gridded tcm update options for tropical cyclone wind grid guidance richard knabb science and...

Gridded TCM UpdateGridded TCM Update

Options for Tropical Cyclone Wind Grid GuidanceOptions for Tropical Cyclone Wind Grid Guidance

Gridded TCM UpdateGridded TCM Update

Options for Tropical Cyclone Wind Grid GuidanceOptions for Tropical Cyclone Wind Grid Guidance

Richard KnabbRichard Knabb

Science and Operations OfficerScience and Operations Officer

NOAA/NWS/NCEP/TPC/National Hurricane CenterNOAA/NWS/NCEP/TPC/National Hurricane Center

2003 Long-term Recommendations2003 Long-term Recommendations2003 Long-term Recommendations2003 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 ActivitiesRecent TC Wind Team ActivitiesRecent TC Wind Team ActivitiesRecent 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 ActivitiesRecent TC Wind Team ActivitiesRecent TC Wind Team ActivitiesRecent 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

0

20

40

60

80

100

120

0-24 25-36 37-72 73-120 121-168

Forecast Period (h)

64 kt

50 kt

34 kt

none

WFO Gridded Wind Speed RangesWFO Gridded Wind Speed Rangesfor each TCM Forecast Periodfor each TCM Forecast Period

WFO Gridded Wind Speed RangesWFO Gridded Wind Speed Rangesfor each TCM Forecast Periodfor each TCM Forecast Period

Example Max Sustained Wind = 120 ktExample Max Sustained Wind = 120 ktTCM RadiiTCM Radii

WARNING WATCH

Gri

dd

ed W

ind

Sp

eed

(kt

)

Probabilistic TC Wind GridsProbabilistic TC Wind GridsProbabilistic TC Wind GridsProbabilistic 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 ModelMonte Carlo Probability ModelKnaff (CIRA/CSU) and DeMaria (NESDIS)Knaff (CIRA/CSU) and DeMaria (NESDIS)Monte Carlo Probability ModelMonte Carlo Probability Model

Knaff (CIRA/CSU) and DeMaria (NESDIS)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 ModelGFDL Hurricane ModelGFDL Hurricane ModelGFDL Hurricane Model

Questions and Discussion?Questions and Discussion?Questions and Discussion?Questions and Discussion?

Additional Reference SlidesAdditional Reference SlidesAdditional Reference SlidesAdditional Reference Slides

Definitions of Key ParametersDefinitions of Key ParametersDefinitions of Key ParametersDefinitions 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 Forecast HourHour

Position Position and and

IntensityIntensity

12 ft 12 ft seas seas radiiradii

34 kt 34 kt wind wind radiiradii



33 (adv time)(adv time)

1212

2424

3636

4848

7272

9696

120120

Forecast/Advisory (TCM)Forecast/Advisory (TCM)Forecast/Advisory (TCM)Forecast/Advisory (TCM)

New inNew in

20032003

Wind RadiiWind RadiiWind RadiiWind Radii

• Initial location, intensity, and wind radii based Initial location, intensity, and wind radii based on all available dataon all available data

• Wind radii forecasts based upon empirical Wind radii forecasts based upon empirical considerations and limited objective guidanceconsiderations and limited objective guidance

• NHC hopes at some point to issue a 2-D NHC hopes at some point to issue a 2-D analysisanalysis of a hurricane’s surface wind field, and of a hurricane’s surface wind field, and perhaps at some point after that to issue a perhaps at some point after that to issue a skillful skillful forecastforecast of a hurricane’s wind field of a hurricane’s wind field

• The current graphical display of four-quadrant The current graphical display of four-quadrant radii may be misinterpreted…radii may be misinterpreted…

• Initial location, intensity, and wind radii based Initial location, intensity, and wind radii based on all available dataon all available data

• Wind radii forecasts based upon empirical Wind radii forecasts based upon empirical considerations and limited objective guidanceconsiderations and limited objective guidance

• NHC hopes at some point to issue a 2-D NHC hopes at some point to issue a 2-D analysisanalysis of a hurricane’s surface wind field, and of a hurricane’s surface wind field, and perhaps at some point after that to issue a perhaps at some point after that to issue a skillful skillful forecastforecast of a hurricane’s wind field of a hurricane’s wind field

