Gridded TCM Update Options for Tropical Cyclone Wind Grid Guidance Richard Knabb Science and Operations Officer NOAA/NWS/NCEP/TPC/National Hurricane Center.

Gridded TCM Update Options for Tropical Cyclone Wind Grid Guidance Richard Knabb Science and Operations Officer NOAA/NWS/NCEP/TPC/National Hurricane Center

2003 Long-term Recommendations Support development work for probabilistic tropical cyclone wind grids NWS operational support structure begin to make preparations for use of probabilistic wind grids Propose changes at the December 2003 NOAA Hurricane Conference Support development work for probabilistic tropical cyclone wind grids NWS operational support structure begin to make preparations for use of probabilistic wind grids Propose changes at the December 2003 NOAA Hurricane Conference

Recent TC Wind Team Activities NOAA Hurricane Conference, Dec 2003 –Team reported on 2003 use of gridded TCM and on long term solutions –Conference recommendation to continue using “wedding cake” wind distribution in the near term, but examine other options –Recommended to extend team charter beyond January 2004 expiration Adopted new team charter in January (through January 2005) Held teleconferences in Oct, Nov, Feb NOAA Hurricane Conference, Dec 2003 –Team reported on 2003 use of gridded TCM and on long term solutions –Conference recommendation to continue using “wedding cake” wind distribution in the near term, but examine other options –Recommended to extend team charter beyond January 2004 expiration Adopted new team charter in January (through January 2005) Held teleconferences in Oct, Nov, Feb

Recent TC Wind Team Activities Changes for 2004 hurricane season –Increased cap in WFO wind grids, at 25-36 hours, from 64 to 100 kt –FSL developing TCM decoder/gridder Locally configurable and run at each WFO Addresses temporal interpolation problem Options for adding horizontal gradients between wind radii under consideration by wind team and under development by FSL Currently being evaluated by some WFOs; delivery by late spring? Will be delivered as a tool, avoiding having to wait for new release TPC gridded TCM will run in parallel, in same configuration as in 2003 Changes for 2004 hurricane season –Increased cap in WFO wind grids, at 25-36 hours, from 64 to 100 kt –FSL developing TCM decoder/gridder Locally configurable and run at each WFO Addresses temporal interpolation problem Options for adding horizontal gradients between wind radii under consideration by wind team and under development by FSL Currently being evaluated by some WFOs; delivery by late spring? Will be delivered as a tool, avoiding having to wait for new release TPC gridded TCM will run in parallel, in same configuration as in 2003

WFO Gridded Wind Speed Ranges for each TCM Forecast Period Example Max Sustained Wind = 120 kt TCM Radii WARNINGWATCH Gridded Wind Speed (kt)

Probabilistic TC Wind Grids Discussed extensively by wind team in recent meetings Currently being tested and evaluated as a Joint Hurricane Testbed (JHT) project through 2005 hurricane season Discussed extensively by wind team in recent meetings Currently being tested and evaluated as a Joint Hurricane Testbed (JHT) project through 2005 hurricane season

Monte Carlo Probability Model Knaff (CIRA/CSU) and DeMaria (NESDIS) Calculate NHC track and intensity errors (along track and cross track) from multi-year sample Determine large set of tracks and intensities (realizations) centered around official forecast by randomly sampling from error distributions Estimate wind radii distributions from errors of radii-CLIPER model Calculate probabilities by number of times specified point comes within radii of specified wind speed relative to total number of realizations –Generate probabilities of 34, 50, and 64 kt winds Run in real-time in 2003 season (starting August) Calculate NHC track and intensity errors (along track and cross track) from multi-year sample Determine large set of tracks and intensities (realizations) centered around official forecast by randomly sampling from error distributions Estimate wind radii distributions from errors of radii-CLIPER model Calculate probabilities by number of times specified point comes within radii of specified wind speed relative to total number of realizations –Generate probabilities of 34, 50, and 64 kt winds Run in real-time in 2003 season (starting August)

GFDL Hurricane Model

Questions and Discussion?

