Mammoth Mountain Reported up to a foot of fresh Powder this afternoon with more bands of showers expected this evening….Expect a fair dry weekend with high clouds and moderating temperatures……

Its been a while since a cold trough moved through the sierra from the Eastern Pacific. This time, there was no split and this time a pair of Vort maxes following the main trof axis passage, brought unstable air and snow showers today.  This will continue for a time tonight as the flow becomes more WNW and some of the shower north of the bay area, possibly swings into our area tonight.  This is all great news for the Mammoth Mt Ski Area with storm totals now 8 to 12 inches! That’s a big deal this winter!  Temperatures will moderate upward into early next week with lots of high clouds and lighter winds at the surface. Highs will climb into the low 50s by Sunday or Monday. Lows will move back into the 20s from the current single digits and teens.

Reflecting on the Late Fall and winter so far, the global pattern across the north hemisphere has been dominated by meridional Flow (North-South) since December.  This is likely to continue through at least part of February as the QBO remains in its negative phase and of moderate strength. The MJO is becoming very strong and will strengthen further as it moves into the Western Pacific and toward the Dateline about week 3.   SEE: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpe.shtml 

Then   http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/emom.shtml

This may repeat the pattern we had last December with strong ridging developing over the far Eastern Pacific/west coast in the coming weeks with dryer than normal weather continuing. The East Coast will get hammered again with Arctic Air. I’ll be following the progress of the pattern change which will remain in its warm phase in the east until phase 7 of the Rimm, provides the open door for the Arctic Highway for the East and extensive ridging for the West again.

Just as a note; I have noticed that the effects of the MJO, with relation to modulating the East Asian Jet, frequently behaves differently during winters when the QBO is in its “positive phase” contrary to what we have today.  There is often more Zonal Flow across the western hemisphere which tends to foster more successful undercutting’s of the west coast ridge and more successful central west coast extensions of EAJ and resulting Atmospheric Rivers. It is not to say that they are impossible, but more improbable.  With the current set up of the QBO, currently in its Easterly Phase or negative phase, meridional flow dominates, which combined with the current weak to moderate La Nina, may be the stronger force working against the MJO’s modulating effect upon the westerlies in phase 7-8-1.  If you click on the link above, you will notice that the MJO strengthens and then makes a run for Phase 8.  Watch the models toward that time period, and see how they want to amplify, then retrograde the west coast ridge. I bet that there will be models runs with the westerlies showing undercutting into the west coast. Keep your heart on this as there are strong forces working against any undercutting reaching the central west coast through mid February. The Pacific NW may benefit with “AR’s” during weeks 2 and possibly 3.

Opine: Looking at how strong the trades are getting again, and if they keep up current strength at this pace, we may be in for a protracted La Nina period, that goes well into the Summer.  The good thing to remember, is the QBO will eventually flip back to positive later this year and that is likely to bring winter back to the central west coast with more generous amounts of precipitation next year.

Just to Add:

For those who are interested in the QBO, here is a link that gives an easier explanation as compared to the abstracts written by actual scientist’s. I think that you will all agree that after going through all the analog’s in the various links associated with the link below, the screaming message is that there is a very strong bias for drier and warmer winters in California with the QBO in its negative phase during weak La Nina’s such as the one were are currently in.

http://www.daculaweather.com/4_qbo_index.php

 

The Dweeber……….:-)

Couple of systems headed our way this new week…Best in the group still expected Wednesday Night and Thursday….

Tuesday Morning 8:30 AM

After a mild day today with light winds and highs in the mid 40s, the next weather system will bring increasing winds late tonight with wind advisories in effect for the Mono County area beginning at 10:00AM Wednesday through Wednesday night, 10:00PM. Snowfall will begin here in Southern Mono County Wednesday mid to late evening and will increase during the early morning hours Thursday.  This storm system is different from last weeks fiasco as its energy will lift through the sierra and not split and head south down the coast. Thus orographic’s will come to play and amounts being only moderate as there “is not” an atmospheric river associated with it. The Dweebs are expecting approximately 6 to 10 inches above 8000 feet including the crest and 4 to 6 inches between 7000 and 8000 feet. It is possible that the crest may see a bit more as again,  orographics come into play combined with colder temps. This will provide for higher than usual snow to water ratios.

This mornings forecast calls for about .75 hundreds QPF.

The weekend looks partly cloudy with milder weather and slowly rising temperatures Saturday through Monday.

The next weather system will come through by about month’s end.

 

The Dweeber………………..:-)

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New 00Z Monday the 22nd GFS is running at the moment and consistent with this mornings run in bringing a storm Wednesday night into Thursday with moderate amounts over the upper elevations and light amounts in town. Light category is 1 to 6 inches and moderate is between 6 to 18 inches. Contrary to the last system and as of this time, the energy is expected to come through the sierra instead of diving south down the coast.  The southward dive of the storms dynamics is what caused the lack of precipitation on the east side last week. Will update the details of this weather system for Wednesday night and Thursday,  tomorrow and again Tuesday to make sure that there are not any changes in the development as was the case with the last storm.

In the meantime we have a small system that will bring some snow showers late tonight into the late morning hours Monday.  Anyware from a dusting in town to an inch or two over the sierra crest is possible by noon Monday.

 

Dr Howard and the Dweebs…………………:-)

Chilly Storm left 4 to 5 inches on Mammoth Mt….the splitting systems main energy is headed through LA tonight….Next system will trend further north…..Mammoth Mt “may” get simular amounts

Friday Evening:

As always, a disappointment when we need snowfall and you end up with 4 to 5 inches on the hill when a foot is expected. As indicated below, the storms main vort max is headed into Southern Ca tonight. The system split well off shore. The next upstream systems main energy is well to the north. However, it is not splitting! So we may get a pleasant surprise to the 1 to 2 inches expected by Monday. 3 to 4? No promises….

Models still looking forward to a more significant system mid week…..Stay tuned….The models have all promised this before….

Won’t get excited until Monday if it is still holding together….

 

Dr Howard and the Dweebs……………:-)