Assessment of ASCAT High Wind Retrievals within Extratropical Cyclones at NOAA Ocean Prediction Center Khalil A. Ahmad NOA...
NOAA Ocean Prediction Center <ul><li>Issue marine warnings, forecasts,  </li></ul><ul><li>and guidance (text and graphical...
HF Extratropical Cyclone Intense, non-tropical cyclones  with hurricane force winds Feb 09, 2007, North Atlantic kts
HF Extratropical Cyclones  Detection and Warning using QuikSCAT <ul><li>Hurricane Force Warning Initiated Dec 2000  </li><...
<ul><li>Fan-beam, C-band radar  </li></ul><ul><ul><li>V-pol antennas </li></ul></ul><ul><li>Non-continuous 1100 km (2 x 55...
ASCAT vs. QuikSCAT Wind speeds  (Extratropical Cyclones) Operational ASCAT   QuikSCAT
ASCAT vs. QuikSCAT Wind speeds  (Extratropical Cyclones) New  ASCAT   QuikSCAT
Operational ASCAT wind product detects STORM force wind. One wind warning category lower than the actual winds. North Atla...
North Pacific Extratropical Storm Example QuikSCAT data reveals an area of HURRICANE force winds Operational ASCAT wind pr...
North Pacific Extratropical Storm Example QuikSCAT data reveals an area of HURRICANE force winds Operational GFS wind prod...
HF Extratropical Cyclone Database Surface Analysis Storm ID Date Lat Lon Type Pres Surface Analysis Storm track PAC011007 ...
Hurricane Force Observations ( Oct’07 ~ May’08 ) 212 188 2 39 38 19
Read HF Cyclone Info. Extract QS & ASCAT Data  & Perform QC (land, ice, coast, rain) flags Storm track  database Generate ...
Mean Wind Speed Field  <ul><li>Range rings  </li></ul><ul><li>1000 km increments </li></ul>kts QuikSCAT Opr ASCAT New ASCAT
<ul><li>Range rings  </li></ul><ul><li>1000 km increments </li></ul>Hurricane Force Wind Frequency  New ASCAT Opr ASCAT Qu...
<ul><li>Range rings  </li></ul><ul><li>1000 km increments </li></ul>Storm Force Wind Frequency  QuikSCAT Opr ASCAT New ASCAT
<ul><li>Range rings  </li></ul><ul><li>1000 km increments </li></ul>Gale Force Wind Frequency  QuikSCAT Opr ASCAT New ASCAT
Summary <ul><li>ASCAT is the only data source of satellite OSVW operationally available to </li></ul><ul><li>OPC forecaste...
CFRSL Group
Backup Slides
QuikSCAT Jun1999 ~ Nov 2009 <ul><li>Pencil-beam, Ku-band radar </li></ul><ul><ul><li>H-pol & V-pol </li></ul></ul><ul><li>...
<ul><li>Fan-beam, C-band radar  </li></ul><ul><ul><li>V-pol antennas </li></ul></ul><ul><li>Non-continuous 1100 km (2 x 55...
Operational ASCAT Sonde Wind Speed 28.8m/s SFMR 28 m/s ASCAT 22 m/s
New  ASCAT Sonde Wind Speed 28.8m/s SFMR 28m/s New ASCAT 25m/s
 
 
The nadir gaps increase the frequency at which ASCAT data do not sample or only partially sample weather systems of intere...
