Effects of Synoptic Surveillance on model forecasts for
29 August 2006 0600 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 23 45 54 73 66115145186204
AVNO 65 75 91 71 97139183268410
%IMP-183%-67%-69% 3%-47%-21%-26%-44%-101%
GFNO 63 35 15 29 76162240491586464
GFDL 70 59 95 90109173229430551393
%IMP-11%-69%-533%-210%-43%-7% 5%12% 6%15%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-13 -8 -5-11-25-17 -9-18-17
AVNO-14-11 -7-10-26-15 -7-15-11
%IMP-8%-38%-40% 9%-4%12%22%17%35%
GFNO 8 10 25 16 9 -3-13 18 4 14
GFDL 9 11 19 18 2 -6-14 11 4 10
%IMP-13%-1i0%24%-13%78%-100%-8%39% 0%-40%

Landfall forecasts

30/0300 UTC 24.9N 80.6W Plantation Key, FL, 21 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 24.7780.99 22.0 41.9Duck Key, FL
AVNO 24.6881.30 22.0 74.7Big Pine Key, FL
%IMP 0% -78%
GFNO 24.7980.80 22.5 23.6Layton, FL
GFDL 24.7380.96 23.5 40.9Marathon, FL
%IMP-67% -73%
30/0500 UTC 25.2N 80.7W Southwestern Miami-Dade County, FL, 23 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 25.2681.20 26.0 50.7Flamingo, FL
AVNO 24.6881.30 22.0 83.6Big Pine Key, FL
%IMP 33% -65%
GFNO 25.1480.95 25.0 26.0Flamingo, FL
GFDL 25.1681.21 26.5 51.5Flamingo, FL
%IMP-75% -98%
01/0340 UTC 33.9N 78.1W Oak Island, NC, 69.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 33.0279.45 66.5158.8McClellanville, SC
AVNO 32.7779.96 63.5213.5Charleston, SC
%IMP -92% -34%
GFNO 33.0379.50 62.0213.5McClellanville, SC
GFDL 32.5380.17 60.5245.3Edisto Beach, SC
%IMP -19% -15%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 29 August 2006 0600 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 29 August 2006 0600 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 29 August 2006 0600 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 29 August 2006 0600 UTC.