Another Major Surge of Moisture into Mammoth today then Hose to Shift South into Southern Ca Monday into Wednesday…..more snow for Mammoth through Mid Week

Satellite imagery shows a strong short wave trof about 700mi west of the crest moving toward the Northern California coast. This system is associated with the cold vortex and northern branch of the upper jet . As it intersects with the fire hose coming  in from north of Hawaii, another excessive period of snowfall is expected over the Southern and Central Sierra today. AMSU PWV are once again near 1.5 inches. The OAK sounding showing saturation for much of the column and is -22within the dendritic growth zone.

Bishop reported heavy rain mid morning with some power outages report as well in both Mono and Inyo counties.

Today and into tonight will be the heaviest snowfall for Mammoth. As the latest storm moves in to the Sierra, precipitation will focus along the entire length of the Sierra. Up-slope conditions are ideal with 700-MB winds from the southwest in the range of 45 to 65Knots. Add dynamics and you have periods of 2 to 4 inches an hour snowfalls. Expect this extremely heavy snow falls through early evening……then the intensity should slowly decrease as the cold front moves south. 

Snow levels will be falling later today and into tonight behind the front. 

The heaviest precipitation shifts southward into Southern Ca Monday…however, plenty of snowfall is still likely for the Mono County Sierra early to middle of next week.


Another 7 to 9 feet is possible between 4:00am Sunday through Tuesday over the sierra crest. The Village at  of Mammoth could see another 2 to 3 feet by Midnight tonight .

The Dweeber…………………..:-)

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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.

Snowfall Rates To Increase Again tonight! The Night of Lights should be Spectactular!

So far….snowfall amounts ranged from 5 feet over the crest to 2 to 3 feet near the village. Snowfall to increase again tonight!

Today’s WX pattern is consistent with yesterday. Upper ridge continues over the dateline with weak tropical  low to the south near 22n-179w spinning up moisture. This pattern continues to advect moisture northward from west of Hawaii then NE toward the west coast. The deep vortex over Gulf of AK has now moved SSE to off the Oregon coast. The upper westerly flow is consoladating at the base of the upper low. Meanwhile subtropical moisture is being pulled eastward and as it approaches the west coast it is being energized by the upper jet.

Latest AMSU TPW shows a even higher moisture content within the river with peak values 1.5 to 1.6 inches now.  

Looking at the the NAM 12 Time Height Sections off the 18z Run, ( http://weather.utah.edu/index.php?t=nam212&r=MSA&d=ET#)  UVM was at low ebb over Mammoth Mt. today. DVM will continue until about 7:00pm (03z) then increase into the night. Plenty of deep moisture with this system…..way up to 300mb. Snowfall rates will increase again after 7:00pm…with peak UVM about 15z Sunday. (7:00AM) Plenty of Upward Vertical Motion exists through Sunday afternoon in the saturated air mass. Expecting another 2 to 4 feet at the village by Sunday night.

The cold front will move toward the state early Sunday and reach the coast during the morning.  FROPA for Mammoth should be about 02z Monday. (6:00pm Sunday) The max precip will be from Central Ca south toward Southern Ca.  

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


Potential Bluebird Morning……. December 22nd!


——————————————————————————–
Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.

Snow Now Falling In Mammoth

Snowfall began at 3:00am this morning and is now expected to continue for several days. No surprises this morning with QPF on track. Updated HPC 5 day amounts for the south central sierra is up to 14 inches over the period along the west side and 9 to 10 inches over the crest. This means that Mammoth MT is likely to receive a good 10 to 12 feet in the coming 5 days. (10:1 ratio)

The Town of Mammoth 4 to 6 feet. It still appears that for the most part, it will all be snow for the town. There are several waves within the subtropical fetch now currently connected to the central coast. Periods of strong vertical motion will coincide with heavier snowfall rates. Moisture Flux Divergence within the flow is expected to be extreme.

As far as the models go over the next 3 or 4 days…..the large upper low in the gulf of Alaska will remain pretty much stationary with a swift zonal flow underneath that system. The upper jet at 160knots stretches from 160w to the west coast just south of 40 north. The little eddies or impulses that streak across the zonal flow are enhanced areas of vertical motion and represent potential heavier areas of precip when they move on shore.

Looking at the CIRA TPW loop from AMSU  http://amsu.cira.colostate.edu/TPW/global.htm You can see the juice up to 35 to 40 mm within the stream . A subtropical upper low near 30 north- 175 west is keeping the pump juiced.

Analogs:

There has been some talk around town of this being a pineapple connection. A pattern similar to February 1986.  This is not true. The February 16 through 19th event was a true pineapple connection.

The analog shows that a blocking high became cut off over Alaska while the typical upper jet diverged to the right and dug back an upper trof that became confluent with the subtropical jet which road over a subtropical ridge into California. The 500mb heights over Mammoth went as high as 570dm and we had 6 to 7 inches of rain over a heavy snow pack. That was the winter that the Sherwin’s slid.

This system is totally different. Instead of high pressure in the northern Gulf of AK, there is a  deep vortex.  The blocking high is out near the dateline in a quasi REX configuration. Check out the analog at http://vortex.plymouth.edu/reanal-u.html then compare to current 3 day means.

Better analogs are 1968 11/28; 1971 11-28; 1961 12/22 and 1966 11/29



The Dweeber………………………:-)

——————————————————————————–
Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.