Effects of Synoptic Surveillance on model forecasts for
30 August 2006 1800 UTC
Ernesto.


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 11 22 52 99170238354215180
AVNO 15 29 35132178293368167107
%IMP-36%-32%33%-33%-5%-23%-4%22%41%
GFNO 11 28 14 63 97100168135352
GFDL 0 24 78 99135286303167241
%IMP100%14%-457%-57%-39%-186%-80%-24%32%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN -9-24-14 -8-16-22 -9 -7-13
AVNO -8-24-13 -2-14-12 -9 -9-13
%IMP11% 0% 7%75%13%45% 0%-29% 0%
GFNO -3-12 3 13 0-14 19 3 -9
GFDL -4-10 -6 12 -3 -4 22 0-11
%IMP-33%17%-100% 8%und%71%-16%100%-22%

Landfall forecasts

01/0340 UTC 33.9N 78.1W Oak Island, NC, 33.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 33.8678.57 31.5 43.6North Myrtle Beach, SC
AVNO 33.9178.51 32.5 37.8Sunset Beach, NC
%IMP 44% 13%
GFNO 33.8678.25 32.5 14.5Long Beach, NC
GFDL 33.6878.81 30.5 70.0Myrtle Beach, SC
%IMP-160%-383%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 30 August 2006 1800 UTC (Tropical Storm Ernesto).

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 30 August 2006 1800 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 30 August 2006 1800 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 30 August 2006 1800 UTC.