Effects of Synoptic Surveillance on model forecasts for
28 August 2005 1800 UTC
Katrina.

Quicktime movie of AVN DLM wind model forecast
Quicktime movie of DLM wind data increment

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	24	22	56	52	34
AVNO	11	44	94	54	153
%IMP	54%	-100%	-68%	-4%	-350%

GFNO	31	59	58	52	198
GFDL	20	53	29	78	176
%IMP	35%	10%	50%	-50%	11%
INTENSITY (kt)
MODEL	12 h	24 h	36 h	48 h	60 h	72 h	84 h	96 h	108 h	120 h

AVNN	-56	-10	-13	-13	-3
AVNO	-21	-16	-13	-10	-3
%IMP	62%	-60%	0%	23%	0%

GFNO	16	32	-11	-2	25
GFDL	10	29	-13	0	28
%IMP	37%	9%	-18%	100%	-12%

Landfall forecasts

29/1110 UTC 29.3N 89.6W Near Buras, LA 17.0 h into the forecast
MODEL LAT LON TIME ERROR LOCATION

AVNN 29.30 89.77 17.5 16.5 Grand Isle, LA
AVNO 29.45 89.88 18.0 31.8 Grand Isle, LA
%IMP -100% -93%

GFNO 29.49 89.94 19.0 39.1 Grand Isle, LA
GFDL 29.47 90.00 18.5 43.1 Grand Isle, LA
%IMP 25% -10%

29/1445 UTC 30.2N 89.6W Near LA/MS border 20.75 h into the forecast
MODEL LAT LON TIME ERROR LOCATION

AVNN 29.30 89.77 17.5 101.3 Grand Isle, LA
AVNO 29.45 89.88 18.0 87.6 Grand Isle, LA
%IMP 15% 14%

GFNO 29.49 89.94 19.0 85.4 Grand Isle, LA
GFDL 29.47 90.00 18.5 89.8 Grand Isle, LA
%IMP -29% -5%

Landfall forecasts
29/1110 UTC 29.3N 89.6W Near Buras, LA 17.0 h into the forecast
MODEL	LAT	LON	TIME	ERROR	LOCATION

AVNN	29.30	89.77	17.5	16.5	Grand Isle, LA
AVNO	29.45	89.88	18.0	31.8	Grand Isle, LA
%IMP			-100%	-93%

GFNO	29.49	89.94	19.0	39.1	Grand Isle, LA
GFDL	29.47	90.00	18.5	43.1	Grand Isle, LA
%IMP			25%	-10%

29/1445 UTC 30.2N 89.6W Near LA/MS border 20.75 h into the forecast
MODEL	LAT	LON	TIME	ERROR	LOCATION

AVNN	29.30	89.77	17.5	101.3	Grand Isle, LA
AVNO	29.45	89.88	18.0	87.6	Grand Isle, LA
%IMP			15%	14%

GFNO	29.49	89.94	19.0	85.4	Grand Isle, LA
GFDL	29.47	90.00	18.5	89.8	Grand Isle, LA
%IMP			-29%	-5%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 28 August 2005 1800 UTC (Hurricane Katrina).

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 2005 1800 UTC.

Effects of Synoptic Surveillance on model forecasts for
28 August 2005 1800 UTC
Katrina.

TRACK AND INTENSITY PERFORMANCE

Landfall forecasts

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 28 August 2005 1800 UTC (Hurricane Katrina).

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 2005 1800 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 28 August 2005 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 2005 1800 UTC.

Effects of Synoptic Surveillance on model forecasts for 28 August 2005 1800 UTC Katrina.

TRACK AND INTENSITY PERFORMANCE

Landfall forecasts

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 28 August 2005 1800 UTC (Hurricane Katrina).

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 2005 1800 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 28 August 2005 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 2005 1800 UTC.

Effects of Synoptic Surveillance on model forecasts for
28 August 2005 1800 UTC
Katrina.