Weather It Is (Winter Comes Back)

 Good Evening:

Winter is returning after a short recess.

Very strong high pressure exists off the coast of Alaska, which is modifying the atmospheric circulation downstream, even as far as our area.

Due in part to uncertainty concerning the strength of the high pressure area, the global forecast models are not able to pin down what type of weather we're to expect next week.  What we do know, though, is that next few days should be rather chilly, and a period of rain is expected on Friday into Shabbat.  After a quick early week warm up, temperatures should fall off again, and an extended period of rain (or snow in the higher elevations) is likely.

Sincerely,

Barry Lynn

Weather It Is (Winter Refuses To Give Up)

 Good afternoon:

The weather pattern remains progressive and very amplified.  Hence, as we move into Shabbat and next week, rain chances will increase, but so will the unusually chilly weather for this time of year.  Rain chances should be highest during Shabbat, and then from about Thursday next week until early March.

The ensemble forecast from the European center shows greater amplification than the ensemble from the American forecasting center.  Both forecast ensembles show a chance of snow late next week and then at the end of the month (February) and early March.  These are just chances, though, and will most likely just be a cold rain.

Be well,

Barry Lynn

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