Monthly Long Range Weather Commentary Issued: July 9, 2012 Steven A. Root, CCM, President/CEO JUNE 2012

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1 Monthly Long Range Weather Commentary Issued: July 9, 2012 Steven A. Root, CCM, President/CEO JUNE 2012 June Background The average temperature for the contiguous United States during June was 2 F above the twentiethcentury NORMAL. Scorching temperatures during the second half of the month broke or tied over 170 alltime temperature records in cities across America. June temperatures also contributed to a record warm first half of the year and the warmest 12 month period the nation has experienced since recordkeeping began in 1895.

2 The map above shows where in the United States June 2012 temperatures were different from the NORMAL. Shades of red indicate temperatures up to 8 F WARMER THAN NORMAL, and shades of blue indicate temperatures up to 5 F COOLER THAN NORMAL the darker the color, the larger the temperature difference. The Intermountain West and much of the Great Plains are shaded in red, indicating the WARMER THAN NORMAL temperatures that persisted throughout June. Colorado has its warmest June on record, with a statewide temperature more than 6 F above average. Seven additional states in the region had a top ten warm June. COOLER THAN NORMAL temperatures were present for the Pacific Northwest, where Washington had its seventh coolest June on record. Cool conditions were also present for the Southeast, despite record warm temperatures towards the end of the month. Record breaking temperatures occurred across a large portion of the nation during the second half of June. Temperatures in South Carolina (113 F) and Georgia (112 F) are currently under review by the U.S. State Climate Extremes Committee as possible all time statewide temperature records. Despite the record heat late in the month, the month s average temperatures for the Lower 48 ranked only 14th warmest, with 1933 holding the record for the warmest U.S. June. According to the U.S. Drought Monitor, as of July 3, 56.0 percent of the contiguous U.S. experienced drought conditions, marking the largest percentage of the nation experiencing drought conditions in the 12 year record of the U.S. Drought Monitor. Drought conditions improved across Florida, due to the rains from Tropical Storm Debby. Drought conditions worsened across much of the West, Central Plains, and the Ohio Valley, causing significant impacts on agriculture in those regions.

3 Tropical Storm Debby brought copious precipitation to Florida during June as it slowly traversed the state. Florida s monthly statewide precipitation total of inches was 6.17 inches ABOVE NORMAL, ranking as the wettest June on record for the state. Parts of the Northeast, as well as the Pacific Northwest, were WETTER THAN NORMAL. Maine, Oregon, and Washington each had a top ten wet June. This very dry, warm, and windy weather created ideal wildfire conditions in June. Several large wildfires raged across the West, destroying hundreds of homes and causing the evacuation of tens of thousands of residences. Nationwide, wildfires scorched over 1.3 million acres, the second largest extent on record for June. Additionally, the areas of the contiguous U.S. experiencing drought conditions increased in June by almost 20 percent, leaving even more regions vulnerable to wildfires. June Increased Sunshine and Expanding Drought Summer officially began with the summer solstice this year on June 20 th, equating to longer days. By way of comparison, Chicago and New York now has more than 15 hours of sunlight per day versus about 9 hours per day during the winter solstice (on or near Dec. 21 st ). All locations in the Northern Hemisphere north of the Arctic Circle received 24 hours of daylight after June 20 th. The first day of summer brought a heat wave in the eastern USA as well as much southeasterm Canada (Ontario and Quebec). One hundred USA heat records were broken, some by as much as 15 F (8.3 C) and 51 records were tied. There are heat warnings for 13 states, and New York, Boston and Washington, D.C saw temperature records fall. Later in June, another heatwave blasted the entire central and eastern portions of the continent, breaking 1,011 US temperature records in a single week. Out of a possible 171,442 Daily Highest Max Temperatures, 2,284 were broken and (+) 998 were tied (a total of 3,2,82) during June so July is starting with a heat wave.

