Sunday…the 17th,

The GFSX just finished running and not surprisingly it too has picked up on the retrogression of the eastern pacific ridge next weekend and the eventuality of the -EPO blocking pattern over Alaska. The resulting westerly flow undercuts the block and sets up a milder mid pacific storm track, compared to the more northerly track we have experienced the past several weeks. Modified Arctic air has been the theme with the dominate polar jet  the past weeks….  That looks likely to change with more Maritime pacific air masses moving more zonally across the pacific. This too is potentially a wet pattern for the Sierra. Although we do not know, as it is too early, where the East Asian jet will set up over California, it potentially will bring a period of wet storms to California with a series of AR filaments brushing the golden state.

In the mean time for the upcoming week, it will be cold in the high country with inside slider systems bringing periods of snow showers with light amounts of snowfall through Thursday or Friday. Highs will remain below freezing low 20s, with lows single digits at 8000 feet.

 

The Dweeber……….:-)

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Sunday 6:00am. 5 day storm total on Mammoth Mt.  5 to 8  feet…. More to fall today… 3 to 6 inches

 

11:30pm

Just a quick look at the new 00z feb 17 euro this evening, shows a large positive upper height anomaly developing over Alaska in the EPO region days 8  9  10.  A strong belt of lower to mid latitude westerlies is working its way east toward the central west coast. This would initiate a series of ARs with a mid latitude storm tract during the week 2 period. In that the EC is better at distance…The Dweebs will keep a wary eye on this trend. This has the support of the MJO.

BTW..it looks unlikely that the current typhoon over the west central pacific will have any affect on the westerlies…the tropical storm does get absorbed by the westerlies, however little if any amplification occurs…

 

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From Saturday AM;

Platinum Powder now falling over Mammoth Mt with about another 12 to 18 inches expected by Sunday evening…most of which will fall today as the last of the storms including Wednesday night and Thursdays AR, moves south and east. This month of February has been exceptional!

The hemispheric pattern has been exceptional as well with parts of the pattern acting more like La Niña with the negative PNA over the west while the equatorial pacific mimics El Niño…..quite the combination.

For the most part..the MJO has wagged the winter dog since December. I think that we are dealing with a Nino basin that is in a weak El Niño state while at the same time the atmospheric coupling has been greatly suppressed by some large-scale upper convergence…

Looking at the dynamic models…the MJO is progressing slowly east..so there is going to be a pattern change week 2. The  MJO or ERW has already spawned a typhoon in the west-central pacific which depending upon its phasing with the westerlies, may throw a monkey wrench into the longer-range models for the last week of this month. I will also add, as In the previous discussion; where the MJO is located, it favors AR’s. If this MJO does not get off the dime soon, it is just a matter of time before the west coast gets hit with another AR. It is not being shown in the GFS week 2, but is gaining ensemble members in the European week 2 period with an awesome extension of the EAJ on this mornings 12Z run. On the contrary, the climate models as well as the GFS are not as yet picking it up. So confidence is low at this time.

 

In the meantime…it will  be cold this week with periods of snow showers and below normal temps…great for carving turns  on California’s premier ski mountain….the following weekend storm is in question again.

 

 

High temperatures will remain below freezing for the next 5 to 7 days.

 

Dr Howard and the Dweebs…………..:-)