Additional Reference Slides

Definitions of Key Parameters Tropical Cyclone Intensity: Maximum sustained surface wind (1 minute average, 10 m altitude), associated with the circulation of the tropical cyclone at a given point in time. Tropical Cyclone Wind Radius: Largest distance from the center of the tropical cyclone of a particular sustained surface wind speed threshold (e.g., 34, 50, 64 kt) somewhere in a particular quadrant (NE, SE, SW, NW) surrounding the center and associated with the circulation at a given point in time. Tropical Cyclone Intensity: Maximum sustained surface wind (1 minute average, 10 m altitude), associated with the circulation of the tropical cyclone at a given point in time. Tropical Cyclone Wind Radius: Largest distance from the center of the tropical cyclone of a particular sustained surface wind speed threshold (e.g., 34, 50, 64 kt) somewhere in a particular quadrant (NE, SE, SW, NW) surrounding the center and associated with the circulation at a given point in time.

Forecast Hour Position and Intensity 12 ft seas radii 34 kt wind radii 50 kt wind radii 64 kt wind radii 3 (adv time) 12 24 36 48 72 96 120 Forecast/Advisory (TCM) New in 2003

Wind Radii Initial location, intensity, and wind radii based on all available dataInitial location, intensity, and wind radii based on all available data Wind radii forecasts based upon empirical considerations and limited objective guidanceWind radii forecasts based upon empirical considerations and limited objective guidance NHC hopes at some point to issue a 2-D analysis of a hurricane’s surface wind field, and perhaps at some point after that to issue a skillful forecast of a hurricane’s wind fieldNHC hopes at some point to issue a 2-D analysis of a hurricane’s surface wind field, and perhaps at some point after that to issue a skillful forecast of a hurricane’s wind field The current graphical display of four- quadrant radii may be misinterpreted…The current graphical display of four- quadrant radii may be misinterpreted… Initial location, intensity, and wind radii based on all available dataInitial location, intensity, and wind radii based on all available data Wind radii forecasts based upon empirical considerations and limited objective guidanceWind radii forecasts based upon empirical considerations and limited objective guidance NHC hopes at some point to issue a 2-D analysis of a hurricane’s surface wind field, and perhaps at some point after that to issue a skillful forecast of a hurricane’s wind fieldNHC hopes at some point to issue a 2-D analysis of a hurricane’s surface wind field, and perhaps at some point after that to issue a skillful forecast of a hurricane’s wind field The current graphical display of four- quadrant radii may be misinterpreted…The current graphical display of four- quadrant radii may be misinterpreted…

Isidore Limitations of Four-Quadrant Radii

Isidore Limitations of Four-Quadrant Radii NE 34 kt radius in TCM

Working Group Key Position Points TC centers are official source of TC forecastsTC centers are official source of TC forecasts WFOs have urgent need to receive TC forecasts in gridded formWFOs have urgent need to receive TC forecasts in gridded form Deterministic = Explicit or CategoricalDeterministic = Explicit or Categorical Dangers with deterministic TC winds:Dangers with deterministic TC winds: –extreme wind speeds (overreaction) –not allowing for forecast error at grid points with lesser speeds (complacency) –assumptions on storm surge and sea heights TC centers are official source of TC forecastsTC centers are official source of TC forecasts WFOs have urgent need to receive TC forecasts in gridded formWFOs have urgent need to receive TC forecasts in gridded form Deterministic = Explicit or CategoricalDeterministic = Explicit or Categorical Dangers with deterministic TC winds:Dangers with deterministic TC winds: –extreme wind speeds (overreaction) –not allowing for forecast error at grid points with lesser speeds (complacency) –assumptions on storm surge and sea heights

Short-term Recommendations (2003 Season) Gridded TCM highest priority in future AWIPS operational buildsGridded TCM highest priority in future AWIPS operational builds TC interpolation tool for GFE neededTC interpolation tool for GFE needed Mandatory disclaimers for gridded wind forecast data and any related graphical products –“Winds in and near tropical cyclones should be used with caution due to uncertainty in forecast track, size, and intensity.” Configure GFE to accommodate categorical depictions Configure text formatters to handle both explicit and categorical deterministic wind information Gridded TCM highest priority in future AWIPS operational buildsGridded TCM highest priority in future AWIPS operational builds TC interpolation tool for GFE neededTC interpolation tool for GFE needed Mandatory disclaimers for gridded wind forecast data and any related graphical products –“Winds in and near tropical cyclones should be used with caution due to uncertainty in forecast track, size, and intensity.” Configure GFE to accommodate categorical depictions Configure text formatters to handle both explicit and categorical deterministic wind information

