Impact of the Loss of QuikSCAT on NOAA NWS Marine Warning and

Transcription

1 Impact of the Loss of QuikSCAT on NOAA NWS Marine Warning and Forecast Operations Joseph Sienkiewicz 1 Michael J. Brennan 2, Richard Knabb 3, Paul S. Chang 4, Hugh Cobb 2, Zorana J. Jelenak 5, Khalil A. Ahmad 4, Seubson Soisuvarn 4, Affiliations 1 NOAA Ocean Prediction Center David Kosier 1, 2 Tropical lprediction i Center George Bancroft 1 3 The Weather Channel 4 NESDIS StAR OVWST, Barcelona Spain 5 UCAR 1

2 High resolution Ocean Surface Vector Winds (OSVW) fully integrated into operations Twice daily near complete wind field Increased situational awareness Improved ddetection and warning capability Enhanced understanding of winds over oceans Allowed focus on extreme cyclones (Hurricane Force) QuikSCAT May 19, 2010 OVWST, Barcelona Spain 2

3 Without QuikSCAT Forecasters now soley rely on: Satellite Interpretation Skills NWP Analyses and short-term forecasts ASCAT Ship and buoy observations Situational awareness is reduced Consistency and confidence reduced May 19, 2010 OVWST, Barcelona Spain 3

4 Impact of QuikSCAT Loss Tropical Analysis and Forecast Branch 10 year climatology of Gulf of Tehuantepec gap wind events based on QuikSCAT showed an average of 6 to 8 storm force events per cold season TAFB issued a total of 15 Gale and 5 Storm warnings for the area during the cold season based on improving NWP model output, but could not get confirmation of the Storm warnings from ASCAT Brennan et al. (2010) Wea. Forecasting Typically 1 ASCAT pass per day hits this region, compared to 2 QuikSCAT passes on most days From Jan Mar 2010, TAFB issued 20 Gale warnings in their Atlantic waters, 9 in the Gulf of Mexico, and 4 in the Caribbean May 19, 2010 OVWST, Barcelona Spain 4

5 Case Example 8 14 January 2010 Gulf of Mexico Gale/Tehuantepec Storm Surface analysis, ship/buoy obs and ASCAT every 6 h from 8 14 January May 19, 2010 OVWST, Barcelona Spain 5

6 Case Example 8 14 January 2010 Gulf Gale/Tehuantepec Storm Only 5 ASCAT hits on the Gulf of Tehuantepec in a 7 day period Strongest ASCAT winds kt on 10 Jan No ASCAT data in region from 03 UTC 9 Jan through 15 UTC 10 Jan and from 15 UTC 10 Jan to 04 UTC 12 Jan 3 storm force ship observations Only a couple ASCAT gale force retrievals in far SW Gulf of Mexico Summary of lost capability bl due to loss of QuikSCAT Ability to capture storm force winds Full outline of area impacted by gale force winds in strongest events Ability to compare the model wind field with observations over a large spatial area Decreased forecaster confidence for severity, coverage, and timing of most extreme events May 19, 2010 OVWST, Barcelona Spain 6

7 Specific events Dec 9, 2009 Hawaii big wave event Tropical Storm Nida other than satellite data and without QuikSCAT data the ability to measure winds for these islands has been severely hampered making it difficult to verify any tropical system. Jan, 2020 C/V Horizon Hunter damaged en route to Guam diverted to Hawaii May 19, 2010 OVWST, Barcelona Spain 7

8 Hurricane Force Observations (Oct 07 ~ May 08 ) QS km QS - 25 km AS - opr AS - new GFS OBS

9 QuikSCAT vs. NCEP Global Forecast System OVWST, Barcelona Spain May 19,

10 April 23, 2010 Forecaster tools the Quandary Satellite imagery interpretation etat Result 986 STORM Surface observations Reality do not know intensity ASCAT NWP Analyses/forecasts May 19, 2010 OVWST, Barcelona Spain 10

11 % Wind Error QSCAT 25 km NRT vs. GDAS Aug 08 Jun 09 GALE STORM HURRICANE FORCE May 19, 2010 OVWST, Barcelona Spain 11

