC020 PROB40 0600/0606 2SM TSRA OVC008CB BECMG 0606/0608 21015KT P6SM NSW SCT040 Plus or Minus 2 Hours of ETA Compare With METARs Reference: Page 42 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 165

Examine the TAF for your destination airport for a time frame of plus or minus 2 hours of your estimated time of arrival (ETA). Compare the current weather at your destination with the forecast for the same time period (Think of this as an aftercast). Does the current weather and the past forecast period agree? If not, be suspicious of the forecast if the current weather is worse than the forecast indicated it would be. (Review the TAFs discussed on the earlier slides, if necessary.) 166

TAF Destination Airport Reasons Nearby TAFs May Differ: Elevation Differences Fog Prone Areas Bordering Forecast Areas Reference: Page 42 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 167

You may notice, in some situations, where neighboring airports in close proximity to one another have very different TAFs. This may be due to a significant difference in airport elevation, or a local weather causer, such as a fogprone river valley. Another explanation may be that the airports border separate National Weather Service Forecast Office areas of responsibility where different forecasters may issue dissimilar forecasts. 168

TAF Destination Airport If No TAF Issuance: Examine Area Forecast Area Forecast Cloud Bases MSL Note Airport Field Elevation to Determine AGL Cloud Bases Examine Neighboring TAFs Reference: Page 42 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 169

If your destination airport does not issue a TAF, examine the Area Forecast for a general idea of what to expect. Keep in mind that Area Forecast VFR cloud bases are forecast in MSL, unless otherwise stated as AGL or a ceiling (CIG). You must know the field elevation of your destination airport to estimate likely cloud bases upon arrival. Also examine the nearby TAFs to compare their forecast cloud bases and visibilities with the Area Forecast. Comparing TAFs might not be all that helpful in the more remote areas of the country, however, where distances between TAF locations are too far apart to be helpful. 170

WINDS ALOFT FORECAST (FB) What Are the Winds Aloft? Reference: Page 44 Preflight Weather Analysis Made Easy by Find-it Fast Books, website www.finditfastbooks.org 171