Storms 17 thru 26 DEC

[donbrown]

mammothweather.com

An active weather pattern is expected to continue for the next week. However, there are still a few more parts of the current pattern to keep the weather unsettled through the weekend.

Here are the WX players both today and through the weekend:

1. The weather for today Thursday will be highlighted by an exiting upper low at 700mb that will wrap some moisture back into the sierra this afternoon and evening bringing the possibility of some light snowfall later today.

2. The next piece of energy from the remains of the current pattern comes into California late Friday afternoon. Although the main energy slips to the south, well to the west of the Sierra Crest, there may be some light snow or snow showers from it.

3. There appears to be a break in the action Saturday before an elongated flat ridge builds east into California. The ridge is so flat that a pretty good chunk of moisture comes over it in a northwest flow….and may give some light ”warm advection” type snowfall to our area Saturday night and into Sunday. So as you can see, the weekend is expected to be unsettled. However the Dweebs do not expect heavy amounts of snowfall.

4. Stronger short wave ridging is expected Sunday night through Monday morning with the clouds on the increase again Monday afternoon with a more significant storm Monday Night into Tuesday 18-19 DEC. The new Thursday 12z GFS has a good moisture tap from the subtropics for the Monday Night/Tuesday system and has plenty of “UVM“ upward vertical motion, for a foot of heavy snow or better for storm 18-19 DEC. The Freezing Level with this system will be higher than the last.

Fantasyland 20-26 DEC: (Best guess at this time; using only today’s GFS Deterministic Guidance…..Highly Subject to Change)

5. The Dweebs see yet another storm with strong UVM slamming the Central Sierra Wednesday night into Thursday after which the pattern goes into transition to give us possibly a few days break before a new weather type develops. Although the Dweebs see some kind of system for Christmas eve/day……it appears that there will be one more multi-day storm that will be the “Grand Finale”, beginning the 26th and ending that following Friday 28 DEC. Again, this is not for planning purposes…..just for fun!



Dr Howard and the Dweebs………………………

 

[donbrown]

Storms measured in feet more likely 22-to-26 December

 

[donbrown]

www.mammothweather.com

The next significant system for late Monday/Tuesday/Ngt 17-18 DEC has a “good” subtropical tap so it will begin warmer with snow levels rising to about 7000 feet Monday PM. The freezing level will then be falling to 3000 feet by Tuesday night. As an estimate….It looks to be between a 1 to 2 footer at this time for the upper elevations above 8000 feet by midnight Tuesday. Will fine tune snowfall forecast amounts over the weekend…..

There will be a break Wednesday through at least Thursday. The 12z GFS was slowing the next weather system slowing down until later in the weekend. The Dweebs believe that the models do not have a good handle on the timing of this next storm for the end of next week yet. However, it looks very potent, slow moving and includes “The Possibility” of a tropical connection for the Central West Coast and thus a lot of precipitation.21-23 DEC.


By the end of next weekend…..the Dweebs have noted that the GFS deterministic run this morning has indicated quite a bit of tropical convection developing SSW of the Hawaiian Islands. Additionally….About Christmas Eve, there seems to be a Kona Storm developing to the NW of Kauai with the entrainment of a lot of Tropical Moisture as well. So Hawaii may be in for a lot of rain over the Holiday!

If the pattern REX’es up along 165W between Christmas and New Years, we will have to keep a weary-eye out for a more significant “AR” event for the west coast. A lot will depend upon if indeed the subtropical system develops, pineapple express of moisture to the west coast ... not sure where 26-31 december and how it phases with the northern branch with time. At this time, it is unclear what part of the west coast would be effected.

 

[donbrown]

Storm Thurs 20 DEC to 23 Dec to bring 2-4 feet at 7000 feet ... mammoth area.

Amazing day after X-mas storm is still possible.