Methodology for 2003 Hurricane Season Reference NWS Instruction 10-601 WFOs will not depict wind information at greater implied skill level than the TCM –Consistency between each WFO and their TC center –WFOs will not modify the TCM forecast track, intensity, or radii –WFOs may add mesoscale detail as necessary WFOs will use the track, intensity, and 34-, 50-, and 64-kt wind radii from the TCM as guidance Reference NWS Instruction 10-601 WFOs will not depict wind information at greater implied skill level than the TCM –Consistency between each WFO and their TC center –WFOs will not modify the TCM forecast track, intensity, or radii –WFOs may add mesoscale detail as necessary WFOs will use the track, intensity, and 34-, 50-, and 64-kt wind radii from the TCM as guidance

Gridded TCM Created 5 minutes after advisory release deadlineCreated 5 minutes after advisory release deadline Multiple TCs on single gridMultiple TCs on single grid Idealized, symmetric, cyclonic vortices represented by wind vectors on a 10 km gridIdealized, symmetric, cyclonic vortices represented by wind vectors on a 10 km grid Background (10 kt) cyclonic wind field out to 200 km beyond 34 kt radiiBackground (10 kt) cyclonic wind field out to 200 km beyond 34 kt radii Constant wind speed between radii, out to largest radii throughout each quadrantConstant wind speed between radii, out to largest radii throughout each quadrant 6 hourly from 0 to 72 hours (interpolated from 12 hourly text TCM)6 hourly from 0 to 72 hours (interpolated from 12 hourly text TCM) Created 5 minutes after advisory release deadlineCreated 5 minutes after advisory release deadline Multiple TCs on single gridMultiple TCs on single grid Idealized, symmetric, cyclonic vortices represented by wind vectors on a 10 km gridIdealized, symmetric, cyclonic vortices represented by wind vectors on a 10 km grid Background (10 kt) cyclonic wind field out to 200 km beyond 34 kt radiiBackground (10 kt) cyclonic wind field out to 200 km beyond 34 kt radii Constant wind speed between radii, out to largest radii throughout each quadrantConstant wind speed between radii, out to largest radii throughout each quadrant 6 hourly from 0 to 72 hours (interpolated from 12 hourly text TCM)6 hourly from 0 to 72 hours (interpolated from 12 hourly text TCM)

Gridded TCM AWIPS Grid 226 Domain

Additional Methodology Outside of 34 kt radii: use deterministic wind speeds from 0 to 168 hours Inside or outside of 34 kt radii: use deterministic wind direction values from 0 to 168 hours Wind gust values inside or outside of 34 kt radii: no current requirement over marine zones, little or no guidance Outside of 34 kt radii: use deterministic wind speeds from 0 to 168 hours Inside or outside of 34 kt radii: use deterministic wind direction values from 0 to 168 hours Wind gust values inside or outside of 34 kt radii: no current requirement over marine zones, little or no guidance

Example WFO Miami Wind Grids Using Gridded TCM as Guidance Gridded TCM in GFE WFO Miami Wind Grid 18 h FORECAST VALID 24 Aug/0000Z (TCM Interpolated)

Example WFO Miami Wind Grids Using Gridded TCM as Guidance 24 h FORECAST VALID 24 Aug/0600Z 25.5N 78.8W MAX WIND 115 KT...GUSTS 140 KT 50 KT... 60NE 60SE 60SW 60NW 34 KT...100NE 100SE 100SW 100NW Gridded TCM in GFE WFO Miami Wind Grid

Example WFO Miami Wind Grids Using Gridded TCM as Guidance 30 h FORECAST VALID 24 Aug/1200Z (TCM Interpolated) Gridded TCM in GFE WFO Miami Wind Grid

