Effects of Synoptic Surveillance on model forecasts for
30 August 2006 1200 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 20 44 93146228479630385
AVNO 15 36 66146187351521373
%IMP25%18%29% 0%18%27%17% 3%
GFNO 56 65 79125144381499440427
GFDL 15 44 90125187475606494501
%IMP73%32%-14% 0%-30%-25%-21%-12%-17%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN 0-20-25 3-16-18-15 -4
AVNO 0-20-25 4 -8-12-12 -5
%IMP 0% 0% 0%-67%50%33%20%-25%
GFNO 4 -6 -7 9 13 5 5 3 -3
GFDL 5 -7 -9 1-12 7 3 4 -6
%IMP-25%-17%-29%89% 8%-67%40%-33%-100%

Landfall forecasts

01/0340 UTC 33.9N 78.1W Oak Island, NC, 39.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 32.9679.48 34.5165.2Bull Bay, SC
AVNO 33.5479.07 37.0 98.2Garden City, SC
%IMP 48% 41%
GFNO 33.4779.10 39.0104.1Georgetown, SC
GFDL 33.0779.38 34.0150.2McClellanville, SC
%IMP-666% -44%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 30 August 2006 1200 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 30 August 2006 1200 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 28 August 2006 1800 UTC to 29 August 2006 1200 UTC, showing the tracks of Tropical Storm Ernesto.

Figure 4. Ensemble perturbation variance at the nominal sampling time 30 August 2006 1200 UTC from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.

Figure 5. Variance explained within the verification region (large red circle) for observations taken at the sampling time 30 August 2006 1200 UTC from the Ensemble Transform Kalman Filter run from the previous day NCEP ensemble forecast. The green circles represent the dropwindsonde locations.

Figure 6. Adjoint-Derived Steering Sensitivity Vector for observations taken at the sampling time 30 August 2006 1200 UTC. The green circles represent the dropwindsonde locations. [not available]

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 30 August 2006 1200 UTC. The green circles represent the dropwindsonde locations. [not available]

Figure 8. Initial condition differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 30 August 2006 1200 UTC. The circles represent the dropwindsonde locations.

Figure 9. 12-h forecast differences in the 850 - 200 hPa mean wind between the no and all dropwindsonde cases for 30 August 2006 1200 UTC.