Archive for year 2021

SnowMegeddon! Week two suggesting storm after storm through years end!

12/13/2021

Todays guidance and the ensembles, continue the trend, that this stormy period for California is just beginning and that it is likely to continue beyond Christmas. The main point here is that the eastern pacific ridge “retrogrades” during week 2 ) next week and that pulls the long wave west for more storms with good moisture taps. Snow Megeddon is an eastern colloquial term that is being used for not one storm but the accumulation of many between today and years end.  There is a particularly large one, that will possibly hit around Christmas, the timing will be better kn own by this weeks end,  A lot will depend upon how strong the AR is.  There seems to be several weak ARs in store for the high country through years end.

The Dweeber……………………….:-)

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So the models are in this afternoon and all are in agreement that the pattern will remain active through the 28th. It will not snow everyday as there looks to be a break developing some time next Friday into Sunday. The QPF suggests a solid 10 inches of water through next Friday. Somewhere between 8 and 10 feet of snowfall over the upper elevations for Mammoth MT is still reasonable for the combined two storms. There looks to be a break next weekend., however, the following week will bring the opportunity for more moderate to heavy snow producing storms as well.  Next week the main the upper jet seems to favor the southern half of the state more than Northern California. Good for both the Southern and Central Sierra, Good for Mammoth! .  Amounts will be updated later this week but preliminary Est are some 4 to 6 inches of water, (without a major AR). I say that as although all model runs do not show a major AR in many runs, there are enough ensemble members that still have it considered, so only time will resolve this issue. If we do have a Moderate or Strong AR, then all bets off on snowfall next week as it will be, “Snow Megeddon!”  Most likely time frame around Christmas.

This Monday Tuesday storm has a very low end moderate AR (barely Level 2) So far, it appears that this Monday-Tuesday storm will bring the heaviest snowfall totals in the shortest period of time.

BTW, the IVT forecasts from the GFS show the potential for a weak AR on the 23rd and the European, a moderate AR on the 26th.   It seems that the idea of a significant AR keeps is still in the cards, it is still possible and until we get closer to the week 2 period, we can only watch with interest.

In the meantime, I expect Mammoth Mt to have the best Christmas and New Years Week skiing, in several years!!

 

Happy Holidays!!

 

Dr Howard and the Dweebs……………….:-)

 

Temperatures going below normal for protracted period of time as WX pattern shifts into active mode…..MJO shifts into phase 7 then phase 8 with possible Major AR resulting for Ca around Christmas….question is Where?

So the long awaited Active Pattern is shaping up nicely.  Upper high in the right position feeding short waves via AK south east into long wave trof.  The combo of the Thursday storm and the Sunday night through Tuesday night may dump some 6 feet of snow on the upper mountain. Amounts forecasted will adjust over the next few days so stay tuned as there is an decent, categorically weak AR with it and so amounts can change up or down.

The main point here is that the long wave appears to be locked in for a few weeks. Shure glad I was not one of those dry foot long range forecasters touting doom and gloom! Last month I shared a scientific paper about La Niña, and the negative phase of the QBO. One of the points in the research paper was that there was a stronger correlation for the MJO to continue east, past that LA Nina area of upper convergence into the central pacific, Phases 7/8. More frequent strato warms too.  Last winter the MJO ran out of gas over the western pacific. What the current forecast suggests is that it will remain strong into phase 8.  The results deepen the PV over NE Asia and pump the central pacific ridge to kingdom come. Eventually cutting off the high with the potential of a southern stream jet into CA later this month. This suggests; 1st a lot of snowfall for the Sierra up to about The 22nd.  Then if the MJO actually makes it strong into phase 8, the “the potential of a very significant AR for a part of CA.  This is a teleconnection, not a forecast so just sit back and enjoy the big snow producing storms for the next 6 to 10 days. By the time we get to week 2 the models will let us know if a large AR is in the offering……. California needs the water so let’s hope we get lots. Just hope it does not turn to rain…..

 

Dr Howard and the Dweebs…………:-)

Transition underway with unsettled weather this Monday Night and the next system Thursday bringing the potential of a foot of snow……Larger storms lurking the following week..

Monday night:

GFS seems to have resolved it’s closing offer or cutting off scenario, as the massive storm for early next week is loaded with cold Alaskan Arctic air.  It’s currently depicted slowly moving into California Sunday with its baroclinic zone somewhat stalled over Central CA, Sunday night through Monday night or Tuesday.   Although lots can change in 5 to 7 days, it looks like a monster.

stay tuned……..

 

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All global models in agreement that week 2 will be stormy. Big question is,  when will it get going that week.  Could be as early as Monday or as late as Thursday.  The problem with the week 2 period is, the GFS model cuts off the first big system, off the coast early that week due to strong down stream ridge over the Midwest.. We may get some light snowfall or nothing until the upstream kicker gives it the boot. Then some cold heave snowfall. The ECMWF is more progressive (quicker) so it will be fun to watch how all this gets resolved. Main point is, And as stated earlier, snowpack should be good by Christmas, if long range model trends continue. It’s too soon to guess on how much snow will fall week 2. But amounts that are tallied in feet are certainly possible. The pattern wants to continue through the solstice and beyond….this La Niña looks pretty cold from the way it’s shaping up for December.

 

In the meantime, there will be a couple of small storms this week.   One Monday night/Tuesday AM that may drop 1 to 3 inches of snow and another colder storm Thursday that will drop about a foot on Mammoth Mtn. The following weekend looks dry. Then the fun begins for the Weatherman. Several Dumps on the Way next week…..Looks like its going to be a white Christmas with deep snow!

 

 

The Dweeber…….🥸