Effects of Synoptic Surveillance on model forecasts for
26 August 2005 0600 UTC
Katrina.


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 75175182205222232274224323457
AVNO 67188170188229265279316413467
%IMP11%-7% 7% 8%-3%-14%-2%-41%-28%-2%
GFNO 71211307333412451483520587461
GFDL 67181290276317353395433486294
%IMP 6%14% 6%17%23%22%18%17%17%36%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-35-42-45-68-83-57-43-20-14 -6
AVNO-36-48-48-72-90-36-29-13-13 -4
%IMP-3%-14%-6%-6%-8%37%33%35% 7%33%
GFNO -1 -7 0-25-42-19 18 3 12 12
GFDL -3 -2 6-18-42-17 24 -1 9 2
%IMP-200%71%und%28% 0%11%-33%67%33%83%

Landfall forecasts

29/1110 UTC 29.3N 89.6W Near Buras, LA 77.0 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 30.5387.15 78.5272.6Pensacola, FL
AVNO30.4286.91 79.5287.5Pensacola, FL
%IMP -67% -5%
GFNO29.6584.84 79.0462.0Apalachicola, FL
GFDL30.1385.63 83.5394.0Panama City, FL
%IMP-225% 15%
29/1445 UTC 30.2N 89.6W Near LA/MS border 80.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 30.5387.15 78.5237.7Pensacola, FL
AVNO30.4286.91 79.5259.2Pensacola, FL
%IMP 45% -9%
GFNO29.6584.84 79.0462.4Apalachicola, FL
GFDL30.1385.63 83.5381.4Panama City, FL
%IMP -29% 18%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 26 August 2005 0600 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 26 August 2005 0600 UTC.

Figure 3. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 26 August 2005 0600 UTC.

Figure 4. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 26 August 2005 0600 UTC.