Effects of Synoptic Surveillance on model forecasts for
18 July 2005 1200 UTC
Emily.


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 69 33 46 15 60193
AVNO 91121105 91306360
%IMP-32%-267%-128%-507%-410%-87%
GFNO 46 78 89122274617
GFDL 73100135190360644
%IMP-9%-28%-52%-56%-31%-4%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-39-41-74-72-27-10
AVNO-28-29-56-37-25 -3
%IMP28%29%24%49% 7%70%
GFNO 11 18 -5-15 1 -4
GFDL 16 31 -6-19 4 7
%IMP-45%-72%-20%-27%-200%-75%

Landfall forecasts

20/1200 UTC 24.8N 97.6W Near San Fernando, Mexico, 48.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 24.9697.67 49.0 19.1El Mezqital, Tamaulipas, Mexico
AVNO24.0497.70 47.5 85.0El Mezquite, Tamaulipas, Mexico
%IMP 50%-345%
GFNO23.8697.70 45.0104.9La Pesca, Tamaulipas, Mexico
GFDL23.3397.74 44.5163.9San Vicente, Tamaulipas, Mexico
%IMP -17% -56%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 18 July 2005 1200 UTC (Hurricane Emily).

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 18 July 2005 1200 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 16 July 2005 1800 UTC to 17 July 2005 1200 UTC, showing the tracks of Hurricane Emily.

Figure 4. Ensemble perturbation variance at the nominal sampling time 18 July 2005 1200 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 18 July 2005 1200 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 18 July 2005 1200 UTC. The green circles represent the dropwindsonde locations.

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 18 July 2005 1200 UTC. The green circles represent the dropwindsonde locations. [not available]

Figure 8. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 18 July 2005 1200 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 18 July 2005 1200 UTC.