Effects of Synoptic Surveillance on model forecasts for
29 August 2005 0000 UTC
Katrina.


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 39108104 82
AVNO 29 44 49 62
%IMP26%59%53%24%
GFNO 51129134166
GFDL 35 78 21110
%IMP31%40%84%34%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-25-11 -7-14
AVNO-17-13 -7-12
%IMP32%-18% 0%14%
GFNO 30 19 -6 -6
GFDL 6 17 -3 0
%IMP80%11%50%100%

Landfall forecasts

29/1110 UTC 29.3N 89.6W Near Buras, LA 11.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 29.3189.82 12.5 21.3Grand Isle, LA
AVNO29.5089.90 12.0 36.6Grand Isle, LA
%IMP 33% 72%
GFNO29.2990.01 12.5 39.7Grand Isle, LA
GFDL29.3089.69 12.5 8.7Grand Isle, LA
%IMP 0% 78%
29/1445 UTC 30.2N 89.6W Near LA/MS border 14.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 29.2990.01 12.5108.6Grand Isle, LA
AVNO29.5089.90 12.0 83.0Grand Isle, LA
%IMP 22% 24%
GFNO29.4989.94 12.5 85.8Grand Isle, LA
GFDL29.3089.69 12.5100.4Grand Isle, LA
%IMP 0%-17%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 29 August 2005 0000 UTC (Hurricane Katrina).

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 29 August 2005 0000 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 27 August 2005 0600 UTC to 28 August 2005 0000 UTC, showing the tracks of Hurricane Katrina.

Figure 4.

Figure 5. Variance explained within the verification region (large red circle) for observations taken at the sampling time 29 August 2005 0000 UTC from the Ensemble Transform Kalman Filter run from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.

Figure 6. Adjoint-Derived Steering Sensitivity Vector for observations taken at the sampling time 29 August 2005 0000 UTC. The green circles represent the dropwindsonde locations.

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 29 August 2005 0000 UTC. The green circles represent the dropwindsonde locations. [none available]

Figure 8. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 29 August 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 29 August 2005 0000 UTC.