4 The most serious consequence of the increasing heat, however, has not been the temperatures, but rather the resulting evaporation rate. Much of the USA was left drought stricken by almost 2 years of La Niña conditions. Once the event ended in late March, the nation went through a warm spring and higher temperatures in the Great Plains and much of the Midwest the national grain belt. Even when these regions had normal to above normal rainfall, there was a higher than average evaporation rate. As a result, a nation that ended the La Niña with 56% of the lower 48 states with dry or drought conditions is now 72% dry. Even more seriously, the dried out areas are the most productive agricultural lands in the nation. Selected Records Preliminary Location Record Type Value Previous Record (date) Portland, Maine Pensacola, Florida Sidney AP, Nebraska Tribune, Kansas Goodland, Kansas Hill City, Kansas Colby, Kansas Gainesville, Florida Fourth wettest day in June on record Second highest all time calendar day rainfall on record (tied) (tied) (tied) All time wettest June on record 3.63 June " the wettest day occurred on June 18, 1922 with 4.35" 13.13" June 9 N/A the highest occurred on October 5, 1934 with 15.29" 111 F June F June F June F June F June " June F June 25, F June 23, F June F June 26, F June 24, " June 1965

5 Location Record Type Value Previous Record (date) Gainesville, Florida Gainesville, Florida Gainesville, Florida Little Rock Adams Field, AR North Little Rock, Arkansas Denver Int l AP, Colorado Denver Int l AP, Colorado Russellville, Arkansas Batesville AP, Arkansas Hot Springs AP, Arkansas Jacksonville/L. Rock AFB, AR Tampa, Florida Miles City, Montana June wettest calendar day rainfall on record All time second highest calendar day rainfall on record All time second highest three(3) day rainfall on record (tied) record (tied) Wettest June on record 6.95" June " June 27, " June 9 N/A the highest occurred on October 24, 1938 with 7.42" 12.02" June N/A the highest occurred on September 25 27, 1894 with 12.68" 106 F June F June F June F June F June F June F June F June 20, 1936 June 29, 1988 and June25, F June 25, F F July 20, F June 28, F June 30, F June 29, F June F June 22, " as of June " June F June F June 23 and 24; 2007 July 14, 2002; August 7, 1995; August 7, 1949 Miles City, Montana Driest June on record 0.36" 0.51" June 2006 Billings, Montana Driest June on record (tied) 0.24" 0.24" June 1961 Scottsbluff AP, Nebraska Chadron AP, Nebraska McCook, Nebraska Yuma, Colorado Austin Camp Mabry, Texas Jacksonville, Florida (tied) (tied) record All time two(2) day rainfall record 106 F June F June F June F June F June " June F June 25, 2012 and June 26, F June 29, F July 20, F June 19, F June 14, " September 9 10, 1908

6 Location Record Type Value Previous Record (date) Indianapolis Int l AP, Indiana Indianapolis Int l AP, Indiana St. Louis, Missouri Columbia Reg l AP, Missouri Harrison, Arkansas Fort Wayne, Indiana Louisville, Kentucky Evansville, Indiana Dayton, Ohio Springfield, Missouri Vichy Rolla, Missouri West Plains, Missouri Madison/Dane County AP, WI Atlanta, Georgia Macon, Georgia 104 F June 28 Driest June on record 0.09" record (tied) (tied) (tied) (tied) 108 F June F June F June F June F June F June F June F June F June F June 28 Driest June on record 0.31" (tied) 106 F June F June F June 25, " June F June 25, 1952 and June 16, F June 19, F June 20, F June 28, 1988 July 14, 1936 and July 22, F June 28, F June 30, F June F June 27, F June F June " June F June F June 1980 Columbus, Georgia 106 F June F June 29, 2012 Juneau Int l AP, Alaska Wettest June on record 6.69" 6.22" June 1996 Salt Lake City AP, Utah Driest June on record (tied) Trace Trace June 1994 Apalachicola Muni AP, Wettest June on record 21.60" Florida 18.32" June 1965 Kalispell, Montana Wettest June on record 6.20" 5.66" June 2005

7 What a difference a year makes here is the LONG TERM PALMER DROUGHT conditions during JUNE 2011: and the same presentation at the end of MAY 2012: While Palmer's indices are water balance indices that consider water supply (precipitation), demand (evapotranspiration) and loss (runoff), the Standardized Precipitation Index (SPI) is a probability index that considers only precipitation.