 

[donbrown]

Today 18 DEC Winter Storm to Impact Lincoln & Mohave Counties Today: LINCOLN COUNTY - Winter Storm Warning in effect from 6 AM to 6 PM PST. Snowfall of 5-10 expected above 4500�. MOHAVE COUNTY - Winter Weather Advisory in effect from 2 PM to 11 PM MST. Snowfall of 3-6� above 5000� with lesser amounts above 4000� is expected. For more info visit: http://goo.gl/phXDu. Potential Impacts: Hazardous winter driving conditions are possible on area roadways including Interstate 40, US-95, US-66, NV-319, NV-322

Storm 20-23 DEC to bring couple inches as low as 500 feet in Shasta County.

A Gulf of Alaska storm system will move into Northern California coast late Wednesday into Thursday. This moist system could initially interact with the trapped cold air pockets at the low elevations and generate snow at the valley floor levels, especially for the Shasta Lake and Northern Sacramento Valley region. The overall weather pattern taking shape for interior Northern California points toward a long duration precipitation event with heavy snow piling up in the mountains and low elevation valley rain. Travelers will want to plan ahead and anticipate adverse weather conditions developing by later this week.

Shasta County will possibly have a few inches of snow Wednesday night into Thursday morning down 500 feet.

 

[donbrown]

NOAA 18 December 3PM PST

A Major snow storm is forecast to hit interior northern California Thursday through Sunday 20-23 DEC.

Three to more than 6 feet of snow is forecast over the mountains through the four-day period.

Snow levels will be much lower in the Shasta County mountains�down to around 500 feet on Thursday before rising to above 3000 feet during the weekend. This means heavy snowfall along Interstate 5 is likely with possible accumulations of 1 to 3 feet.

The mountain valleys of Plumas County will also experience snow�with 1 to 2 feet possible in the Chester and Quincy areas.

Along the Interstate 80 and Highway 50 corridor�4 to 5 feet of snow is forecast�with higher amounts possible for the area ski resorts.

South of the Highway 50�1 to 3 feet of snow is expected.

Over the coastal range�heavy snow is expected along highway 36 and the Mendocino Pass along Highway 162 with 3 to 6 feet possible at the higher elevations. These snowfall amounts can lead to travel delays and road closures. If planning travel over the mountains�be sure to monitor the latest forecasts. Be prepared for hazardous winter travel.

 

[donbrown]

NOAA 19 DEC 630 AM PST

Adjusted altitude and decrease snow levels a very little

A Major snow storm is forecast to hit interior northern California late Thursday through Sunday.

Three to more than 5 feet of snow is forecast over the mountains through the three-plus day period at 5000 feet

Snow levels will be much lower in the Shasta County mountains�down to around 600 feet Thursday night before rising to above 3000 feet during the weekend. This means heavy snowfall along Interstate 5 is likely with possible accumulations of 1 to 3 feet.

The mountain valleys of Plumas County will also experience snow�with 1 to 2 feet possible in the Chester and Quincy areas.

Along the Interstate 80 and Highway 50 corridor�2 to 4 feet of snow is forecast�with higher amounts possible for the area ski resorts.

South of the Highway 50�1 to 3 feet of snow is expected. Over the coastal range�heavy snow is expected along highway 36 and the Mendocino Pass along Highway 162 with 3 to 5 feet possible at the higher elevations.

These snowfall amounts can lead to travel delays and road closures. If planning travel over the mountains�be sure to monitor the latest forecasts. Be prepared for hazardous winter travel.

Breezy to strong southerly winds are expected Thursday into Saturday with aviation flight level sustained winds of 40 to 50 knots at 3000 feet and 50 to 70 knots at 10,000 feet mean sea level.
--------------------------------------------------------------------------------

For MAmmoth 19 DEC NOAA 4 AM

The next winter storm will reach the area late Thursday, with the heaviest precipitation Friday night and Saturday. 20-23 dec

The storm will have the potential to produce up to two feet of snow over the highest elevations of the Sierra Nevada, and over a foot of snow down to the 5000 foot level.. Also associated with this system will be scattered rain showers and periods of light to moderate rain over the lower elevations and foothills.

