Strong Ridge Trough Pattern to Break This Week as Eastern Pacific High Retrogrades just west of 140W Early Week 2…..Long Wave Trof to set up over the inter- mountain west for cold storms and fluffy snow Early Week 2….There may be a few small storms later this week….

The pattern change at this distance in time is a bit tricky as the Arctic air that is setting up over the Northern Midwest and Great Lakes region is forced to flush east and off shore by the next weekend… Initial track of pacific storms will be from the NW, through the west coast ridge that is breaking down this week for mainly light to possibly moderate precipitation with the best chance next weekend. Also we do not know how far west or how close to the coast the initial vort lobe is going to be that the GFS has in its proggs mid-week. No matter, this does not look like much. Just more of a nuisance system. The short wave is headed through high pressure and so light precip is mainly the possibily.

By the weekend or just beyond, the eastern pacific ridge retrogrades and amplifies just west of 140W, which in late January and early February is a cold pattern for CA. Long wave teleconnections suggests, coastal or inland sliders with varying amounts of over water trajectory. However, more time is needed to work out the details. A lot will depend upon how amplifyed the pattern gets.

MJO Support;

The GFS is consistent in its strong MJO through phase 7. The ECMWF is not as strong but at least is trending into 7 now….Good Support for a wet California week 2.

Familiar Ridge-Trough Pattern across the Country brings an end to the Active Pattern of the past several weeks….With Sierra Snowpack now above normal….Winter Sports are in Full Swing!!


Ok, Sabbatical off but time off to move early next week….We do have a pattern change next week. Both the GFS and CFS, but not yet the ECMWF, are showing the MJO going into Phase 7 which can be wet in early February. SEE:

I use the Phase Space as support for the Global Models in the week two period. The MJO Composites do show more support in January for this pattern but early February is fine…. Phase 7 of the RMM2 supports retrogression for the Long Wave features over the eastern pacific (EP) to initially allow for the weakening of the west coast ridge, then retrogression of the feature afterword’s. The most likley pattern to develop is a cold Trof to set up either over the far west with some over water trajectory for light to moderate Cold Storms with light fluffy snow, or… further west for a cold-wetter scenario. There is also the possibility of subtropical moisture getting into the mix as one of the global models is trending to a REX Block, long enough to spin up a subtropical low with some phasing possibilities. We will not know how all this will come together for at least another 3 to 7 days when it gets into an earlier time frame. I will mention that “if”, and it is a big if, the MJO decides to remain strong and travels further east, toward and over the Nino Basin, that would be phases 8 then 1, which could end up a very wet pattern with an AR. So far the European model is not picking up on all this, either in its week two period or its MJO forecast. So, confidence is lower than what would be the case if the opposite were true. I would say that the odds are greater than 50% at this time.

In the meantime enjoy a weekend of January Thaw!! 🙂

Thursday Evening the 24th;

West Coast Ridge/Eastern Trof will dominate the pattern the next week with mostly sunny days and fair nights. High temperatures will range from the Mid 50s this weekend to the mid 40s next week. Nighttime temps in the 20s and teens. Expect light winds except over the Sierra Crest on Friday. The upper ridge does show some tendency to weaken by the end of the month, leading to lots of possibilities as we go through the first week of February. The GFS has the MJO forecasted to go into phase space 7 week 2, which can be wet this time of the year…. However, many of the models keep it in phase 6 which is dry. In the meantime, the Dweebs will take a sabbatical for the next 7 days unless there are clear signs of what kind of change is in store for us all…..The Dweeber…..:-)

A major pattern change is underway that will bring milder temperatures to the high country and an end to storminess for at least a week to ten days. The players and support show the MJO moving into Phase 6 next week in which composites show as dry for January in California and cold and wet in the east. This Ridge/Trough pattern is anchored by a deepening Hudson Bay Low and a highly amplified ridge over the far west. The Wave Length will be very stable. A January Thaw is likley to develop later this week sending high temps into the low 50s by the weekend. Lows at night at the village location will be in the teens by Mid week, then 20s over the weekend. At the Moment the Central Sierra is some 120% to 130% above normal in snowpack. Mammoth Mt is filled in with an 7 to 11 foot base, bottom to top. Skiing and riding are what you would expect on California’s favorite Mountain for this time of the year!

Next Series of storms will develop sometime during the Month of February…..Climate Model CFS V2 suggests possibly during the end of the first week in February…

In the meantime, high temperatures will go from the low 30s today Tuesday, to the low 50s by this weekend with cooler temperatures arriving by the following Monday.

As soon as the Dweebs have a better idea on a significant change, this blog will be updated…..In the meantime enjoy!!

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

Stormy Week on Mammoth Mt had resulted in 4 to 7 feet of fresh powder…..One Last smaller storm to bring up to another 8 to 14 inches Sunday Night…Week Long Break likely with next possible storm series beginning about February 1st….El Nino atmosphere coupling no where to be found….All the better!!

A Winter Weather Advisory is hoisted for Sunday night….  No change in the expected snowfall amounts for either the Mountain or the Town of Mammoth Lakes.

4 to 8 inches in town and some 8 to 14 inches on Mammoth Mt by Monday morning….

After a fair dry Saturday….Snowfall will begin mid to late afternoon Sunday and continue through Sunday night….Snow Showers are expected through Mid Morning Morning….

Snow showers ended this morning leaving partly cloudy skies…..N|S Upper Jet axis over NV this AM translating east. Saturday should be a day for the Blue Birds although some high clouds possible… Sunday the last in the series of storms rolls in mid to late afternoon. Should be a moderate snow producer for the upper elevations. Mam MT- 8 to 14 inches – 4 to 8 in town.

MLK holiday Monday looks partly cloudy with morning snow showers… breezy but nice….The week looks dry with high temperatures in the 30s and 40s. lows in the teens….

Next pattern change to wet may occur about the 1st of February. What are the Dweebs seeing?

Yesterday’s Climate forecast model, (CFS) and associated MJO phase space were a lot different than both the GFS and ECMWF. It showed the location of the enhanced convective state of the MJO moving to the Phase Space 7/8 of the MJO index. This track usually is professed with an increase in amplitude in the eastern pacific ridge that ends up with a teleconnection, (-EPO). IE Upper blocking over Alaska. The transition in phase space from 7 to 8 to 1 is usually accompanied by retrogression of the block over AK (-EPO) to near the Bering Sea….(-WPO) Mother Nature has a habit of extending the EAJ well into the eastern pacific during these times as the upper jet gets modulated/enhanced eastward. It is noted that both GFS and ECMWF did not show any of that. In fact to the contrary, the MJO dives into the circle of death in phase space 6 of the RMM-2 (western pacific). So there really is no agreement to believe from yesterday or even this morning by the MJO index to support the CFS at all. However, for the second day in a row the CFS has it again. Also, looking at the Week 2 progs of the GFS, both the 06z Friday and 12z Friday showed the -WPO teleconnection and extension of the EAJ to the eastern pacific. So… it is picking up on something! I would say that if the MJO index RIMM begins to mimic the CFS tomorrow AM, after several more GFS runs today and tonight, I will begin to have more bias toward the CFS tomorrow. At some point, if the CFS stays consistent, the GFS and eventually the ECMWF will come around. Climatically, anytime in February is ripe for this (-WPO) undercutting pattern…. Timing? During first week of February.