8 The SPI is an index based on the probability of recording a given amount of precipitation, and the probabilities are standardized so that an index of zero indicates the median precipitation amount (half of the historical precipitation amounts are below the median, and half are above the median). The index is negative for drought, and positive for wet conditions. As the dry or wet conditions become more severe, the index becomes more negative or positive. The SPI is computed by NCDC for several time scales, ranging from one month to 24 months, to capture the various scales of both short term and long term drought.

9 Here is the current DROUGHT OUTLOOK, extending through Sept. 30, 2012:

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15 Western states reservoir storage remains generally lower than this same time last year:

16 The following graphic shows the upper level storm track, measured at approximately 18,000 feet above sea level, averaged for JUNE 2012: Notice that the main core of the jet (5,400 to 5,600 meter heights, PURPLE to light GREEN) is located well north, well into central and northern Canada, similar to the positions of the past 6 months, except over the Pacific Northwest (an area of COLDER THAN NORMAL temperatures and WETTER THAN NORMAL rainfall). This displacement of the main jet stream core during JUNE 2012 is quite evident in the departure from normal positioning (below), again reinforcing the ABOVE NORMAL temperatures observed nationwide during last month.

17 Our long range forecast model did extremely well last month predicting ABOVE NORMAL temperatures over most of the country, yet under stated the extreme warmth across the central Rockies, amd missed the BELOW NORMAL areas in OR, WA, GA, SC and NC. Our extended precipitation forecast for JUNE 2012 did fairly well also, and I was quite pleased with the verification of precipitation across the Pacific NW. These graphics depict our model forecasts for JUNE 2012 made at the end of MAY 2012: These graphics depict actual conditions occurring in JUNE 2012: The following graphics depict JUNE 2012 departure from normal temperatures compared to those of JUNE 2011 (this year to last year; LY to TY ):

18 The following graphics depict JUNE 2012 departure from normal precipitation compared to JUNE 2011 (this year to last year; LY to TY ): The following presentation shows monthly statistics for our climate region hub cities : Regional City and State MO. TEMPS ( F) MO. PRECIP. (ins.) MO. SNOWFALL (ins.) OBS NOR DFN OBS NOR DFN (%) OBS NOR DFN Honolulu HI % Seattle WA % Portland OR % Spokane Intl WA % Pendleton OR % Santa Rosa CA % LA Airport CA % Redding CA % Sacramento CA % Fresno CA % Winnemucca NV % Tonopah NV % Phoenix AZ % Albuquerque NM % Salt Lake City UT % Grand Junction CO % OBS = Observed; DFN = Departure from Normal

19 Regional City and State MO. TEMPS ( F) MO. PRECIP. (ins.) MO. SNOWFALL (ins.) OBS NOR DFN OBS NOR DFN (%) OBS NOR DFN Great Falls MT % Casper WY % Denver CO % Grand Forks ND % Rapid City SD % Omaha NE % Kansas City MO % Oklahoma City OK % Lubbock TX % Dallas Ft. Worth TX % San Antonio TX % Minneapolis MN % Green Bay WI % Detroit MI % Regional City and State OBS = Observed; DFN = Departure from Normal MO. TEMPS ( F) MO. PRECIP. (ins.) MO. SNOWFALL (ins.) OBS NOR DFN OBS NOR DFN (%) OBS NOR DFN Buffalo NY % Burlington VT % Boston MA % Pittsburgh PA % Philadelphia PA % Baltimore MD % Chicago O'Hare IL % Indianapolis IN % Louisville KY % New Orleans LA % Raleigh Durham NC % Wilmington NC % Atlanta GA % Tallahassee FL % Orlando FL % OBS = Observed; DFN = Departure from Normal