Rainfall amounts should range from a tenth to a quarter of an inch in the San Joaquin valley to over a half inch in the foothills.

Yet another storm could reach the central California interior by Sunday evening 23 DEC.

25 DEC no storm

26 DEC NEW STORM very confident but forecaster focusing on 20 - and 23 DEC storms

 

[zilla]

Pretty soon a guy can travel or hit his more local spots,more untracked for everyone coming up!

 

[donbrown]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
519 AM PST THU DEC 20 2012

.SHORT TERM DISCUSSION (TODAY THROUGH SUNDAY NIGHT)...
IT IS GOING TO BE A BUSY WEEKEND WEATHER-WISE WITH FORECAST
CHALLENGES OF POTENTIAL SNOW IN REDDING AND THE OVERALL MOUNTAIN SNOWFALL AMOUNTS WITH WINDS.

CHILLY START AGAIN THIS MORNING IN THE SOUTHERN SACRAMENTO VALLEY
AND SOUTHWARD UNDER THE CLEAR SKIES. LOWER MID CLOUDS OVERNIGHT
KEPT REDDING AND RED BLUFF FROM COOLING TOO MUCH. IN FACT...THE
RATHER STRONG SOUTHERLY WINDS AT 2000 TO 3000 FT HAVE MIXED
DOWNWARD WITH 6 TO 12 MPH IN THE SAC VALLEY AND ACTUALLY RAISED
TEMPS A DEG OR TWO AT REDDING AND RED BLUFF. WITH A DEWPOINT
DEPRESSION OF 8 AT KRDD...ROOM EXISTS FOR EVAPORATIVE COOLING IF
WE COULD GET ANY PRECIP. LIGHT PRECIP LOOKS TO BE PRESENT OVER
WESTERN SHASTA COUNTY. WE DID HAVE A SPOTTER REPORT OF FLURRIES
EARLY THIS MORNING AT 2500 FT NEAR SIMS. THE FRONTAL SYSTEM HAS
MOVED VERY SLOWLY AND WE DO NOT EXPECT ANY PRECIP AT REDDING UNTIL
MID TO LATE MORNING WHEN TEMPS WILL BEGIN TO CLIMB. SO WE MOVED
BACK THE CHANCE OF SNOW FOR THE REDDING AREA UNTIL AT TOWARD
EVENING. THE GFS REDDING BUFKIT SOUNDING SHOWS SNOW BEGINNING NOW AND LASTING ALL DAY. SINCE THE COLD POOL IS NOT THAT COLD WITH
KRDD AT 38F...THE GFS SCENARIO IS UNLIKELY. THE EC BUFKIT HAS RAIN
TODAY AND CHANGES TO SNOW FRIDAY MORNING. IF THE TEMP CAN COOL
TONIGHT AS THE COLD FRONT MOVES THROUGH WITH SOME HELP FROM SOME
EVAPORATIVE COOLING...THE EC IS MORE REALISTIC. IT ALL DEPENDS ON
THE SNOW LEVELS. RIGHT NOW SNOW LEVELS ARE FORECAST BETWEEN 600
TO 1000 FT TONIGHT AND FRIDAY MORNING. DUE TO THIS
UNCERTAINTY...WE DELAYED THE START OF THE WATCH FOR THE NORTHERN
SACRAMENTO VALLEY ABOVE 500 FT UNTIL LATE THIS AFTERNOON AND
EVENING. BEST CHANCE FOR THE REDDING AREA WOULD BE LATER TONIGHT
AND FRIDAY MORNING.
COLD FRONT MOVES OVER INTERIOR NORCAL TONIGHT AND FRIDAY.
WITH STRONG SOUTHERLY FLOW INTO THE SHASTA COUNTY...HEAVY SNOW IS
EXPECTED AND TRAVEL OVER INTERSTATE 5 MAY BE SEVERELY IMPACTED.
PRECIP LOOKS TO REACH THE MOUNTAINS OF EASTERN SHASTA AND WESTERN
PLUMAS COUNTIES THIS AFTERNOON AND OVER THE NORTHERN SIERRA
NEVADA TONIGHT. LOW SNOW LEVELS EXPECTED IN THE EASTERN
BUTTE/TEHAMA AND WESTERN PLUMAS FOOTHILLS TONIGHT WITH SIGNIFICANT
SNOW POSSIBLE. BREEZY CONDITIONS EXPECTED IN THE CENTRAL VALLEY
TODAY AND FRIDAY WITH THE FRONT BUT AT THIS TIME IT LOOKS LIKE
WINDS SPEEDS WILL GENERALLY REMAIN BELOW ADVISORY CRITERIA.