12 Hurricane Force Extra tropical Cyclones Detection and Warning Trend using QuikSCAT WARNING CATEGORIES Pre- QSCAT50 1. GALE kt 2. STORM >48 C y 40 c kt l o n e 30 s QSCAT ERA 1. GALE kt 2. STORM kt 3. HURCN FORCE > 64 kt Hurricane Force Warning Initiated Dec 2000 Detection increased with: -Forecaster familiarity -Data availability -Improved p resolution o -Improved algorithm Hurricane Force Wind Warning Initiated Dec km QuikSCAT Available in N AWIPS Oct km QuikSCAT available May Improved wind algorithm and rain flag Oct Atlantic Pacific Totals A 289 QuikSCAT Launch 14 Jun P May 19, 2010 OVWST, Barcelona Spain 12

13 Forecaster estimated Hurricane Force cyclones Sep 09 Apr With 5 QSCAT 0 Atlantic Atl below previous 5 40 yr average (43) DJFMA (32.6) 22 Pacific Pac at avg. (40.2) DJFMA (29.8) 28 Atlantic *highly subjective post QuikSCAT Pacific May 19, 2010 OVWST, Barcelona Spain 13

14 10 Forecaster estimated Hurricane Force cyclones Monthly Distribution vs average 9 8 QuikSCAT Failure Nov Atlantic Average 4 Atlantic Pacific 6% reduction vs. 5 yr avg QuikSCAT Failure Nov 09 0 Sept Oct Nov Dec Jan Feb Mar Apr Pacific Average Atlantic 33% reduction vs. 5 yr avg. 4 Pacific May 19, 2010 OVWST, Barcelona SeptSpain Oct Nov Dec Jan Feb Mar Apr 14

15 Forecaster verification 48,96 Pacific, Atlantic Probability of Detection (POD) 0.4 POD 48_PAC_HF POD 48_PAC_Storm POD 48_PAC_Gale Pac 48 Atl ONDJFM * (DJFM) Only POD 48_ATL_HF POD 48_ATL_Storm POD 48_ATL_Gale POD 96_PAC_HF POD 96_ATL_HF 0.3 POD 96_PAC_Storm 0.3 POD 96_ATL_Storm 0.2 POD 96_PAC_Gale 0.2 POD 96_ATL_Gale Pac Atl 96 May 19, 2010 OVWST, Barcelona Spain 15

16 Forecaster verification 48,96 Pacific, Atlantic False Alarm Rate(FAR) _PAC_HF _PAC_Storm 48_PAC_Gale Pac 48 Atl _ATL_HF ONDJFM * (DJFMA) Only 48_ATL_Storm 48_ATL_Gale _PAC_HF _PAC_Storm _ATL_HF _ATL_Storm 96_PAC_Gale _ATL_Gale Pac Atl 96 0 May 19, 2010 OVWST, Barcelona Spain 16

17 Summary Have lost OVW consistency for dfii defining warnings relying heavily on imagery, NWP and ASCAT less observed HF cyclones (Atlantic) nearly all not verified by observations cyclone verification suggests forecasters growing greliance on NWP to estimate warning categories (HF cyclones) Need to compare NWP analyses to forecaster estimated warnings NWP (GDAS) low bias for warning categories (compared to QSCAT) less storm force in Gulf of Tehuantepec less able to define warning areas need to examine other orographic jets (Greenland Tip Jet) W Pacific cyclones reduced detection capability Atlantic hurricanes impact still to be determined May 19, 2010 OVWST, Barcelona Spain 17

18 Impact of QuikSCAT Loss Tropical Cyclones NHC has not had any TCs develop in its AOR since the failure of QuikSCAT Likely impacts going forward into 2010 season: Loss of useful data for the analyzing the location, intensity, and structure of TCs, particularly those that are not sampled by aircraft reconnaissance Even ASCAT hits often fail to sample the entire TC circulation Reduced capability to identify winds above tropical storm force due to resolution and retrieval algorithm issues Degraded analysis of 34 kt wind radii in major hurricanes not sampled by aircraft reconnaissance Fewer passes over formative systems QuikSCAT was occasionally helpful in making the decision to initiate advisories May 19, 2010 OVWST, Barcelona Spain 18

19 Great Circle Ray Tracing North coast New Guinea Dec GFS Dec f045 QS Dec KTS GFS Dec f033 GFS Dec f021 May 19, 2010 OVWST, Barcelona Spain 19