20 Regional City and State OBS = Observed; DFN = Departure from Normal MO. TEMPS ( F) MO. PRECIP. (ins.) MO. SNOWFALL (ins.) OBS NOR DFN OBS NOR DFN (%) OBS NOR DFN Prince George BC % Edmonton AB % Saskatoon SK % Winnipeg MB % Kenora ON % Timmins ON % Muskoka ON % Toronto ON % Ottawa ON % Barrow AK % Nome AK % Fairbanks AK % Anchorage AK % Juneau AK % Regional City and State MO. TEMPS ( F) MO. PRECIP. (ins.) MO. SNOWFALL (ins.) OBS NOR DFN OBS NOR DFN (%) OBS NOR DFN Continental US % So. Canada % Alaska % Equally Weighted Inputs of Hub Cities ENSO neutral conditions have prevailed since the weak/moderate strength La Niña ended in April As of mid June, SST anomalies in the east central tropical Pacific are just slightly positive except for a small region close to the dateline where they are still very close to average. Since February, SSTs have been WARMER THAN NORMAL in the far eastern part of the tropical Pacific basin. While the strength of these positive anomalies has diminished in the last month or two, the area of somewhat above average SSTs has expanded westward to about 140W longitude. For May the SST anomaly in the NINO3.4 region was 0.05 C, indicative of neutral ENSO conditions, and for the February April season the anomaly was 0.34 C. Since December 2011, the IRI's definition of El Niño conditions began following that of NOAA/Climate Prediction Center, in which the SST anomaly in the NINO3.4 region (5S 5N; 170W 120W) exceeds 0.45 C. Similarly, for La Niña, the anomaly must be 0.45 C or less. The climatological probabilities for La Niña, neutral, and El Niño conditions vary seasonally, and are shown in a table at the bottom of this page for each 3 month season. The most recent weekly SST anomaly in the NINO3.4 region is 0.x C, indicating near average conditions in the tropical Pacific; this is barely warmer than the 0.05 C level observed in May.

21 The official diagnosis and outlook was issued earlier this month in the NOAA/Climate Prediction Center ENSO Diagnostic Discussion, produced jointly by CPC and IRI. It carried an El Niño watch, and gave a probability of exactly 50% for El Niño conditions developing during late northern summer or early fall. It also stated that neutral conditions are expected to persist at least into part of northern summer. Now, in the middle of June, a new set of model ENSO predictions is available as shown in the IRI/CPC ENSO prediction plume, discussed below. The current east central tropical Pacific SSTs are in ENSO neutral territory, and are just slightly in the warm direction in terms of SST and the basin wide sea level pressure pattern. Low level zonal winds and anomalous convection have been near average and have not yet swung toward an El Niño state. Subsurface temperatures across the equatorial Pacific have now risen to become mildly to moderately ABOVE NORMAL in the upper part of the ocean from just east of the date line eastward to 90W, and also in the western Pacific. A weakness in this subsurface warmth is found near the dateline. The thermocline depth along the equator is now above average across most of the tropical Pacific, an exception being a stretch of longitude near the dateline where the thermocline is just slightly shallower than average as a weak remnant of the La Niña that dissipated in early April, more than 2 months ago. As of mid June, some of the dynamical models and all of the statistical models predict ENSO neutral conditions for the Jun Aug season. However, nearly all models then indicate warming from their starting anomaly values (for Jun Aug) onward, so that for the subsequent seasons most dynamical models predict development of El Niño conditions. However, by contrast, most statistical models predict persistence of neutral conditions through the remainder of For the Jun Aug season, 69% of models indicate neutral ENSO conditions, while 31% indicate development of El Niño conditions. By late northern summer/autumn in Aug Oct, 46% indicate neutral conditions and 58% predict El Niño conditions. At lead times of 3 or more months into the future, statistical and dynamical models that incorporate information about the ocean's observed subsurface thermal structure generally exhibit higher predictive skill than those that do not. For the Sep Nov season, among models that do use subsurface temperature information, 36% predict ENSO neutral SSTs, and 64% predict El Niño conditions. For all models, the preference for El Niño conditions maximizes for the Oct Dec season (at 56%), and declines to levels below 50% for Nov Jan and later.

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23 WeatherBank Forecast In late June, I reviewed the trend mapping pattern or comparisons for all years, using this period to isolate the trends: MAY 1st JUN 19th and found these anomalies of the current period across North America: All previous trends were reconsidered and all years were again reviewed 1962 and 1964 had promise, but were eliminated since their 06/20 Æ 07/15 was off current trend, and especially the 07/15 Æ 09/01 for 1964 was way off Those years still in the existing trend matching years are: and 2011 (even though trend was dissimilar out West); too much cold in Southern Canada caused me to eliminate year 2000.