RAIN AND SNOW OVER INTERIOR NORCAL FRIDAY WILL TURN SHOWERY FRIDAY
AFTERNOON INTO NIGHT. SNOW LEVELS WILL CONTINUE LOW OVER THE
NORTHERN MOUNTAINS BUT EXPECTED TO RISE ABOVE THE FOOTHILLS
FRIDAY INTO FRIDAY NIGHT. MORE WIDESPREAD PRECIP AND INCREASED
WIND AGAIN LATE FRIDAY AND SATURDAY AS THE NEXT FRONT MOVES
ONSHORE. A THIRD SYSTEM MOVES IN ON ITS HEELS SUNDAY AND SUNDAY
NIGHT. JCLAPP

.EXTENDED DISCUSSION (MONDAY THROUGH THURSDAY)
LAST IN THE CURRENT SERIES OF COLD PACIFIC FRONTAL SYSTEMS
FORECAST TO SHIFT EAST OF THE FORECAST AREA BY MONDAY MORNING.
THERE STILL EXISTS A THREAT OF SHOWERS MONDAY IN UNSTABLE AIR
BEHIND THE FRONT BUT THIS THREAT WILL END QUICKLY AS AN UPPER
RIDGE AMPLIFIES OVER THE EASTERN PACIFIC AND WEST COAST. MONDAY
NIGHT LOOKS DRY UNDER THE UPPER RIDGE AXIS AND WITH COLD AIR IN
PLACE...MANY VALLEY LOCATIONS LIKELY TO DROP BACK BELOW FREEZING.
GFS FASTEST TO BREAK DOWN THE RIDGE AND FAIRLY CLOSE TO GEM MODEL
IN BRINGING NEXT THREAT OF PRECIP TO THE NORTH STATE AS EARLY AS
TUESDAY AFTERNOON. ECMWF HOLDS THE RIDGE STRONG OVER THE WEST
COAST KEEPING TUESDAY DRY. HAVE KEPT TO THE GFS WHICH SEEMS MORE
IN LINE WITH MORE PROGRESSIVE PATTERN CURRENTLY IN PLACE.
WEDNESDAYS SYSTEM LOOKS LIKE A MODERATELY WET ONE WITH MODERATELY
HIGH SNOW LEVELS. EXTENDED MODELS REALLY DIVERGE BY DAY EIGHT
(THURSDAY) WITH VARIETY OF SOLUTIONS RANGING FROM DRY TO WET. FOR
NOW...KEEPING CLOSEST TO THE GFS WHICH COMES IN CLOSEST TO SEASON
CLIMO.

 

[donbrown]

NWS Hanford CA 6AM 20DEC

A Winter Storm Warning has been issued from 4 PM Friday until 4 AM Monday from Yosemite to Kings Canyon



STRONG DOWNSLOPE WINDS OCCURRING THIS MORNING THROUGH THE
GRAPEVINE ALONG INTERSTATE 5. HAVE ISSUED A WIND ADVISORY FOR THE
GRAPEVINE UNTIL NOON. WINDS WILL CONTINUE TO GUST TO AROUND 50 MPH
AT TIMES.

