Thursday, December 01, 2016

Extended High Wind Event At Whipple Observatory

Photo showing the entrance gate to the Whipple Observatory on Mt. Hopkins. The large structure at the top of Mt. Hopkins is the MMT facility, and the nearby weather station is the Mt. Hopkins RAWS site, which often observes extreme wind speeds from the east.

I am exploring ways to forecast the high wind events at the observatory, with Mike Leuthold's help. Mike is extracting forecast soundings for Sonoita from his WRF forecasts. The location, along Highway 83 just north of Sonoita, is directly upwind of the massif of the Santa Ritas Sky Island. Shown here are skewT forecasts from the 06 UTC run of the WRF-GFS last night - top is valid at 5:00 pm on Saturday, December 3rd, and the bottom is valid at midnight that night on the 4th. Deep easterly flow impacts the Sky Island beginning during the early am hours on the 3rd and reach maximum speeds during Saturday night. 

The skewT speeds of 40 kt, and a bit higher, below mountain top indicate that wind speeds at the RAWS station could exceed 70 to 80 mph during this extended event - assuming of course that the forecasts are accurate this far out. This WRF forecast cycle provides an excellent case for examining how far ahead of an event the model can be used to forecast same.

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