• The current graphical display of four-quadrant The current graphical display of four-quadrant radii may be misinterpreted…radii may be misinterpreted…

Isidore

Limitations of Four-Quadrant RadiiLimitations of Four-Quadrant RadiiLimitations of Four-Quadrant RadiiLimitations of Four-Quadrant Radii

Isidore

Limitations of Four-Quadrant RadiiLimitations of Four-Quadrant RadiiLimitations of Four-Quadrant RadiiLimitations of Four-Quadrant Radii

NE 34 kt radius in TCM

Working Group Key Position PointsWorking Group Key Position PointsWorking Group Key Position PointsWorking 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 WFOs have urgent need to receive TC forecasts in gridded formforecasts in gridded form

• Deterministic = Explicit or CategoricalDeterministic = Explicit or Categorical

• Dangers with deterministic TC winds:Dangers with deterministic TC winds:– extreme wind speeds (overreaction)extreme wind speeds (overreaction)– not allowing for forecast error at grid not allowing for forecast error at grid

points with lesser speeds (complacency)points with lesser speeds (complacency)– assumptions on storm surge and sea assumptions on storm surge and sea

heightsheights

• TC centers are official source of TC forecastsTC centers are official source of TC forecasts

• WFOs have urgent need to receive TC WFOs have urgent need to receive TC forecasts in gridded formforecasts in gridded form

• Deterministic = Explicit or CategoricalDeterministic = Explicit or Categorical

• Dangers with deterministic TC winds:Dangers with deterministic TC winds:– extreme wind speeds (overreaction)extreme wind speeds (overreaction)– not allowing for forecast error at grid not allowing for forecast error at grid

points with lesser speeds (complacency)points with lesser speeds (complacency)– assumptions on storm surge and sea assumptions on storm surge and sea

heightsheights

Short-term RecommendationsShort-term Recommendations(2003 Season)(2003 Season)

Short-term RecommendationsShort-term Recommendations(2003 Season)(2003 Season)

• Gridded TCM highest priority in future AWIPS Gridded TCM highest priority in future AWIPS operational buildsoperational 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 Gridded TCM highest priority in future AWIPS operational buildsoperational 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 forMethodology for2003 Hurricane Season2003 Hurricane Season

Methodology forMethodology for2003 Hurricane Season2003 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 TCMGridded TCMGridded TCMGridded TCM• Created 5 minutes after advisory release Created 5 minutes after advisory release

deadlinedeadline• Multiple TCs on single gridMultiple TCs on single grid• Idealized, symmetric, cyclonic vortices Idealized, symmetric, cyclonic vortices

represented by wind vectors on a 10 km gridrepresented by wind vectors on a 10 km grid• Background (10 kt) cyclonic wind field out to Background (10 kt) cyclonic wind field out to

200 km beyond 34 kt radii200 km beyond 34 kt radii• Constant wind speed between radii, out to Constant wind speed between radii, out to

largest radii throughout each quadrantlargest radii throughout each quadrant• 6 hourly from 0 to 72 hours (interpolated 6 hourly from 0 to 72 hours (interpolated

from 12 hourly text TCM)from 12 hourly text TCM)

• Created 5 minutes after advisory release Created 5 minutes after advisory release deadlinedeadline

• Multiple TCs on single gridMultiple TCs on single grid• Idealized, symmetric, cyclonic vortices Idealized, symmetric, cyclonic vortices

represented by wind vectors on a 10 km gridrepresented by wind vectors on a 10 km grid• Background (10 kt) cyclonic wind field out to Background (10 kt) cyclonic wind field out to

200 km beyond 34 kt radii200 km beyond 34 kt radii• Constant wind speed between radii, out to Constant wind speed between radii, out to

largest radii throughout each quadrantlargest radii throughout each quadrant• 6 hourly from 0 to 72 hours (interpolated 6 hourly from 0 to 72 hours (interpolated

from 12 hourly text TCM)from 12 hourly text TCM)

Gridded TCMGridded TCMGridded TCMGridded TCM

AWIPS Grid 226 DomainAWIPS Grid 226 DomainAWIPS Grid 226 DomainAWIPS Grid 226 Domain

