2/10/03F.Marks1 Development of a Tropical Cyclone Rain Forecasting Tool Frank D. Marks NOAA/AOML,...

2/10/03 F.Marks 1

Development of a Tropical Cyclone Rain Forecasting Tool

Frank D. MarksNOAA/AOML, Hurricane Research Division, Miami, FL 33149

QPE Techniques in TCs• TRMM and gauges

QPF Techniques in TCs• R-CLIPER• 2002 Storms• Where do we go from here?

Support from NOAA JHT and NASA TRMM and CAMEX

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DATA: TMI R estimates for 245 storms (December

1997-2000), globally, yielding 2121 events, from TD to CAT5 (Lonfat et al 2003).

1998-2000 TMI events by IntensityStorm Intensity Events %TD/TS 1361 64Category 1-2 548 26Category 3-5 212 10Total 2121

560,000 hourly gauge estimates in 46 US landfalling hurricanes (1948-2000) (DeMaria 2003)

QPE techniques in TCs:

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Develop R-CLIPER from gauge and TMI climatology for operational and model QPF comparisons.

Project R-climatology along NHC forecast track.

QPF techniques in TCs:

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R-CLIPER Radial distribution of R for gauge and TMI

climatology consistent. TMI peak R increases with intensity: 3 mm h-1

TD/TS; 7.2 mm h-1 CAT 1-2; 12.5 mm h-1 CAT 3-5. TMI peak R radius decreases with storm intensity.

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color contours denote

Rtotal (inches, peak at landfall listed)

Position and

intensity from best track (6

h)

R-CLIPER Cases

7.7”

4.8” 15.9”

4.1” 8.6”

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Andrew 92

Danny 97

Floyd 99

Allison 01

R-CLIPER underestimates area of Rtotal by factor of 2 using CDF.

R-CLIPER Cases

20%

50%

90%

PMM R-CLIPER/Gauge Rtotal

50%

90%

% of gauges

% of area

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QPF in Landfalling TCs For 2002 season ran 584 forecasts in 32

storms in the ATL, EPAC, and CPAC for both the gauge and TRMM R-CLIPER.

0

20

40

60

80

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

summary

ATLEPACCPAC

Nu

mb

er

of

Fo

rec

as

ts

Storm

Atlantic 14 255

East Pacific 15 281

Central Pacific

3 48

Total 32 584

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QPF in Landfalling TCs

GaugeTRMM

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Where do we go from here?

R-CLIPER ran operationally in 2002 at NHC.

Provides benchmark for evaluation of other QPF techniques.

Develop data products for hurricane specialists.

Compare R-CLIPER forecasts to models and 6-h average rainfall amounts on HPC 1°X1° grid.

Work with HPC to provide track guidance after landfall.

RCLIPER

RCLIPER Rmax along track, with a probability of heavy rain right or left of track.

RCLIPER Rmax increases when storm slows or turns.

Model shows symmetry and asymmetry.

Comparison with Models Rogers et al 2002

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QPF in Landfalling TCsISSUES: Are we providing our users what they need?

Different users have different needs. How do we develop an evaluation/validation

system for high-resolution QPF product?How will it be used operationally

(probabilistic)?NEEDS: New products developed for forecasters and

hydrologists. New display products to convey uncertainty to

forecaster and others.