&&

.SYNOPSIS...
A STRONG WINTER STORM WILL IMPACT CENTRAL CALIFORNIA BEGINNING
FRIDAY AFTERNOON AND CONTINUING THROUGH THE WEEKEND. HEAVY SNOW IN
THE SOUTHERN SIERRA WILL CAUSE TRAVEL DIFFICULTIES. PERIODS OF
VALLEY RAIN ARE ALSO EXPECTED. THE FORECAST FOR CHRISTMAS DAY IS DRY
AND COOL ACROSS THE REGION.


very detailed huh?

 

[donbrown]

LAS VEGAS


LAS VEGAS NV
303 AM PST WED DEC 19 2012

.SYNOPSIS...DRY AND CHILLY WEATHER WILL CONTINUE THROUGH
FRIDAY...THEN ANOTHER STORM WILL BRING PRECIPITATION CHANCES TO THE
SIERRA BEGINNING SATURDAY AND SPREADING ACROSS MUCH OF THE AREA
SUNDAY AND MONDAY. TEMPERATURES WILL GRADUALLY WARM TO NEAR NORMAL
BY THE WEEKEND.
&&

.SHORT TERM...THE UPPER RIDGE WHICH WAS OVER THE AREA BRIEFLY
OVERNIGHT WILL SHIFT EAST TODAY. THE AREA WILL THEN BE UNDER A DRY
SOUTHWESTERLY FLOW THROUGH FRIDAY. SURFACE BASED TEMPERATURES
INVERSIONS WILL LIKELY BE PRETTY STRONG AND KEEP TEMPERATURES RATHER
CHILLY IN MOST AREAS TODAY WITH ONLY SLIGHT WARMING FRIDAY. A LARGE
LOW PRESSURE SYSTEM WILL DEVELOP OFF THE COAST AND BY FRIDAY NIGHT
MOISTURE WILL INCREASE AHEAD OF THE TROUGH ENOUGH TO BRING A CHANCE
OF SNOW SHOWERS TO THE SIERRA. THE TROUGH WILL SWING INTO CALIFORNIA
ON SATURDAY BRINGING A DECENT SHOT OF SNOW TO THE SIERRA WITH A
CHANCE OF RAIN AND SNOW SHOWERS SPREADING ACROSS NORTHERN AND
WESTERN INYO COUNTY AND ESMERALDA COUNTY WITH INCREASING CLOUDS ELSEWHERE. THE TROUGH WILL ALSO BRING AN INCREASE IN SOUTHERLY
SURFACE WINDS WITH BREEZY TO WINDY CONDITIONS IN THE WESTERN HALF OF
THE FORECAST AREA. THE INCREASE IN WINDS WILL WEAKEN OR BREAK THE
SURFACE BASED TEMPERATURE INVERSIONS...ALLOWING TEMPERATURES TO WARM
TO NEAR NORMAL DESPITE THE CLOUD COVER. THE TROUGH WILL WEAKEN AND
EXIT THE AREA SATURDAY NIGHT BUT LIGHT RAIN AND SNOW SHOWERS MAY
LINGER ACROSS INYO AND ESMERALDA COUNTIES.

.LONG TERM...SUNDAY THROUGH WEDNESDAY...THE ECMWF IS SHARPER THAN
THE GFS OR GEM WITH A LEADING PACIFIC TROUGH SLIDING INTO THE
SOUTHWEST ON SUNDAY LINGERING SHOWER ACTIVITY OVER THE SIERRA
THROUGH THE MORNING HOURS. THE MAIN EVENT IS FORECAST FOR CHRISTMAS EVE IF THE 00Z MODEL SOLUTIONS ARE RIGHT RESULTING IN A FAIRLY
WIDESPREAD QPF EVENT CHRISTMAS EVE DAY. UNCERTAINTY PROVIDED BY A
LARGER ENSEMBLE SPREAD WITH REGARDS TO THE STORM TRACK HOWEVER COULD
LEAD TO FURTHER NEED FOR ADJUSTMENTS AND REFINEMENTS TO THE FORECAST
OVER THE NEXT SEVERAL DAYS. ALL MODELS AGREE IN A DRY CHRISTMAS DAY
WITH STRONG NORTH WINDS BRINGING IN COLDER AIR. THE RESULT COULD BE
SIMILAR TO YESTERDAY WITH TEMPERATURES STRUGGLING TO REACH 50
DEGREES IN THE LAS VEGAS VALLEY UNDER A BLUSTERY NORTH WIND.

