a. FY12-13 GIMPAP Project Proposal Title Pageversion 26 October 2011

Title: Developing GOES-Based Tropical Cyclone Recurvature Tools

Status: New

Duration: 2 years

Project Leads:

John Knaff NESDIS/StAR –RAMMB John.Knaff@noaa.gov

Mark DeMaria NESDIS/StAR–RAMMB Mark.DeMaria@noaa.gov

Other Participants:

Andrea Schumacher CIRA/CSU

Ed Fukada USN/Joint Typhoon Warning Center

Chris Landsea NOAA/National Hurricane Center

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b. Project Summary

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Construct a GOES-based product that estimates the short-term (0-48 hours) timing of TC recurvature for • North Atlantic and • Northwest Pacific TC basins

Where the point of recurvature is defined by the point along the track at which the meridional motion is poleward and the zonal component of motion changes from westward to eastward.

By making uses of • GOES/MTSAT water vapor imagery• GFS analysis/forecast fields• Tropical cyclone databases

and by combining/leveraging objective and subjective methods described in Hodanish and Gray (1993) and Dvorak (1995), respectively

c. Motivation / Justification• Supports NOAA’s Mission and its Weather and Water

strategic goal• Improved tropical cyclone track forecasts are a top

NOAA/DOD priority. • Late Guidance: The most recent numerical track

guidance is not available when the track forecasts are produced

• Track changes are discrete in nature. • These short-term accelerations can be very important

when tropical cyclones are affecting land areas. • The most difficult track forecasts often involve the timing

of recurving tropical cyclones (TCs).

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Positions (aircraft-based center locations )

Six-hourly best track positions

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Hurricane Earl (2010)

d. Methodology

• Combine three data types (based on 2 older studies)– Tropical cyclone tracks/locations – Information in the GOES/GMS/MTSAT water vapor

imagery (2001-2010) (cf. Dvorak (1995))• Patterns associated with mid-latitude troughs• Distance from a tropical cyclone• Speed of the storm and approach of the trough

– Information from the GFS/NCEP Reanalysis (cf. Hodanish and Gray (1993))• Distance and direction of the westerly upper-level winds from

the TC center• Depth of the upper-level westerlies• Forecasts of these fields 5

Dvorak (1995)

Subjective Technique Water Vapor Imagery

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Cur

ved

Moi

stur

e Ba

nd (C

MB)

1000 km (9o Latitude)

Example: Hurricane Bill (2009)

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Hodanish and Gray (1993)

• Recurvature is preceded by increases in or occurrence of

1. 500 and 200-hPa zonal winds within 600 to 800 km west, northwest and north of the TC

2. 200-hPa meridional winds within 600 to 800 km northwest and north of the TC

• An index constructed from these factors is related to the point of recurvature.

• Real-timeTesting in the West Pacific showed promise

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Basic findings :

Brief Description of the Method

• Determine what upper-level wind conditions are required for TC recurvature using historical data

• Determine the relationships between upper-level winds (500-200 hPa) and water vapor imagery in historical TC recurvature events using common statistical techniques and assuming a perfect prog solution. (such information can augment the first few hours of the GFS forecasts when the model forecasts are 3-6 hours old)

• Use GFS (or any other forecast model) forecasts and the water vapor imagery to produce probabilistic forecasts the timing of TC recurvature through 48 hours.

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e. Expected Outcomes

• A GOES product that produces a probabilistic forecast of the timing of TC recurvature.

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e. Possible Path to Operations

• If successful, GOES PSDI funding will be sought for implementation in operations.

• Alternatively, this product could seek Joint Hurricane Testbed funding for transition.

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f. Milestones (FY12)

• Compile historical TC recurvature cases for Atlantic and West Pacific from the best tracks

• Construct the storm relative WV data for those cases

• Construct the NCEP reanalysis storm relative wind fields for those cases

• Begin exploring the statistical relationships between the wind fields and water vapor features

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f. Milestones (FY13)

• Develop statistical relationships between the wind, water vapor features and the timing of recurvature in the storm relative framework

• Develop probabilistic model for the timing of TC recurvature

• Test the model on independent data.

• Document in refereed journal

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g. Funding Request (K)

Funding Sources Procurement OfficePurchase Items FY12 FY13

GIMPAP StARTotal Project Funding 54K 57K

StARGrant to CIRA 49K 51K

StARFederal Travel 5K 3K

StAR Federal Publication 3K

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g. Spending Plan FY12

• FY12 $54,000 Total Project Budget1. Total Grant to CIRA - $ 49K

– 40% FTE (CIRA Research Scientist) $ 47K– CIRA Travel - $ 2 K

2. Federal Travel - $ 5K– Visit to the Joint Typhoon Warning Center, and NRL, Monterey (September 2012)

for collaboration/feedback

3. Federal Publication Charges – $ 0K4. Federal equipment - $ 0K5. Transfer to other agencies - $ 0K 6. Other - $ 0K

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g. Spending Plan FY13

• FY13 $57,000 Total Project Budget

1. Total Grant to CIRA $ 51K– 40% FTE (CIRA Research Scientist) $ 49K– CIRA Travel - $ 2 K

2. Federal Travel • Trip to NRLMRY

Monterey CA

June 2013 $ 3KorTrip to JTWC, Pearl Harbor, HI

3. Federal Publication Charges – $ 3K

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