ASCAT QC Flag New ASCAT QC flag needs tunning
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TU4.L10 - ASSESSMENT OF ASCAT HIGH WIND RETRIEVALS WITHIN EXTRATROPICAL CYCLONES AT NOAA OCEAN PREDICTION CENTER

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  • 12 UTC
  • A Loss of QuikSCAT data will result in ~ 90% reduction in detection of hurricane force winds at Ocean Prediction Center
  • TU4.L10 - ASSESSMENT OF ASCAT HIGH WIND RETRIEVALS WITHIN EXTRATROPICAL CYCLONES AT NOAA OCEAN PREDICTION CENTER

    1. 1. Assessment of ASCAT High Wind Retrievals within Extratropical Cyclones at NOAA Ocean Prediction Center Khalil A. Ahmad NOAA/NESDIS/StAR – Dell Perot Systems Zorana Jelenak 1 , Joseph Sienkiewicz 2 , and Paul Chang 1 1 NOAA/NESDIS/StAR 2 NOAA/NWS/NCEP/OPC 2010 IEEE International Geoscience and Remote Sensing Symposiom 25 - 30 July 2010 Honolulu, HI
    2. 2. NOAA Ocean Prediction Center <ul><li>Issue marine warnings, forecasts, </li></ul><ul><li>and guidance (text and graphical) </li></ul><ul><li>Customers : </li></ul><ul><li>commercial mariners, fishermen, </li></ul><ul><li>recreational sailors, the USCG </li></ul><ul><li>and the U.S. Navy. </li></ul><ul><li>Mission: safety at sea, </li></ul><ul><li>protection of life and property </li></ul><ul><ul><li>Warning Categories: </li></ul></ul><ul><ul><li>GALE: 34 - 47 knots </li></ul></ul><ul><li>STORM : 48 - 63 knots </li></ul><ul><li>HURRICANE FORCE: > 64 knots </li></ul>
    3. 3. HF Extratropical Cyclone Intense, non-tropical cyclones with hurricane force winds Feb 09, 2007, North Atlantic kts
    4. 4. HF Extratropical Cyclones Detection and Warning using QuikSCAT <ul><li>Hurricane Force Warning Initiated Dec 2000 </li></ul><ul><li>Detection increased with: </li></ul><ul><ul><li>Forecaster familiarity </li></ul></ul><ul><ul><li>Data availability </li></ul></ul><ul><ul><li>Improved resolution </li></ul></ul><ul><ul><li>Improved algorithm </li></ul></ul>QuikSCAT Launch Jun 99 Hurricane Force Wind Warning Initiated Dec 00 25 km QuikSCAT Available in N-AWIPS Oct 01 12.5 km QuikSCAT available May 04 Improved wind algorithm and rain flag Oct 06 Totals A-289 P-269 558 WARNING CATEGORIES Pre- QSCAT 1. GALE 34-47 kt 2. STORM > 48 QSCAT ERA 1. GALE 34-47 kt 2. STORM 48 -63 kt 3. HURCN FORCE > 64 kt
    5. 5. <ul><li>Fan-beam, C-band radar </li></ul><ul><ul><li>V-pol antennas </li></ul></ul><ul><li>Non-continuous 1100 km (2 x 550 km </li></ul><ul><li>with a 720 km gap) swath. </li></ul><ul><li>Wind speed low bias at high winds </li></ul><ul><li>Wind products at 50 & 25 km horizontal </li></ul><ul><li>resolutions. </li></ul>ASCAT Fully Integrated into OPC operations
    6. 6. ASCAT vs. QuikSCAT Wind speeds (Extratropical Cyclones) Operational ASCAT QuikSCAT
    7. 7. ASCAT vs. QuikSCAT Wind speeds (Extratropical Cyclones) New ASCAT QuikSCAT
    8. 8. Operational ASCAT wind product detects STORM force wind. One wind warning category lower than the actual winds. North Atlantic Extratropical Storm Example New ASCAT Operational ASCAT QuikSCAT QuikSCAT & New ASCAT wind products detects HF wind. kts
    9. 9. North Pacific Extratropical Storm Example QuikSCAT data reveals an area of HURRICANE force winds Operational ASCAT wind product detects only GALE force wind. Two wind warning categories lower than the actual winds. New ASCAT wind product detects STORM force wind. One warning category lower New ASCAT Operational ASCAT QuikSCAT kts
    10. 10. North Pacific Extratropical Storm Example QuikSCAT data reveals an area of HURRICANE force winds Operational GFS wind product detects only GALE force wind. Two wind warning categories lower than the actual winds. New ASCAT wind product detects STORM force wind. One warning category lower New ASCAT Operational GFS QuikSCAT kts
