Effects of Synoptic Surveillance on model forecasts for
13 August 2005 0000 UTC
Irene.


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 38 69
AVNO 24 50
%IMP37%28%
GFNO 53117122170221276296299319343
GFDL 22 72 48 90137224249266317418
%IMP58%38%61%14738%19%16% 11% 1% -21%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-43-43
AVNO-38-42
%IMP12% 2%
GFNO 3 -7 11 -5 -4 12 7 15 29 29
GFDL 4 -8 2-18-14-10 -8 6 23 15
%IMP-33%-14%82%-260%-250%17% -14%60%21%49%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 13 August 2005 0000 UTC (Tropical Storm Irene).

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 13 August 2005 0000 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 11 August 2005 0600 UTC to 12 August 2005 0000 UTC, showing the tracks of Tropical Storm Irene.

Figure 4. Ensemble perturbation variance at the nominal sampling time 13 August 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 13 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 13 August 2005 0000 UTC. The green circles represent the dropwindsonde locations. [Not available]

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 13 August 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 13 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 13 August 2005 0000 UTC. [Not available]