Example WFO Miami Wind Grids Using Gridded TCM as Guidance 36 h FORECAST VALID 24 Aug/1800Z 25.8N 81.8W MAX WIND 85 KT...GUSTS 105 KT 50 KT... 60NE 60SE 60SW 60NW 34 KT...100NE 100SE 100SW 100NW Gridded TCM in GFE WFO Miami Wind Grid

Example WFO Miami Wind Grids Using Gridded TCM as Guidance 42 h FORECAST VALID 25 Aug/0000Z (TCM Interpolated) Gridded TCM in GFE WFO Miami Wind Grid

WFO MLB Example 18 h Forecast

24 h FORECAST 24 Aug 0600 UTC Interpolating the TCM

Example WFO MLB Product/Grid Schedule Day 1 0300 UTC TCM 11:00 pm EDT Routine WFO ZFP 5:00 am EDT (0900 UTC) Day 1 3-hourly wind grids Wind Speed Cap in WFO Grids 0-24 h (12, 24) 09, 12, 15, 18 UTC Day 1 00 UTC Day 2 TC intensity 27-36 h (36) 03, 06, 09, 12 UTC Day 264 kt 39-72 h (48, 72) 15, 18, 21 UTC Day 2 00, 03, 06, 09, 12, 15, 18, 21 UTC Day 3 00 UTC Day 4 50 kt 75-120 h (no radii) 03, 06, 09, 12, 15, 18, 21 UTC Day 4 00, 03, 06, 09, 12, 15, 18, 21 UTC Day 5 00 UTC Day 6 34 kt 121-168 h (no TCM) 03, 06, 09, 12, 15, 18, 21 UTC Day 6 00, 03, 06, 09, 12, 15, 18, 21 UTC Day 7 00 UTC Day 8 30 kt

Forecasting Beyond 24 Hours Value of deterministic-only wind information, especially in explicit form, decreases rapidly –GFE not currently capable of editing categorical wind grids –IFPS 14 (July release) can provide capability to produce categorical graphics (esp. extreme winds ≥ 64 kt) via smart tools –WFO can produce graphics that include categorical winds (e.g., ≥ 64 kt, ≥ 50 kt, ≥ 34 kt) Value of deterministic-only wind information, especially in explicit form, decreases rapidly –GFE not currently capable of editing categorical wind grids –IFPS 14 (July release) can provide capability to produce categorical graphics (esp. extreme winds ≥ 64 kt) via smart tools –WFO can produce graphics that include categorical winds (e.g., ≥ 64 kt, ≥ 50 kt, ≥ 34 kt)

Example Categorical Wind Graphic

Michelle 11/02/01 00 UTC Intensity Forecast (hr: kt): 0: 55, 24: 75, 48: 90, 72: 95, 96: 70, 120: 60 0-24 hr 24-48 hr 48-72 hr CI=5% CI=2% 72-96 hr 96-120 hr 0-120 hr CI=10% CI=10% CI=10% CI=10% Experimental Probability of 64 kt Winds

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 2.At 37-72 h? 3.How far out in time can a WFO depict a tropical storm in their grids? 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 2.At 37-72 h? 3.How far out in time can a WFO depict a tropical storm in their grids? 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 3.How far out in time can a WFO depict a tropical storm in their grids? 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 3.How far out in time can a WFO depict a tropical storm in their grids? 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? In some cases they can incorrectly imply that winds of a given threshold extend to largest radius throughout a given quadrant 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? In some cases they can incorrectly imply that winds of a given threshold extend to largest radius throughout a given quadrant 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? In some cases they can incorrectly imply that winds of a given threshold extend to largest radius throughout a given quadrant 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? To account for the decreasing skill of deterministic, explicit forecasts of extreme wind speeds 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? In some cases they can incorrectly imply that winds of a given threshold extend to largest radius throughout a given quadrant 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? To account for the decreasing skill of deterministic, explicit forecasts of extreme wind speeds 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times?

