Now we’ll introduce another tool to use in your forecasting process. ASCAT (Advanced Scatterometer) wind data can help you evaluate the NWP model and potentially more accurately place weather systems.
When reading the wind barbs in the ASCAT plots, remember that they point in the direction from which the wind is blowing, and that each short barb represents 5kt, each long barb 10kt.
At the 06 UTC synoptic hour, the Polarstern is located at 53.1°S 12.6°E (the red star). The closest ASCAT pass is from the Metop-A satellite with an overpass time of 05:45 UTC. Both data swaths are to the east of the ship’s position.
ASCAT shows westerly winds of 10kt (5 m/s) immediately east of the ship’s position. At 06 UTC, the ship is also reporting a westerly wind but slightly stronger, at 12kt (6 m/s).
The southern sector of the scatterometer’s western data swath shows wind speeds greater than 10kt (5 m/s), with some directional variability indicated by the wind barbs. The southern sector of the eastern data swath also shows a distinct region of directional wind shear.