Effects of Synoptic Surveillance on model forecasts for
11 June 2005 0000 UTC
Arlene.


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 89160343474535610
AVNO 40 58 66111231312
%IMP55%64%81%77%57% 49%
GFNO 10 96205296338223
GFDL 24 61177256302229
%IMP-140%35%14%14%14%-3%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-29 -8 -7-10-11-15
AVNO-26 -1 -5-10 -9-13
%IMP10%87%29% 0%18%13%
GFNO 4 12 -2 3 3 33
GFDL 2 9 -1 6 4 30
%IMP50% 75%50%-100%-67% 9%

Landfall forecasts

11/1900 UTC 30.3N 87.5W Near and just west of Pensacola 19.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 30.2388.08 25.5 56.2Dauphin Island, AL
AVNO30.5787.15 21.5 45.0Pensacola, FL
%IMP 62% 20%
GFNO30.3788.13 20.5 60.9Dauphin Island, AL
GFDL30.2387.72 18.5 22.5Gulf Shores, AL
%IMP 67% 63%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 11 June 2005 0000 UTC (Tropical Storm Arlene).

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 11 June 2005 0000 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 08 June 2005 0600 UTC to 09 June 2005 0000 UTC, showing the tracks of Tropical Storm Arlene.

Figure 4. Ensemble perturbation variance at the nominal sampling time 11 June 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 11 June 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 11 June 2005 0000 UTC. The green circles represent the dropwindsonde locations.

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 11 June 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 11 June 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 11 June 2005 0000 UTC.