Additional MethodologyAdditional MethodologyAdditional MethodologyAdditional 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 GridsExample WFO Miami Wind GridsUsing Gridded TCM as GuidanceUsing Gridded TCM as GuidanceExample WFO Miami Wind GridsExample WFO Miami Wind GridsUsing Gridded TCM as GuidanceUsing Gridded TCM as Guidance

Gridded TCM in GFEGridded TCM in GFEGridded TCM in GFEGridded TCM in GFE WFO Miami Wind GridWFO Miami Wind GridWFO Miami Wind GridWFO Miami Wind Grid

18 h FORECAST VALID 24 Aug/0000Z18 h FORECAST VALID 24 Aug/0000Z(TCM Interpolated)(TCM Interpolated)



24 h FORECAST VALID 24 Aug/0600Z24 h FORECAST VALID 24 Aug/0600Z25.5N 78.8W MAX WIND 115 KT...GUSTS 140 KT25.5N 78.8W MAX WIND 115 KT...GUSTS 140 KT

50 KT... 60NE 60SE 60SW 60NW 34 KT...100NE 100SE 100SW 100NW50 KT... 60NE 60SE 60SW 60NW 34 KT...100NE 100SE 100SW 100NW




WFO MLBWFO MLBExampleExample


18 h 18 h ForecastForecast


24 h 24 h FORECASTFORECAST

24 Aug24 Aug

0600 UTC0600 UTC

InterpolatingInterpolating

the TCMthe TCM


24 Aug24 Aug

0700 UTC0700 UTC


the TCMthe TCM


24 Aug24 Aug

0800 UTC0800 UTC


the TCMthe TCM


24 Aug24 Aug

0900 UTC0900 UTC


the TCMthe TCM


24 Aug24 Aug

1000 UTC1000 UTC


the TCMthe TCM


24 Aug24 Aug

1100 UTC1100 UTC


the TCMthe TCM


24 Aug24 Aug

1200 UTC1200 UTC


the TCMthe TCM


24 Aug24 Aug

1300 UTC1300 UTC


the TCMthe TCM


24 Aug24 Aug

1400 UTC1400 UTC


the TCMthe TCM


24 Aug24 Aug

1500 UTC1500 UTC


the TCMthe TCM


24 Aug24 Aug

1600 UTC1600 UTC


the TCMthe TCM


24 Aug24 Aug

1700 UTC1700 UTC


the TCMthe TCM


24 Aug24 Aug

1800 UTC1800 UTC


the TCMthe TCM


24 Aug24 Aug

1900 UTC1900 UTC


the TCMthe TCM


24 Aug24 Aug

2000 UTC2000 UTC


the TCMthe TCM


24 Aug24 Aug

2100 UTC2100 UTC


the TCMthe TCM


24 Aug24 Aug

2200 UTC2200 UTC


the TCMthe TCM


24 Aug24 Aug

2300 UTC2300 UTC


the TCMthe TCM


25 Aug25 Aug

0000 UTC0000 UTC


the TCMthe TCM

Example WFO MLB Product/Grid ScheduleExample WFO MLB Product/Grid ScheduleExample WFO MLB Product/Grid ScheduleExample WFO MLB Product/Grid ScheduleDay 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 2 64 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 HoursForecasting Beyond 24 HoursForecasting Beyond 24 HoursForecasting 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 GraphicExample Categorical Wind GraphicExample Categorical Wind GraphicExample 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 WindsExperimental Probability of 64 kt WindsExperimental Probability of 64 kt WindsExperimental Probability of 64 kt Winds

ReviewReviewReviewReview1. 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?








grid at 25-36 h lead time? 64 kt2. At 37-72 h?3. How far out in time can a WFO depict a tropical storm in their grids?







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?








grid at 25-36 h lead time? 64 kt2. At 37-72 h? 50 kt3. How far out in time can a WFO depict a tropical storm in their grids?








2. At 37-72 h? 50 kt3. 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 TCM4. What is meant in the TCM by a 34 kt wind radius of 150 nm in the NE

quadrant?









quadrant?









