Effects of Synoptic Surveillance on model forecasts for
20 September 2005 1200 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 70 35 56151206271378400488463
AVNO 35 0 32105132202267333430530
%IMP50%100%43%30%36%25%29%17%12%-14%
GFNO 63 73 56122146181198203324466
GFDL 38 38 24 82112159178256440657
%IMP40%48%51%33%23%12%10%-26%-36%-41%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-59-82-111-98-74-67-58-12 20 14
AVNO-46-71 -99-85-56-47-23 15 44 20
%IMP22%13%11%13%24%30%60%-25%-120%-43%
GFNO-17-19-41-29-15-14 -5 29 14 0
GFDL-12-14-42-31-15-16 -9 16 5 0
%IMP29%26%-2%-7% 0%-14%-80%45%64%100%

Landfall forecasts

24/0730 UTC 29.7N 93.7W between Johnson's Bayou, LA, and Sabine Pass 91.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 29.5594.35115.0 64.9High Island, TX
AVNO29.2395.03110.5138.8Galveston, TX
%IMP 19%-114%
GFNO28.9295.25 95.5173.4Freeport, TX
GFDL28.7495.71 92.0222.2Matagorda, TX
%IMP 87% -28%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 20 September 2005 1200 UTC (Hurricane 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 1200 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 18 September 2005 1800 UTC to 19 September 2005 1200 UTC, showing the tracks of Hurricane Rita.

Figure 4. Ensemble perturbation variance at the nominal sampling time 20 September 2005 1200 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 1200 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 1200 UTC. The green circles represent the dropwindsonde locations.

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 20 September 2005 1200 UTC. The green circles represent the dropwindsonde locations. [not available]

Figure 8. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 20 September 2005 1200 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 1200 UTC.