Effects of Synoptic Surveillance on model forecasts for
31 August 2006 0000 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 35 37 90194373472198122
AVNO 24 30 62174328448234212
%IMP33%19%31%40%12% 5%-18%-74%
GFNO 36 44 45119304473301213
GFDL 38 78 22 77187430325308
%IMP-6%-77%51%35%38% 9%-8%-45%
INTENSITY (kt)
MODEL12 h24 h36 h48 h60 h72 h84 h96 h108 h120 h
AVNN-18-20 8-13-20-11 2 -9
AVNO-17-21 12 -5-11-12 1 -6
%IMP 6%-5%-50%62%45%-9%50%33%
GFNO-11 -9 15 11 -1 12 12 2
GFDL-13-12 28 19 -6 20 8 3
%IMP-18%-33%-87%-73%-500%-67%-33%-50%

Landfall forecasts

01/0340 UTC 33.9N 78.1W Oak Island, NC, 27.75 h into the forecast
MODELLATLONTIMEERRORLOCATION
AVNN 33.8678.61 26.5 47.3North Myrtle Beach, SC
AVNO 33.9278.48 23.0 35.1Sunset Beach, NC
%IMP-280% 26%
GFNO 33.9478.24 28.5 13.7Long Beach, NC
GFDL 34.2077.82 30.5 42.1Wilmington, NC
%IMP-267%-107%

Figure 1. NCEP 850 - 200 hPa mean wind analysis for 31 August 2006 0000 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 31 August 2006 0000 UTC.

Figure 3. NCEP Global Ensemble Prediction System track forecasts for all cyclones in the Atlantic basin initialized from 29 August 2006 0600 UTC to 30 August 2006 0000 UTC, showing the tracks of Tropical Storm Ernesto.

Figure 4. Ensemble perturbation variance at the nominal sampling time 31 August 2006 0000 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 31 August 2006 0000 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 31 August 2006 0000 UTC. The green circles represent the dropwindsonde locations. [not available]

Figure 7. NOGAPS Singular Vector for observations taken at the sampling time 31 August 2006 0000 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 31 August 2006 0000 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 31 August 2006 0000 UTC.