ReviewReview 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? In some cases they can incorrectly imply that winds of a given threshold extend to largest radius throughout a given quadrant 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? To account for the decreasing skill of deterministic, explicit forecasts of extreme wind speeds 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 00/06/12/18 UTC Tue, 00/06/12/18 UTC Wed, 00/06/12/18 UTC Thu, 00 UTC Fri 1.What is the maximum wind speed allowable in a WFO-generated grid at 25-36 h lead time? 64 kt 2.At 37-72 h? 50 kt 3.How far out in time can a WFO depict a tropical storm in their grids? 5 days (120 h), up to 34 kt, if also in the TCM 4.What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE quadrant? 34 kt winds extend to 150 nm from the center at least somewhere in the NE quadrant 5.What is approx. average TC track error at 72 h? ~ 200 nm 6.When is the gridded TCM disseminated as compared to the text TCM? At least 5 minutes after text TCM issuance deadline 7.What temporal resolution will the gridded TCM contain in 2003? 6 hourly 8.Why are graphical representations of four-quadrant wind radii potentially misleading? In some cases they can incorrectly imply that winds of a given threshold extend to largest radius throughout a given quadrant 9.Why are maximum WFO wind speeds capped at lower values with increasing lead time? To account for the decreasing skill of deterministic, explicit forecasts of extreme wind speeds 10.A gridded TCM issued at 03 UTC Tuesday will contain grids valid at what times? 00/06/12/18 UTC Tue, 00/06/12/18 UTC Wed, 00/06/12/18 UTC Thu, 00 UTC Fri

ContributorsContributors Jack Beven, Hurricane Specialist, TPC/NHC Mark DeMaria, NOAA/NESDIS/ORA/RAMM Team James Franklin, Hurricane Specialist, TPC/NHC Jim Gross, Research Meteorologist, TPC/NHC Scott Kiser, Tropical Cyclone Program Manager, NWS Miles Lawrence, Hurricane Specialist, TPC/NHC Max Mayfield, Director, TPC/NHC Brian Motta, NWS OCWWS Training Division, COMET Branch Richard Pasch, Hurricane Specialist, TPC/NHC Ed Rappaport, Deputy Director, TPC/NHC Pablo Santos, SOO, WFO Miami David Sharp, SOO, WFO Melbourne Scott Spratt, Senior Forecaster, WFO Melbourne Stacy Stewart, Hurricane Specialist and WCM, TPC/NHC Jack Beven, Hurricane Specialist, TPC/NHC Mark DeMaria, NOAA/NESDIS/ORA/RAMM Team James Franklin, Hurricane Specialist, TPC/NHC Jim Gross, Research Meteorologist, TPC/NHC Scott Kiser, Tropical Cyclone Program Manager, NWS Miles Lawrence, Hurricane Specialist, TPC/NHC Max Mayfield, Director, TPC/NHC Brian Motta, NWS OCWWS Training Division, COMET Branch Richard Pasch, Hurricane Specialist, TPC/NHC Ed Rappaport, Deputy Director, TPC/NHC Pablo Santos, SOO, WFO Miami David Sharp, SOO, WFO Melbourne Scott Spratt, Senior Forecaster, WFO Melbourne Stacy Stewart, Hurricane Specialist and WCM, TPC/NHC

TPC/NHC Six-hour Forecast Cycle Example Time (UTC)Task / Event 00:00Synoptic time, cycle begins 00:45Receive satellite fix data 01:00Initialize models 01:20 Receive model guidance, begin preparing forecast 02:00 NWS/DOD hotline coordination call 03:00Advisory package deadline 03:15FEMA conference call 06:00Next cycle begins

TPC/NHC Tropical Cyclone Text Products Four text products issued every six hours, for active TCs, at 0300, 0900, 1500, and 2100 UTC –Forecast/Advisory (AWIPS MIATCMAT1-5, WMO WTNT21-25 KNHC) –Public Advisory (TCP) –Discussion (TCD) –Strike Probabilities (SPF) Intermediate public advisories issued every: –3 hours when watches/warnings in effect –2 hours when well-defined center tracked on radar Special advisory package issued when: –Watches and warnings required immediately –An unexpected significant change has occurred Same products and formats issued for tropical or subtropical cyclones Four text products issued every six hours, for active TCs, at 0300, 0900, 1500, and 2100 UTC –Forecast/Advisory (AWIPS MIATCMAT1-5, WMO WTNT21-25 KNHC) –Public Advisory (TCP) –Discussion (TCD) –Strike Probabilities (SPF) Intermediate public advisories issued every: –3 hours when watches/warnings in effect –2 hours when well-defined center tracked on radar Special advisory package issued when: –Watches and warnings required immediately –An unexpected significant change has occurred Same products and formats issued for tropical or subtropical cyclones