24 Next I compared each year June 21st to July 15th, to isolate the developing trends : and then, the 2nd part of the summer, July 15th to Sept. 1st: I like all years There are, of course, pockets of geography where past actual DFN s don t match up perfectly but overall, these years are still good trend analogs. Lastly, various combinations of the remaining four trend years were applied, to best capture the existing trends; here is the target (balance of the month of June forecasted), followed by predictive trends running through next Spring using these same calibrations applied from JUNE:

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26 so we end with these inputs (not that far off or different than what was installed last month): 20%, 40%, 20%, and 20%

27 Here is the most current ECMWF model output: Probability of TEMPS exceeding NORMAL Probability of TEMPS exceeding UPPER THIRD (Tercile)

28 Probability of TEMPS exceeding NORMAL Probability of TEMPS exceeding UPPER THIRD (Tercile)

29 Probability of TEMPS exceeding NORMAL Probability of TEMPS exceeding UPPER THIRD (Tercile)

30 Probability of TEMPS exceeding NORMAL Probability of TEMPS exceeding UPPER THIRD (Tercile) ***** CAUTION STATEMENT ***** I have applied trends from significantly different weather periods to best capture SUMMER and FALL 2012; while this approach allows me to forecast Summer as desired, caution is urdged since these trends have a dissimilar ENSO pattern than that which is predicted moving into Winter , and thus confidence is LOW for DEC 2012 and beyond.

31 Thus, WeatherBank s forecast is as follows: JULY 2012 Monthly Temperature Departures JULY 2012 Monthly Precipitation Departures AUGUST 2012 Monthly Temperature Departures AUGUST 2012 Monthly Precipitation Departures SEPTEMBER 2012 Monthly Temp. Departures SEPTEMBER 2012 Monthly Precip. Departures

32 WeatherBank s 2012 Summer Forecast Monthly CCDs for SUMMER 2012 (out of 63 past summers from 1950, GCS = Gas Consuming States): Forecast Made May 1, 2012: Summer 2012 Full USA: 53,608 CDDs; 22 nd Hottest Summer 2012 GCS: 25,882 CDDs; 14 th Hottest Forecast Made June 4, 2012: Summer 2012 Full USA: 57,503 CDDs; 9 th Hottest Summer 2012 GCS: 27,433 CDDs; 7 th Hottest Forecast Made July 1, 2012: Summer 2012 Full USA: 58,473 CDDs; 7 th Hottest Summer 2012 GCS: 28,016 CDDs; 5 th Hottest Summer 2011: Summer 2010: Summer 2009: Summer 2008: Summer 2007: 5 Year Summer Average: 10 Year Summer Average: HOTTEST SUMMER since 1950: COLDEST SUMMER since 1950: 60,402 CDDs; #1 Hottest 58,910 CDDs; #4 Hottest 50,048 CDDs; #39 Hottest 53,934 CDDs; #20 Hottest 58,404 CDDs; #7 Hottest 55,380 CDDS 55,547 CDDs 2011, 60,402 CDDs 1965, 43,337 CDDs

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38 Background Methodology for the WeatherBank LROM Using observed calendar day MAX and MIN temperatures at major cities across North America, WeatherBank generates daily Heating Degree Days (HDDs) and Daily Cooling Degree Days (CDDs). By comparing observations of HDDs in winter and CDDs during summer, one may obtain a real time description of how warm or cold the current season is. Basically, the hotter a location is in summer, or colder in winter, the more degree days that location earns. By adding all degree days from all locations, one can obtain a relative description of the current season. By comparing the current season to the degree days totals for past seasons, one obtains a ranking of the current season. WeatherBank's Long Range Outlook Model (LROM) fundamentally assumes that future weather patterns will be similar to a highly correlating, past weather pattern that was determine by trend composite. All similar weather trends of the past are compared to the current weather trend, then analyzed using a variety of tests. Global inputs such as MEI, average upper level flow patterns, etc., are also used. Correlation coefficients for each input years are generated, and used to define the relative strength of each year and how that trend could be used in the forecast process. Since mid August 2007, strong correlations have remained between the equally weighted (same calendar 13 week period called current, to the same 13 week period of all past years; no lag applied) time periods of the past.