Effects of Synoptic Surveillance on model forecasts for
08 July 2005 1800 UTC
Dennis.


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 80 83111135234233291242321 321
AVNO 63141125139182155207249311 356
%IMP22%-70%-13%-3%22%33%29%-3% 3% -11%
GFNO 22 80133119112 95137216358 508
GFDL 24 78118106 57 45140207330 457
%IMP-9% 2%11%11%49%53%-2% 4% 8% 10%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-28-47-86-73 -6 -3 -4 -1 -5 -1
AVNO-28-46-77-72 -3 -4 -3 -4 -7 -6
%IMP 0% 2%10% 1%50%-33%33%-300%-20%-500%
GFNO 31 15-19-29 8 3 0 2 -2 7
GFDL 29 17-26-28 5 3 0 7 -1 9
%imp 6%-13%-37% 3%37% 0% 0%-250%50%-29%

Landfall forecasts

10/1930 UTC 30.4N 87.1W Santa Rosa Island, FL, 49.5 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 29.7485.46 47.0173.9Port St. Joe, FL
AVNO29.6885.36 45.0185.5Port St. Joe, FL
%IMP -80% -7%
GFNO29.6685.41 44.5182.2Port St. Joe, FL
GFDL30.4886.16 47.0 90.5Destin, FL
%IMP 50% 50%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 08 July 2005 1800 UTC (Hurricane Dennis).

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 08 July 2005 1800 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 08 July 2005 1800 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 08 July 2005 1800 UTC.