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Targeting Strategies to Improve Hurricane and Typhoon Forecasts


NOAA/OAR Joint Hurricane Testbed, 2003-2005

Dr Sharanya J. Majumdar (UM/RSMAS/MPO)
Dr Sim D. Aberson (NOAA/AOML/HRD)
Dr Zoltan Toth (NOAA/NWS/NCEP EMC)
Dr Brian J. Etherton (UNC Charlotte)
Mr Paul Leighton (NOAA/AOML/HRD)
Mr James Franklin (NHC/NOAA/NWS/TPC)
Dr Chun-Chieh Wu (National Taiwan Univ.)


The primary purpose of operational synoptic surveillance missions (using the NOAA Gulfstream G-IV jet aircraft) is to deploy targeted GPS dropwindsondes in the environment of a tropical cyclone, to improve 1-3 day forecasts of the cyclone's track and intensity. The targeted observations are presently selected subjectively, based on the variance distribution of an ensemble forecast. The goal of our work is to develop an objective targeting strategy, entitled the Ensemble Transform Kalman Filter (ETKF), for use in improving tropical cyclone track and intensity forecasts.

In addition to testing the ETKF for Atlantic Basin tropical cyclones, it is also being examined for Northwest Pacific Basin tropical cyclones, in collaboration with Chun-Chieh Wu and the Taiwanese DOTSTAR project.

Work in Progress: ETKF targeting maps

Interpretation of these maps:

Summary Maps : maps of the vertically averaged "signal variance" within the verification region, as a function of the hypothetical observing location. NCEP (nc), ECMWF (ec) and Combined NCEP+ECMWF (co) ensembles are used.

Signal Variance evolution maps: maps of the evolution of the predicted variance of the "impact" of a hypothetical set of 9 observations, which was selected in the above summary map as the optimal observing location. Instead of these 9 "observations", flight tracks can be drawn.

2004: Northwest Pacific Basin


May 15, 16: Typhoon Nida (04W)
May 16: TS 05W
May 16: TS 06W
June 5, 6, 7: Typhoon Conson (07W)
June 16, 17: Typhoon Dianmu (09W)
June 24: Typhoon Mindulle (10W)
August 22: Typhoon Aere (20W)
September 20-23: Typhoon Meari (25W)
October 15: Typhoon Tokage (27W)
October 20: Typhoon Nock-Ten (28W)
November 29: Typhoon Nanmadol (30W)

2004: Atlantic Basin

Aug 10: Bonnie
Aug 10: Charley
Aug 15: Earl
Aug 26 - Sep 2: Frances
Sep 5-14: Ivan
Sep 15-18, 22-24: Jeanne


HRD Mission Summaries


NRL Singular Vectors

A regularly used technique for targeted observations is Singular Vectors. We are comparing our ETKF maps versus the Naval Research Laboratory's NOGAPS Singular Vectors during the 2004 season.


Joint Hurricane Testbed

58th Interdepartmental Hurricane Conference, Charleston SC, 1-5 March 2004.

HRD Synoptic Surveillance  and Ensemble Targeting groups

General Tropical Cyclone Websites:

NOAA/AOML Hurricane Research Division
HRD's Hurricane Field Program
National Hurricane Center
  NOAA/TPC Atlantic Tropical Weather Discussion
Joint Typhoon Warning Center
NRL Monterey Tropical Cyclones
CIMSS Wisconsin
Unisys Hurricane Archive