Weather It Is (Snow More Likely Today)

Good Morning:

The latest global ensemble data (GEFS) shows that temperatures aloft are forecast to be about 1 degree colder than the forecast from yesterday.  Moreover, lower atmospheric temperatures are also forecast to be colder than though yesterday.  Temperatures at 850 mb in the central mountains should be about -2 C, while at 700 mb the temperatures should be about -12.5 C.  At 500 mb, temperatures are forecast to be about -29 C.

The difference is enough to up the relative amounts of snow compared to graupel and rain.  Based on a high-resolution WRF forecast based in the Department of Earth Sciences at the Hebrew University of Jerusalem, Givat Ram) liquid equivalent amounts of snow should be between 3-5 mm in Gush Etzion and 1-3 mm in Jerusalem. Up to 5 to 10 mm of liquid equivalent ice is possible in Gush Etzion, with 3 - 5 mm in Jerusalem.   Moreover, the change over to a mixture of snow, ice, and rain should occur by late morning, with the heaviest snow in the afternoon and evening hours.

I wrote "liquid equivalent," rather than snow accumulation (in centimeters) because surface temperatures will probably be too warm for snow to "stick," except on possibly cars or other cold surfaces.  There is normally about 10 to 1 ratio between snow amounts and liquid equivalent amounts.

We'll probably come close to seeing snow accumulate, but not close enough.  Still, roads could become slippery in heavier ice/snow interludes.

As for Friday's storm: there is a 25% chance of a significant snow (based on the European Ensemble forecast from late evening yesterday).

Barry Lynn