Pattern change to bring milder temps along with over running clouds…some light snowfall possible toward weeks end

The upper flow remains split coming off Asia. The upper jet is divided and so is the energy. To weaken the pattern further…..the short waves in the two upper flows are out of phase with each other. For the central west coast, this has the effect of creating smaller/weaker storms with less precipitation. Expect some light snowfall beginning late Thursday PM into the weekend. HPC QPF is just shy of 1/2 inch for our area through Saturday pm. (3 to 6 inches of snow?)

Longer Range:

There are some significant changes coming about during the second week of December (week-2).  A block sets up near the dateline with a negative tilt ridge importing cold arctic air via the Bering Sea into the Gulf of AK. At the present time, the mean long wave trof position is just outside of 140W, suggesting that the upper jet axis will remain to our north…. more over Northern Ca. This normally keeps the Central Sierra in the warm sector most of the time.  However, this time of the year, this could be quite a wet pattern for the Central Sierra with higher snow levels….. 7000 ft to 9,000ft?  With time…the  jet would most likely sag south into the Central Sierra. This pattern change will be the next WX topic over the following two weeks.

Just a Dweeb Observation……….

It sure has been good to see that heights have been moderately high over the Hudson Bay area so far this fall. As a result, SSTA’s are running some .5c to 3.5c in Hudson Bay. The large body of water is still unfrozen.  I believe that this is not due to global warming but due to global weather patterns.

The key height anomaly has been to this point, displaced far enough to the east to keep the wavelength somewhat excessive allowing good progression of the short wave features. Greenland Blocks that have been developing have not lasted long as the upper jet has either broken them down, or have carried off a lot of the cold Arctic air out over the Atlantic!  This is how a wet central west coast winters works best!

The Dweeber………………………:-)

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Reference Glossary of Weather Terms

Short Wave Ridging To Bring Welcome Warming This Week…..Then A Chance Of Light Snow By The Weekend


It was a cold morning in Mammoth. -5F in town and 0F at the Village.  The Coldest temps ranged from -15F to -20F in the coldest valleys early this AM.

New 12z WRF had the upper jet north/south over Eastern Ca this morning with the progs translating it eastward out of here by tonight!  That will allow the gusty winds over the crest to expire later today and temps to finally warm up over the residential sections tomorrow. However…it will be another cold day today with highs in the 20s again for The Town of Mammoth.

The Eastern Pacific Pattern is overall pretty benign for the central west coast. IE. with shortwave ridging the  next few days then a small split off system coming into California late Thursday/Friday. 

The upper jet remains pretty split coming off of  Eastern Asia. With the jet split, there tends to create an overall pattern of out of phase systems over several areas of the Pacific.  For the west coast it generally means that central west coast big storms are on hold for a while.


HPC QPF for the Central Sierra is about 1/2 inch through Saturday AM. 


Longer range:

Of note…The Dweebs are seeing something develop…..an Arctic jet at the top of the Greenland Block that will move along in the Polar Easterlies and circumnavigate the globe and eventually end up in the Gulf Of AK by Mid month. The fantasy charts blow up a monster of a storm later in the second week of Dec associated with this Cold Arctic low.  Between now and then the mean ridge position appears to be near the dateline. The wavelength suggests that the next series of strong west coast storms will be much warmer and wetter. The entrainment of tropical moisture is also a possibility.


Dr Howard and the Dweebs………………………..:-)



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Reference Glossary of Weather Terms

Snowy Saturday……Clearing Then Cold Tonight!

Snowfall began early Saturday. In fact by 7:00am there was already a dusting on the ground at the Village. Updated RFC QPF early this afternoon was back up to an inch for the Crest. So given water/snow ratios…were were back up to about 15 inches for the crest and 4 to 8 inches in town with about a foot or a bit better at the main lodge. This is certainly not a major storm, but a nice one nevertheless! It will be cold Sunday with highs in the 20s in town and single digits in the morning. The upper jet north/south over the Sierra will develop Monday. that means that it will be a blowing up upon the Sierra Crest!   

Santana’s for Southern Ca Tuesday.


An upper ridge in the mean is a bit too far west, out at the dateline for a good solid storm at the moment……that good for the Pacific NW but whimpy for the central coast….Stay Tuned!!!!!!!!!!!!!!!!!


The Dweebs have you covered!


 

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Reference Glossary of Weather Terms