 

[donbrown]

ELKO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ELKO NV
310 AM PST THU DEC 20 2012

.SYNOPSIS...HIGH PRESSURE WILL BEGIN TO MOVE EAST TODAY ALLOWING
TEMPERATURES TO CLIMB A FEW DEGREES. ANOTHER STORM SYSTEM WILL
MOVE THROUGH THE GREAT BASIN BEFORE CHRISTMAS TO BRING MORE SNOW.
CHRISTMAS DAY WILL BE MAINLY DRY AND COOL WITH TEMPERATURES RISING
TO AROUND 30 DEGREES IN MANY AREAS.

&&

.SHORT TERM...TODAY THROUGH SATURDAY. IR SATELLITE IMAGERY SHOWS
HIGH CLOUDINESS OVER NORTHERN NEVADA DEFINING THE RIDGE CREST. THE
RIDGE AXIS IS RUNNING N-S THROUGH EASTERN NEVADA THIS MORNING. THE
MODELS ARE IN EXCELLENT AGREEMENT FOR THE SHORT TERM PERIOD.

TODAY THROUGH TONIGHT. HIGH PRESSURE IS PROGRESSIVE AND WILL
RAPIDLY MOVE EAST OF THE STATE TODAY ALLOWING A SOUTHWEST FLOW
ALOFT TO BRING RELATIVELY WARMER AIR INTO THE GREAT BASIN. WINDS
ALOFT WILL APPROACH 50 KTS HOWEVER MIXING WILL BE VERY LIMITED.
PRECIPITATION WILL BE LIMITED TO FAR WESTERN HUMBOLDT COUNTY
TONIGHT WITH LITTLE SNOW ACCUMULATION EXPECTED. HIGH TEMPERATURES
WILL GENERALLY BE IN THE 30S WITH SOME 40 DEGREE TEMPERATURES
ACROSS HUMBOLDT COUNTY. HIGH TEMPERATURES WILL BE HELD TO THE 20S
OVER WHITE PINE COUNTY WHERE SUBSTANTIAL SNOWPACK EXISTS. LOW
TEMPERATURES WILL GENERALLY BE IN THE TEENS WITH ANOTHER ROUND OF
BELOW-ZERO TEMPERATURES EXPECTED SOUTH OF HIGHWAY 50 AND IN THE
HIGHER VALLEYS OF NORTHERN ELKO COUNTY.

FRIDAY THROUGH SATURDAY. A PACIFIC LOW PRESSURE SYSTEM WILL DROP
SOUTH OF THE COAST OF THE NW CONUS THEN BEGIN TO OPEN UP AS A
POTENT SHORTWAVE LOW BY SATURDAY ALONG THE PACIFIC NW COASTLINE. THIS
PATTERN WILL ALLOW PRECIPITATION TO BEGIN TO ENCROACH UPON THE LKN
CWFA HOWEVER EASTERLY PROGRESSION WILL BE SLOW. SNOW ACCUMULATION
WILL GENERALLY BE LESS THAN AN INCH DURING THIS PERIOD AND TRAVEL
IMPACTS WILL BE MINIMAL THROUGH SATURDAY AFTERNOON. HIGH
TEMPERATURES WILL BE IN THE 30S TO AROUND 40. LOW TEMPERATURES
WILL GENERALLY BE IN THE TEENS WITH SINGLE DIGIT TEMPERATURES
EXPECTED SOUTH OF HIGHWAY 50 AND IN THE HIGHER VALLEYS OF NORTHERN
ELKO COUNTY.

