Effects of Synoptic Surveillance on model forecasts for
22 August 2000 1200 UTC
DEBBY.

QuickTime movie of DLM wind model forecasts
QuickTime movie of DLM wind data increments

TRACK AND INTENSITY PERFORMANCE
TRACK (km)
MODEL	12 h	24 h	36 h	48 h	60 h	72 h	84 h	96 h	108 h	120 h

AVNN	39.	105.	43.	193.
AVAL	126.	237.	166.	100.
%IMP	-223%	-126%	-286%	48%

GFNO	39.	73.	246.	477.
GFAL	31.	63.	236.	472.
%IMP	21%	14%	4%	1%

VBNO	167.	296.	481.	691.
VBAL	164.	286.	471.	670.
%IMP	2%	3%	2%	3%
INTENSITY (kt)
MODEL	12 h	24 h	36 h	48 h	60 h	72 h	84 h	96 h	108 h	120 h

AVNN	-32.	-30.	-15.	-4.
AVAL	-23.	-29.	-10.	-7.
%IMP	28%	3%	33%	-75%

GFNO	16.	37.	46.	66.
GFAL	22.	32.	62.	78.
%IMP	-38%	14%	-35%	-18%

SHNO	2.	8.	30.	43.
SHAL	2.	7.	28.	41.
%IMP	0%	13%	7%	5%

DSNO	2.	8.	30.	43.
DSAL	2.	7.	28.	41.
%IMP	0%	13%	7%	5%

Landfall forecasts

22/1500 UTC 18.5N 64.4W near Virgin Gorda 3 h into the forecast
MODEL LAT LON TIME ERROR LOCATION

AVNN 18.39 64.68 4.5 31.9 West End, Tortola, British Virgin Islands
AVAL 18.52 64.57 2.5 18.0 East End, Tortola, British Virgin Islands
%IMP 67% 44%

GFNO 18.50 64.49 3.5 9.5 East End, Tortola, British Virgin Islands
GFAL 18.47 64.65 4.5 26.6 Rough Point, Tortola, British Virgin Islands
%IMP -200% -180%

VBNO 18.44 64.57 7.5 19.1 East End, Tortola, British Virgin Islands
VBAL 18.54 64.54 7.5 15.4 East End, Tortola, British Virgin Islands
%IMP 0% 19%

Landfall forecasts

22/1500 UTC 18.5N 64.4W near Virgin Gorda	3 h into the forecast
MODEL	LAT	LON	TIME	ERROR	LOCATION

AVNN	18.39	64.68	4.5	31.9 West End, Tortola, British Virgin Islands
AVAL	18.52	64.57	2.5	18.0 East End, Tortola, British Virgin Islands
%IMP			67%	44%

GFNO	18.50	64.49	3.5	9.5 East End, Tortola, British Virgin Islands
GFAL	18.47	64.65	4.5	26.6 Rough Point, Tortola, British Virgin Islands
%IMP			-200%	-180%

VBNO	18.44	64.57	7.5	19.1 East End, Tortola, British Virgin Islands
VBAL	18.54	64.54	7.5	15.4 East End, Tortola, British Virgin Islands
%IMP			0%	19%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 22 August 2000 1200 UTC (Hurricane Debby).

Figure 2. Track forecasts for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the AVN, GFDL, and VBAR models initialized on 22 August 2000 1200 UTC. The best track is shown in black.

Effects of Synoptic Surveillance on model forecasts for
22 August 2000 1200 UTC
DEBBY.

TRACK AND INTENSITY PERFORMANCE

Landfall forecasts

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 22 August 2000 1200 UTC (Hurricane Debby).

Figure 2. Track forecasts for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the AVN, GFDL, and VBAR models initialized on 22 August 2000 1200 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 August 2000 1200 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 22 August 2000 1200 UTC.

Effects of Synoptic Surveillance on model forecasts for 22 August 2000 1200 UTC DEBBY.

TRACK AND INTENSITY PERFORMANCE

Landfall forecasts

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 22 August 2000 1200 UTC (Hurricane Debby).

Figure 2. Track forecasts for the no dropwindsonde (NO or NN) and the all dropwindsonde (AL) runs for the AVN, GFDL, and VBAR models initialized on 22 August 2000 1200 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 August 2000 1200 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 22 August 2000 1200 UTC.

Effects of Synoptic Surveillance on model forecasts for
22 August 2000 1200 UTC
DEBBY.