Effects of Synoptic Surveillance on model forecasts for
23 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 45 56 93189238431
AVNO 0 33102225306546
%IMP 0%41%-10%-19%-29%-27%
GFNO 39 97150321443691
GFDL 45118155298426689
%IMP-15%-22%-3% 7% 4% 0%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-54-33-10 -4 -6 -5
AVNO-29-12 5 10 5 -4
%IMP46%64%50%-250%17%20%
GFNO -4 6 38 21 18 2
GFDL 0 4 34 26 22 2
%IMP100%33%11%-24%-22% 0%

Landfall forecasts

24/0730 UTC 29.7N 93.7W between Johnson's Bayou, LA, and High Island 31.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 29.5894.32 35.0 61.3High Island, TX
AVNO29.6094.30 36.0 59.0High Island, TX
%IMP -29% 4%
GFNO29.2994.89 35.0123.8Galveston, TX
GFDL29.3194.78 37.0113.1Galveston, TX
%IMP -57% 9%

Figure 1. NCEP 850 - 230 hPa mean wind analysis for 23 September 2005 0000 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 23 September 2005 0000 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 21 September 2005 0600 UTC to 22 September 2005 0000 UTC, showing the tracks of Hurricane Rita.

Figure 4. Ensemble perturbation variance at the nominal sampling time 23 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 23 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 23 September 2005 0000 UTC. The green circles represent the dropwindsonde locations.

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 23 September 2005 0000 UTC. The green circles represent the dropwindsonde locations.

Figure 8. Initial condition differences in the 850 - 230 hPa mean wind between the no and all dropwindsonde cases for 23 September 2005 0000 UTC. The circles represent the dropwindsonde locations.

Figure 9. 24-h forecast differences in the 850 - 230 hPa mean wind between the no and all dropwindsonde cases for 23 September 2005 0000 UTC.