Using ASCAT Wind and Other Data in Marine Forecasting

4.0 Forecast Future Conditions at a Projected Point » 4.6 Compare Model to Polarstern and ASCAT Data

Now we’re at the final stage where we need to evaluate whether the GFS model is suitable to be used for the forecast. The table shows that although the model is underestimating the MSLP slightly, the wind speed and direction are accurate. All of this data is valid for the Polarstern’s location at 53.1°S and 12.6°E.

Parameter

GFS

Polarstern

ASCAT

Lat/lon

53.1°S/12.6°E

53.1°S/12.6°E

53.1°S/12.6°E

Wind speed

10-15kt

12kt

not covered by satellite pass

Wind direction

NW

260°

not covered by satellite pass

MSLP

994 hPa

998.5 hPa

not covered by satellite pass

In terms placing the cold front, we can use the GFS wind plot showing the cold front for evaluation. It appears that the model is placing the cold front farther to the east than where the western boundary of the cloud band on the IR 10.8 µm image is depicting it. Earlier, we noted the possible reasons for this discrepancy.

GFS 10m wind field over South Atlantic on 6 UTC 23 Nov 2013 with location of cold front and ship's position labeled

Comparing the ASCAT and model winds and model MSLP in the tabs, it appears that the model is placing the cold front accurately. For these reasons, we can be reasonably confident in using the GFS model to forecast the likely locations, movement, weather, and marine parameters associated with the cold front for the upcoming 24-hour period.