Weather It Is (Winter Weather)

  Good Afternoon:

A storm will be moving in from the west, and will linger for a few days.  

Temperatures with this storm are very cold aloft, and near freezing in the lower atmosphere (850 mb level).  Yet, at the surface we're about 1 degree Celsius too warm for seeing any snow with this storm in the central mountain region. Instead, there should be plenty of heavy rain on Monday with ice-pellets.  Ice pellets may fall heavily enough at times to make the roads a bit slippery.  But, temperatures above freezing means that the ice will melt quickly.  Winds will be unusually strong, consistent with a moderate or "near gale."  Snow is likely on the Hermon and higher peaks of the Golan.

It looks like that there will be two periods of heavy rain. One tomorrow afternoon and then late Tuesday into Wednesday morning.  Our high resolution WRF forecast is predicting generally 25 to 50 mm of rain from south central to northern Israel, with localized amounts of greater than 100 mm. Right now, the heaviest rain is forecast for the central areas, including Jerusalem.

The NAO is switching to a negative value, and this looks like this will hold until the end of the month, before a general return to positive values in January.  So, after this upcoming storm, we may be taking a week or two week break from any unusually cold weather.

Batten down you hatches or at least move items that can blow away to protected places,

Sincerely,

Barry Lynn

Weather It Is (Big Changes on the Way)

 Good Evening:

Our very pleasant late fall weather will soon become fall-past. Instead, winter will arrive with alacrity. While today many folk were out and about without jackets, that will not be the case as we move into Tuesday and even during the next two weeks. In fact, there is a twenty percent chance of snow -- based on the NCEP Global Ensemble Forecast Model (GEFS) -- sometime mid next week.  Moreover, forecasts 3 to 5 weeks out show the winter-like weather continuing.

So, what's changed?  Well, I've been under a lot of pressure about the continuing nice weather.  While people I speak to appreciate my efforts (they're having weddings, Bar Mitzvahs, or even just taking a walk outside), the nice weather just doesn't "sit right" with them.  Also, to be honest with you, it really bothers my wife, who finds herself both adding clothes and shedding clothes all within just a few hours time. Mornings are chilly, but afternoons not, and what is someone supposed to do -- bring a suitcase to work?  I mean, does one have to wear boots in the morning, but change to sandals in the afternoon?  Quite frankly, I'm not bothered at all, but the fact that my wife is bothered does bother me, if not just for the fact that she expects me to do something about it.

So, I am. 

Pulling in all of my contacts, favors, and contacting as many friends I can find, we're arranging for La Nina to be the dominant phase of the El-Nino/La-Nina oscillation (cold versus warm eastern Pacific sea surface temperatures).  For us, this means that we're more likely that the North Atlantic Oscillation will be in its positive phase   This means that an "Omega" block should persist over an extended period of time, exemplified by relatively higher pressure over Greenland and lower pressure over southern Europe and the eastern Mediterranean.  For us, this suggests a turn to colder and wetter weather.  If conditions are just right, we'll see snow here late next week in the Jerusalem mountains.  Back in December 2013, they were exceptionally "right."  But, keep in mind that when we're in a wet pattern (like we're discussing), it's usually for just rain. 

Have a good week,

Barry Lynn