NHC OFFICIAL TRACK FORECAST ERRORS – ATLANTIC TROPICAL STORMS AND HURRICANES AVERAGE 3 DAY TRACK ERROR IS NOW ABOUT THE SAME AS THE 2 DAY ERROR WAS 20 YEARS AGO

NHC OFFICIAL WIND SPEED FORECAST ERRORS – ATLANTIC TROPICAL STORMS AND HURRICANES LITTLE OR NO IMPROVEMENT IN INTENSITY FORECASTS

Larger FLOYD (1999) Smaller ANDREW (1992) Variability in Hurricane Size

RECON FLIGHT-LEVEL WINDS HURRICANE GEORGES 9/20/98 20-23Z 105 kt 90 kt 95 kt Aircraft Reconnaissance

Visible Satellite Winds

SSM/I Wind Speed Estimates

TRMM Wind Speed Estimates

QuikSCAT Surface Wind Vectors

WSR-88D Velocity Data Lili from Lake Charles radar

H*Wind Surface Wind Analysis System Developed by Mark Powell et al. (NOAA AOML/Hurricane Research Division) Assimilates a wide variety of wind observations into a common framework Adjusts all wind data, using a boundary layer model, to 10 m, 1 min, marine exposure Allows a user to view and interpret each observation in the context of the remaining observations, and to make better judgments about the reliability of the observations Objectively analyzes a set of observations, and applies a set of algorithms (assumptions) to determine a distribution of wind in the hurricane circulation consistent with the data and those assumptions Assumes steady-state wind field during analysis period Developed by Mark Powell et al. (NOAA AOML/Hurricane Research Division) Assimilates a wide variety of wind observations into a common framework Adjusts all wind data, using a boundary layer model, to 10 m, 1 min, marine exposure Allows a user to view and interpret each observation in the context of the remaining observations, and to make better judgments about the reliability of the observations Objectively analyzes a set of observations, and applies a set of algorithms (assumptions) to determine a distribution of wind in the hurricane circulation consistent with the data and those assumptions Assumes steady-state wind field during analysis period

H*Wind Surface Wind Analysis System Provides data-dependent guidance requiring interpretation Provides an analysis, not a forecast; extrapolation along forecast track will not produce realistic forecast Current Joint Hurricane Test Bed (JHT) project to evaluate H*Wind as a guidance tool for TPC/NHC hurricane specialists in specifying current wind radii and, to a lesser extent, intensity Longer term: NHC hopes at some point to issue an analysis of a hurricane’s surface wind field, and perhaps at some point after that to issue a skillful forecast of a hurricane’s wind field. H*Wind might be the framework for the analysis, given certain software and data improvements. Provides data-dependent guidance requiring interpretation Provides an analysis, not a forecast; extrapolation along forecast track will not produce realistic forecast Current Joint Hurricane Test Bed (JHT) project to evaluate H*Wind as a guidance tool for TPC/NHC hurricane specialists in specifying current wind radii and, to a lesser extent, intensity Longer term: NHC hopes at some point to issue an analysis of a hurricane’s surface wind field, and perhaps at some point after that to issue a skillful forecast of a hurricane’s wind field. H*Wind might be the framework for the analysis, given certain software and data improvements.

