Weather It Is (Stormy Weather)

Good Afternoon:

Rainy and cold temperatures are on tap for us Friday and Shabbat.

Because of unusually cold temperatures aloft, there is the potential for thunderstorms, as well as hail.  

Our forecast shows ice pellets in the Jerusalem mountain area (but no snow).  Snow is expected in the Golan above about 1000 m.

Strong winds should accompany the trough (~50 km/h), and generally 25 to 50 mm of rain will fall from the center to the north.  Lighter rains in the northern Negev could lead to flooding in these areas.  Flooding is also expected in the Jordan Valley rivers and Dead Sea Basin.

Next, there is a hint of an even colder storm during the coming mid-week period.   There is a 60% chance that temperatures will be near freezing in the higher elevations, but only a 20% chance of substantial precipitation.  

Chilly, if not cold temperatures are forecast for the week beginning Sunday February 13th (the third week in February).

This prolonged period of more winter-like weather is associated with a persistent ridge of warmer air over western Europe or the far Eastern Atlantic Ocean.  This encourages storminess associated with a trough of low pressure in the eastern Mediterranean. As mentioned in a previous blog, this ridge is associated with an unusually strong and persistent sub-surface Pacific El-Nino superimposed on a La-Nina. The resulting wave pattern favors stormy weather in our area, especially since El-Nino has "supercharged" the subtropical Jet Stream that passes over the Mediterranean.  When that combines with the European polar jet, heavy rain storms occur.  When arctic (Siberian) air interacts with the subtropical (or even both jet streams)  snow occurs (as we experienced).

As to why this happens, here is one reference, and here is another.

Be well,

Barry Lynn