Effects of Synoptic Surveillance on model forecasts for
22 September 2002 0600 UTC
Isidore.


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
AVNN39.109.239.301.370.476.501.654.795.1070.
AVNO39.142.261.278.357.483.564.725.1079.1410.
%IMP0%-30%-9%8%4%-1%-13%-11%-36%-32%
GFNO38.49.68.76.106.275.335.509.713.1003.
GFAL33.70.94.94.162.359.523.775.1044.1366.
%IMP13%-43%-38%-24%-53%-31%-56%-52%-46%-36%
AVNN-76.-34.-12.-3.1.1.-8.-9.2.24.
AVNO-59.-19.-1.3.-2.3.4.4.26.36.
%IMP22%44%92%0%-100%-200%50%56%-1200%-50%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
GFNO-24.25.34.43.48.71.63.68.79.95.
GFAL-16.27.39.41.36.43.33.29.44.73.
%IMP25%-8%-15%5%25%29%48%57%44%23%
SHNO4.49.71.76.71.68.60.57.68.82.
SHIP3.48.73.80.78.76.68.64.73.87.
%IMP25%2%-3%-5%-10%-12%-13%-12%-7%-6%
DSNO4.49.71.76.71.68.60.57.68.82.
DSHP3.48.73.80.78.76.68.64.73.87.
%IMP25%2%-3%-5%-10%-12%-13%-12%-7%-6%

Landfall forecasts

22/2100 UTC 21.3N 89.3W Puerto Telchac, Yucatan, Mexico 15 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN21.1490.4423.5119.4 Sisal, Yucatan, Mexico
AVAL21.3890.2719.5100.8 Near Sisal, Yucatan, Mexico
%IMP47%16%
GFNO21.3889.0418.028.3 Dzilam de Bravo, Yucatan, Mexico
GFAL21.3689.1620.515.9 Puerto Telchac, Yucatan, Mexico
%IMP-83%44%
26/0600 UTC 29.1N 90.3W Just west of Grand Isle, LA 96 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNNNo landfall forecast
AVALNo landfall forecast
%IMP
GFNONo landfall forecast
GFALNo landfall forecast
%IMP

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 22 September 2002 0600 UTC (Hurricane Isidore).

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 22 September 2002 0600 UTC. The best track is shown in black.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 22 September 2002 0600 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 22 September 2002 0600 UTC.