Effects of Synoptic Surveillance on model forecasts for
20 September 2005 0000 UTC
Rita.


Quicktime movie of AVN DLM wind model forecast
Quicktime movie of DLM wind data increment


TRACK AND INTENSITY PERFORMANCE

TRACK (km)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN 23 30 45115248350426441430470
AVNO 56 54 72139259321360387398407
%IMP-143%-80%-60%-21%-4% 8%15%12% 7%13%
GFNO 30 24 22 94193234269293316346
GFDL 33 32 40145251305373395413439
%IMP-10%-33%-82%-54%-30%-30%-39%-35%-31%-27%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-41-63-89-117-104-81-73-59-18 9
AVNO-31-55-78-102 -91-69-66-53-13 11
%IMP21%12%12%13%12%15%10%10%28%-22%
GFNO 37 18 6-33-32-19-19-11-14 -5
GFDL 25 15 5-37-29 -8-15-12-16 -5
%IMP32%17%17%-12% 9%58%21%-9%-14% 0%

Landfall forecasts

24/0730 UTC 29.7N 93.7W between Johnson's Bayou, LA, and Sabine Pass 103.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 28.6196.38117.5286.8Port O'Connor, TX
AVNO28.6595.98116.0250.1Matagorda, TX
%IMP 11% 13%
GFNO28.5896.07 96.5261.5Matagorda, TX
GFDL28.1097.00 96.0377.0Rockport, TX
%IMP -7% -44%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 20 September 2005 0000 UTC (Tropical Storm Rita).

Figure 2. Track forecasts for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the AVN and GFDL models initialized on 20 September 2005 0000 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 18 September 2005 0600 UTC to 19 September 2005 0000 UTC, showing the tracks of Tropical Storm Rita.

Figure 4. Ensemble perturbation variance at the nominal sampling time 20 September 2005 0000 UTC from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.

Figure 5. Variance explained within the verification region (large red circle) for observations taken at the sampling time 20 September 2005 0000 UTC from the Ensemble Transform Kalman Filter run from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations. [not available]

Figure 6. Adjoint-Derived Steering Sensitivity Vector for observations taken at the sampling time 20 September 2005 0000 UTC. The green circles represent the dropwindsonde locations.

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 20 September 2005 0000 UTC. The green circles represent the dropwindsonde locations.

Figure 8. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 20 September 2005 0000 UTC. The circles represent the dropwindsonde locations.

Figure 9. 24-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 20 September 2005 0000 UTC.