.LONG TERM...SATURDAY NIGHT THROUGH NEXT WEDNESDAY. MODELS IN
GENERAL AGREEMENT SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH A BROAD
TROUGH OVER THE WESTERN U.S. ALONG WITH NEAR-ZONAL FLOW ALOFT OVER
NORTHERN AND CENTRAL NEVADA. MODELS ARE NOT YET IN AGREEMENT WITH
RESPECT TO TIMING AND AMOUNTS OF PRECIPITATION THROUGH THE WEEKEND.
AT THIS TIME EXPECTING SCATTERED SHOWERS SATURDAY NIGHT THROUGH
SUNDAY NIGHT WITH INCREASED AREAL COVERAGE OF SHOWERS ON SUNDAY
NIGHT OR MONDAY DURING THE FRONTAL PASSAGE. MONDAY NIGHT INTO
TUESDAY...

CHRISTMAS DAY...EXPECT GENERALLY DRY CONDITIONS WITH
COLDER TEMPERATURES AS THE CWA IS UNDER NORTHWESTERLY FLOW ALOFT.


MODEL SOLUTIONS SHOWING MORE SIGNIFICANT DIFFERENCES WEDNESDAY 26 dec AND
BEYOND JUST AHEAD OF ANOTHER TROUGH THAT IS EXPECTED TO BRING A
FEW MORE SHOWERS TO THE CWA.

 

[donbrown]

www.mammothweather.com 20 DEC says

2-5 feet friday thru Sunday ... even in town to 5000 feet.

Most of moisture to be late Sunday.

Winter Storm Warning Hoisted for Mono County for Late Friday Afternoon….Cold Upper Mother Low setting up for Series of Waves of Moisture into Southern Mono…..2 to 5 Feet expected by Monday AM……Longer Range Pattern Suggests Storm Track Shifting South With Time Hitting Southern Sierra Head on after New Years……..


Thursday December 20, 2012


Posted at 7:38 am by Howard
.



The Dweebs have had plenty on their plates well ahead of their upcoming tradition holiday feast! We keep looking for the classic NW Atlantic Block to develop forcing a strong -NAO to the ridge up the west coast +PNA fashion, but at this time it is no where in sight! One reason is that the hemispheric pattern is in a -AO and at least a 5 to 6 wave progressive pattern. So the high latitude blocks that would normally form in key areas for some reason are not setting up. Additionally….The cold arctic reservoir is over extreme Eastern Asia and again for some reason, mother natures likes it there.

This may continue the process of energizing the series of short wave coming off the Asian Continent across the pacific and eventually coming into our own backyard…later in the year as suggested by last night GFS run. The pattern at the moment is full latitude blocked at about 168W, with the block building well into the Arctic. Possibly because of the very strong Asian Jet…the block gets undercut with time pinching off a cut off Upper High over the Bering Sea. The block may reform again or……..??

Currently Pattern:

A deep upper low off the coast of the Pacific Northwest will shift a 5-6 series of systems into northern and central Ca through Monday AM.Of note there is a lot of Subtropical moisture coming north west of Hawaii that is expected to feed into the systems as they swing through the long wave and then into the central and west coast. As the strong westerlies busts through the block later this weekend the entire amped upper trof comes through Sunday night! The heaviest snowfall with be as the main upper low comes through Later Sunday/NGT. Orographics are singing a tune of 3 to 5+ feet for the Mammoth area top to bottom by Monday AM.

Christmas Eve will include improving conditions with short wave ridging Christmas Day. Christmas Day up on the hill will sport crystal clear skies, a blinding sun, light winds and deep powder on the upper runs……

No "major" storms evident until 31 DEC to 2 JAN