Effects of Synoptic Surveillance on model forecasts for
14 September 2005 0000 UTC
Ophelia.


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 33 67 561111894045677179011060
AVNO 35 86161288355395426421485476
%IMP-6%-28%-188%-159%-88% 2%25%41%46%55%
GFNO 35 48 51 48125245343389424590
GFDL 45 58 43 43 58100100 93124204
%IMP26%21%16%10%54%59%71%76%71%65%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-18-26-27-19-13-19-15-12 -9-11
AVNO-19-25-23-17 -7-12 -3 8 0 -1
%IMP-6% 4%15%11%46%37%80%33%100%91%
GFNO-10-21-15 1 7 5 -1 6 14 3
GFDL-12-10-12 3 6 4 7 5 10 -6
%IMP-20%52%20%-200%14%20%-500%17%29%-100%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 14 September 2005 0000 UTC (Tropical Storm Ophelia).

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 14 September 2005 0000 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 12 September 2005 0600 UTC to 13 September 2005 0000 UTC, showing the tracks of Tropical Storm Ophelia.

Figure 4. Ensemble perturbation variance at the nominal sampling time 14 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 14 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.

Figure 6. Adjoint-Derived Steering Sensitivity Vector for observations taken at the sampling time 14 September 2005 0000 UTC. The green circles represent the dropwindsonde locations.

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 14 September 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 14 September 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 14 September 2005 0000 UTC.