Flight Level (reduced to surface) Hurricane Humberto (2001) Analysis Results Depend Strongly Upon Available Observations Flight Level and Dropsondes SFMR

Wind Radii Forecasting Empirical ideas – Is the storm strengthening or weakening? – Is persistence appropriate? – Is the storm becoming extratropical, causing wind field to expand? – Will the circulation be passing over land, such that radii could decrease? – Is the system accelerating, such that right/left asymmetries could increase? Potentially: CLIPER and dynamical models (not yet fully tested and verified) Empirical ideas – Is the storm strengthening or weakening? – Is persistence appropriate? – Is the storm becoming extratropical, causing wind field to expand? – Will the circulation be passing over land, such that radii could decrease? – Is the system accelerating, such that right/left asymmetries could increase? Potentially: CLIPER and dynamical models (not yet fully tested and verified)

GFS FORECAST OF ISIDORE FROM 9/18/02 12Z

GFS (AND NOGAPS) CORRECTLY PREDICTED THAT ISIDORE WOULD GROW CONSIDERABLY IN SIZE IN 5 DAYS

OBSERVED SEA LEVEL PRESSURE AT DAY 5

Tropical Cyclone Working Group for Populating WFO Wind Grids Initiated at the NOAA Hurricane Conference, January 2003 Vision: To populate WFO GFE and NDFD wind grids during tropical cyclone situations with the most logical and meaningful values given the uncertainty of a tropical cyclone’s structure, track, and intensity Success Criteria: Implementation of short-term solutions by all affected WFOs by June 1, 2003; report long-term solutions at the December 2003 NOAA Hurricane Conference; present long-term solutions to senior management for approval Termination Date: January 2004 Initiated at the NOAA Hurricane Conference, January 2003 Vision: To populate WFO GFE and NDFD wind grids during tropical cyclone situations with the most logical and meaningful values given the uncertainty of a tropical cyclone’s structure, track, and intensity Success Criteria: Implementation of short-term solutions by all affected WFOs by June 1, 2003; report long-term solutions at the December 2003 NOAA Hurricane Conference; present long-term solutions to senior management for approval Termination Date: January 2004

TC Working Group Mission Recommend WFO policies and procedures for representing winds associated with tropical cyclones in WFO-generated wind grids out to 120 hours. Consider wind speed and direction, including their spatial distribution Provide short-term solutions based upon current tools and guidance Propose long-term solutions by gauging the success of the short-term solutions during the 2003 season, and evaluate potential use of new tools and guidance products introduced during the 2003 season Recommend WFO policies and procedures for representing winds associated with tropical cyclones in WFO-generated wind grids out to 120 hours. Consider wind speed and direction, including their spatial distribution Provide short-term solutions based upon current tools and guidance Propose long-term solutions by gauging the success of the short-term solutions during the 2003 season, and evaluate potential use of new tools and guidance products introduced during the 2003 season

TC Working Group Members Stephanie Fauver, WFO Charleston SC Ken Haydu (backup), WFO Wilmington Tom Heffner, WFO Honolulu Scott Kiser (team lead), OS21 Steve Letro, WFO Jacksonville Jeffrey Lorens, WRH Scott Prosise, OPC Ed Rappaport, TPC/NHC Bill Sammler, WFO Wakefield Tim Schott, OS21 Dave Sharp, WFO Melbourne Bruce Terry, HPC Harvey Thurm, ERH Jamie Vavra, OS21 Ken Waters, PRH Walt Zaleski, SRH Stephanie Fauver, WFO Charleston SC Ken Haydu (backup), WFO Wilmington Tom Heffner, WFO Honolulu Scott Kiser (team lead), OS21 Steve Letro, WFO Jacksonville Jeffrey Lorens, WRH Scott Prosise, OPC Ed Rappaport, TPC/NHC Bill Sammler, WFO Wakefield Tim Schott, OS21 Dave Sharp, WFO Melbourne Bruce Terry, HPC Harvey Thurm, ERH Jamie Vavra, OS21 Ken Waters, PRH Walt Zaleski, SRH Each region, NCEP center, and Marine and Coastal Weather Services Branch (OS21) has one vote

Gridded TCM Update Options for Tropical Cyclone Wind Grid Guidance Richard Knabb Science and Operations Officer NOAA/NWS/NCEP/TPC/National Hurricane Center.

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Gridded TCM Update Options for Tropical Cyclone Wind Grid Guidance Richard Knabb Science and Operations Officer NOAA/NWS/NCEP/TPC/National Hurricane Center.

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Presentation on theme: "Gridded TCM Update Options for Tropical Cyclone Wind Grid Guidance Richard Knabb Science and Operations Officer NOAA/NWS/NCEP/TPC/National Hurricane Center."— Presentation transcript:

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