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!!

Friday;

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

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.

The last but not least of the 3 sierra storms getting ready to hit the high county by Tonight…..Winter Storm Warnings hoisted with a special emphasis on Blizzard Conditions later tonight! A break in the Weather is expected Friday and Saturday with another smaller system expected Sunday night….Next week looks dry with milder temps….

9:00Am Thursday AM Update:

Mammoth Mt Reports 24 hour snowfall amounts up to 4 feet of fresh snow. Winter Storm Warning is in effect until 4:00AM Friday. Upper elevations for the period 4:00AM this morning through 4:00AM Friday could pick up another 1 to 2 feet for a total 5 day snowfall of between 7 and 8 feet over the Mammoth Crest.

The Eastern Sierra Avalanche Center in Mammoth Lakes has issued a BACKCOUNTRY AVALANCHE WARNING:

* TIMING…In effect from Wed 6 PM PST to Fri 7 AM PST.
* AFFECTED AREA…The eastern slopes of the Sierra Nevada mountain range between Virginia Lakes on the north, to Bishop Creek on the south.
* AVALANCHE DANGER…The avalanche danger for the warning area will rise to HIGH tonight and will remain at HIGH thru tomorrow and tomorrow night.
* REASON/IMPACTS…Heavy snow combined with wind will result in widespread avalanching.
* PRECAUTIONARY / PREPAREDNESS ACTIONS…Very dangerous avalanche conditions. Travel in avalanche terrain is not recommended. Avalanches may run long distances and can run into mature forests, valley floors, or flat terrain.
*As a note, Mammoth Mt is an avalanche controlled area with snow safety devises that is much safer than the outlying back country area.

Cold Unstable air will bring periods of heavy snow today. Snowfall amounts at the Village could add another foot+ to last nights accumulations. Friday will have improving conditions with the chance of snow showers and light snowfall accumulations. 1-2 inches. Saturday looks partly cloudy and dry. Another but weaker storm may bring another 1 to 5 inches of snow to the 7000 to 8000 foot level and between 4 and 7 inches to Mammoth Mt by Monday AM. The remainder of the new week looks dry and milder….Excellent week ahead!

Next possible stormy period beginning about the 1st of February.

Note: El Nino has not yet coupled with the overlying atmosphere, over the tropics. The current pattern is being modulated possibly by the MJO. The Dweebs are expecting a highly amplified pattern developing later this new week which “may” end up with an under cutting of the westerlies by the first week of February. The Dweebs main focus will be on this possibility and will watch and report on its development next week for the longer range. Dr Howard and the Dweebs…………….:-)

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As of 1:00PM; winds were pretty steady over the crest of Mammoth Mt with 65MPH, gusts 75-80MPH; In town, winds were SSW 15 to 30MPH. SFO Radar showing leading band of Precipitation already on shore over the Bay Area with pockets of heavy rain now occurring. Snowfall is into the Northern Sierra south to Alpine County. Looks like there is a small band of showers over the Sawtooth Range west of Bridgeport, CA.

The Updated HRRR model begins snowfall over the Mammoth Crest about 3:00PM with snowfall increasing in town around 4:00PM. It will be light…..

Winds will steadily increase this evening as a 970MB surface low west of Northern CA heads towards the Pacific NW.
PWAT within the storm is approaching 1.2-1.3 inches over our region by Mid Evening Wednesday. 850mb winds from the south-southwest will increase to 50-55 kts. This strong flow will combine with high moisture content to produce onshore IVT values of 750-850 kg/m/s, categorizing this event as a strong atmospheric river. Copious amounts of precip will occur tonight into the early mornings hours here in the high country. Expect a good four to five feet of snow over night over Mammoth Mt with 2.5 to 3.5 in the Town by Thursday evening. Most of this will fall tonight into Thursday AM.Local Blizzard conditions will hit tonight and continue into thorough 4:00AM Thursday. Snowfall will wind down Thursday evening…..The weekend looks partly cloudy with highs in the 30s and lows in the teens. Another smaller weather system will bring light snowfall Sunday night….Then a long break of a week or more…. PS…this is no El Nino…..So far the convective effects of El Nino has not awakened…..

Dr Howard and the Dweebs…………….:-)