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 nm6. When is the gridded TCM disseminated as compared to the text



















TCM? At least 5 minutes after text TCM issuance deadline7. What temporal resolution will the gridded TCM contain in 2003?



















6 hourly8. Why are graphical representations of four-quadrant wind radii

potentially misleading?










potentially misleading?










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










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

ContributorsContributorsContributorsContributorsJack 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-hourTPC/NHC Six-hourForecast Cycle ExampleForecast Cycle Example

TPC/NHC Six-hourTPC/NHC Six-hourForecast Cycle ExampleForecast Cycle Example

Time (UTC) Task / Event00:00 Synoptic time, cycle begins

00:45 Receive satellite fix data

01:00 Initialize models

01:20Receive model guidance, begin preparing forecast

02:00NWS/DOD hotline coordination call

03:00 Advisory package deadline

03:15 FEMA conference call

06:00 Next cycle begins

TPC/NHC Tropical CycloneTPC/NHC Tropical CycloneText ProductsText Products

TPC/NHC Tropical CycloneTPC/NHC Tropical CycloneText ProductsText 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 – ATLANTICTROPICAL STORMS AND HURRICANES

AVERAGE 3 DAY TRACK ERROR IS NOW ABOUT THE SAME AS THE 2 DAY ERROR WAS 20 YEARS AGO

5

10

15

20

25

30

year

err

or

(kn

ots

)

72-hour48-hour24-hour

NHC OFFICIAL WIND SPEED FORECAST ERRORS – ATLANTICTROPICAL STORMS AND HURRICANES

LITTLE OR NO IMPROVEMENT IN INTENSITY FORECASTS

LargerFLOYD (1999)

SmallerANDREW (1992)

Variability in Hurricane SizeVariability in Hurricane SizeVariability in Hurricane SizeVariability in Hurricane Size

RECON FLIGHT-LEVEL WINDS

HURRICANE GEORGES 9/20/98 20-23Z

105 kt

90 kt

90 kt95 kt

Aircraft ReconnaissanceAircraft ReconnaissanceAircraft ReconnaissanceAircraft Reconnaissance

Visible Satellite WindsVisible Satellite WindsVisible Satellite WindsVisible Satellite Winds

SSM/I Wind Speed EstimatesSSM/I Wind Speed EstimatesSSM/I Wind Speed EstimatesSSM/I Wind Speed Estimates

TRMM Wind Speed EstimatesTRMM Wind Speed EstimatesTRMM Wind Speed EstimatesTRMM Wind Speed Estimates

QuikSCAT Surface Wind VectorsQuikSCAT Surface Wind VectorsQuikSCAT Surface Wind VectorsQuikSCAT Surface Wind Vectors

WSR-88D Velocity DataWSR-88D Velocity DataWSR-88D Velocity DataWSR-88D Velocity Data

Lili from Lake Charles radarLili from Lake Charles radarLili from Lake Charles radarLili from Lake Charles radar

H*Wind Surface WindH*Wind Surface WindAnalysis SystemAnalysis 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



• 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 LevelFlight Level(reduced to (reduced to

surface)surface)

Hurricane Humberto (2001)Hurricane Humberto (2001)

Analysis Results Depend StronglyAnalysis Results Depend StronglyUpon Available ObservationsUpon Available Observations

Analysis Results Depend StronglyAnalysis Results Depend StronglyUpon Available ObservationsUpon Available Observations

Flight Level andFlight Level andDropsondesDropsondes

Flight Level andFlight Level andSFMRSFMR

Wind Radii ForecastingWind Radii ForecastingWind Radii ForecastingWind 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 Tropical Cyclone Working Group for Populating WFO Wind GridsPopulating WFO Wind Grids

Tropical Cyclone Working Group for Tropical Cyclone Working Group for Populating WFO Wind GridsPopulating 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 MissionTC Working Group MissionTC Working Group MissionTC 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 MembersTC Working Group MembersTC Working Group MembersTC Working Group MembersStephanie 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

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...

Documents

tropical cyclone wind

wfo wind grids

maximum sustained surface

hurricanes surface wind

wedding cake wind distribution

errors of radii

use of gridded tcm

given point