    11. 11. HF Extratropical Cyclone Database Surface Analysis Storm ID Date Lat Lon Type Pres Surface Analysis Storm track PAC011007 2007100712 43.93 -169.72 1013 L PAC011007 2007100718 43.23 -164.06 1010 G PAC011008 2007100800 42.37 -158.38 1010 G PAC011008 2007100806 41.33 -152.07 1007 G PAC011008 2007100812 39.87 -143.82 998 S PAC011008 2007100818 40.76 -137.83 974 S PAC011009 2007100900 43.15 -134.94 970 H PAC011009 2007100906 44.46 -134.08 964 H PAC011009 2007100912 46.45 -132.94 966 H PAC011009 2007100918 47.51 -132.81 968 H PAC011010 2007101000 48.90 -132.36 967 S PAC011010 2007101006 50.65 -132.3 964 S PAC011010 2007101012 52.17 -132.36 975 G PAC011010 2007101018 53.67 -131.68 977 G
    12. 12. Hurricane Force Observations ( Oct’07 ~ May’08 ) 212 188 2 39 38 19
    13. 13. Read HF Cyclone Info. Extract QS & ASCAT Data & Perform QC (land, ice, coast, rain) flags Storm track database Generate Mean Wind Fields Storm motion North East Estimate speed & Angle (Heading Vector ) Generate Frequency of HF Occurrence per grid fields Wind Field Composite 5000km 5000km 5000km 5000km
    14. 14. Mean Wind Speed Field <ul><li>Range rings </li></ul><ul><li>1000 km increments </li></ul>kts QuikSCAT Opr ASCAT New ASCAT
    15. 15. <ul><li>Range rings </li></ul><ul><li>1000 km increments </li></ul>Hurricane Force Wind Frequency New ASCAT Opr ASCAT QuikSCAT
    16. 16. <ul><li>Range rings </li></ul><ul><li>1000 km increments </li></ul>Storm Force Wind Frequency QuikSCAT Opr ASCAT New ASCAT
    17. 17. <ul><li>Range rings </li></ul><ul><li>1000 km increments </li></ul>Gale Force Wind Frequency QuikSCAT Opr ASCAT New ASCAT
    18. 18. Summary <ul><li>ASCAT is the only data source of satellite OSVW operationally available to </li></ul><ul><li>OPC forecasters after the loss of QuikSCAT </li></ul><ul><ul><ul><li>Reliably retrieve low to moderate surface wind speeds </li></ul></ul></ul><ul><ul><ul><li>For higher wind speeds, operational ASCAT product retrievals have a low </li></ul></ul></ul><ul><ul><ul><li>wind speed bias, which increases with increasing wind speed </li></ul></ul></ul><ul><li>A new ASCAT GMF has been developed by NOAA / NESDIS to improve </li></ul><ul><li>the high wind retrievals: </li></ul><ul><ul><ul><li>High winds compare better to QuikSCAT retrievals (but still biased low) </li></ul></ul></ul><ul><ul><ul><li>Better detection of HF cyclones compared to operational ASCAT data product </li></ul></ul></ul><ul><ul><ul><li>Better representation of wind field Characteristics </li></ul></ul></ul><ul><ul><ul><li>QC flag needs tuning </li></ul></ul></ul><ul><li>Reliance on an ASCAT- only data source, will degrade the OPC warning </li></ul><ul><li>capability (specially for the dangerous HF extratropical cyclones) </li></ul><ul><ul><ul><li>Reduced coverage due to nadir gap </li></ul></ul></ul><ul><ul><ul><li>Coarser resolution </li></ul></ul></ul><ul><ul><ul><li>Low wind speed bias </li></ul></ul></ul>
    19. 19. CFRSL Group
    20. 20. Backup Slides
    21. 21. QuikSCAT Jun1999 ~ Nov 2009 <ul><li>Pencil-beam, Ku-band radar </li></ul><ul><ul><li>H-pol & V-pol </li></ul></ul><ul><li>Continuous 1800-km data swath </li></ul><ul><li>Large retrievable wind speed range </li></ul><ul><ul><li>Sensitive to rain </li></ul></ul><ul><li>Two NRT data products at 25 km & 12.5 km </li></ul>QuikSCAT mission ended on 23 Nov 2009
    22. 22. <ul><li>Fan-beam, C-band radar </li></ul><ul><ul><li>V-pol antennas </li></ul></ul><ul><li>Non-continuous 1100 km (2 x 550 km </li></ul><ul><li>with a 720 km gap) swath. </li></ul><ul><li>Wind speed low bias at high winds </li></ul><ul><li>Wind products at 50 & 25 km horizontal </li></ul><ul><li>resolutions. </li></ul>ASCAT Oct 2006 ~ present mid fore aft 37° 52° 64° 37° 27° 45° 90° 135° 64° GFS wind speed Wind speed error Operational ASCAT- QuikSCAT-GFS Wind Speeds
    23. 23. Operational ASCAT Sonde Wind Speed 28.8m/s SFMR 28 m/s ASCAT 22 m/s
    24. 24. New ASCAT Sonde Wind Speed 28.8m/s SFMR 28m/s New ASCAT 25m/s
    25. 27. The nadir gaps increase the frequency at which ASCAT data do not sample or only partially sample weather systems of interest. ASCAT QuikSCAT QuikSCAT continuous swaths provide more coverage ASCAT vs. QuikSCAT Coverage ( Oct’07 ~ May’08 )
    26. 28. ASCAT QC Flag New ASCAT QC flag needs tunning

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