Effects of Synoptic Surveillance on model forecasts for
28 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 85 92 60 60 58 67114213284403
AVNO 63 0 15 30 37 44 71 78104121
%IMP26%100%75%50%36%34%38%73%63%70%
GFNO 76 46 37 11 67107165188193190
GFDL108 60 70 69131182256275367506
%IMP-42%-30%-89%-527%-96%-70%-5%-46%-90%-166%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN -7 -7 -6 -5-14-28-18 1 -1 18
AVNO -3 -9 -6 -2-12-27-17 8 10 14
%IMP57%-29% 0%60%14% 4% 6%-700%-900%22%
GFNO 0 8 13 19 14 27 34 5 -5-11
GFDL 6 19 25 21 21 15 27 -1-20 17
%IMPund%-138%-92%-11%-50%44%21%80%-300%-55%

Landfall forecasts

30/0300 UTC 24.9N 80.6W Plantation Key, FL, 33 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 25.6080.30 36.0 83.4Perrine, FL
AVNO 24.8480.75 33.0 16.5Layton, FL
%IMP100% 80%
GFNO 25.0480.47 35.5116.3Tavernier, FL
GFDL 24.8880.70 37.5 10.3Islamorada, FL
%IMP-80% 91%
30/0500 UTC 25.2N 80.7W Southwestern Miami-Dade County, FL, 35 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 25.6080.30 36.0 59.9Perrine, FL
AVNO 25.2780.92 36.5 23.4Flamingo, FL
%IMP-50% 61%
GFNO 25.2380.56 37.0 14.5Florida City, FL
GFDL 25.1380.82 39.5 15.2Flamingo, FL
%IMP-125% -5%
01/0340 UTC 33.9N 78.1W Oak Island, NC, 81.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 34.5276.50 91.5162.3Atlantic Beach, NC
AVNO 33.1479.11 78.0126.0Georgetown, SC
%IMP 62% 22%
GFNO 33.3079.22 83.5123.2Georgetown, SC
GFDL 32.5980.25 81.5247.2Edisto Beach, SC
%IMP 86%-101%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 28 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 28 August 2006 1800 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 28 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 28 August 2006 1800 UTC.