Last in the Series of storms hit the sierra this weekend…then a nice break next week……………………..

Friday AM:

Changes in the weather pattern across the far eastern pacific and downstream are becoming less conducive for storminess over the next week.  The East Asian Upper Jet stream is weakening as the main area of tropical forcing along the equator weakens and redevelops over the Indian ocean.

The immediate effects in the next two weather systems headed for the Sierra are:

 

  1. The Splitting of the Friday/Night storm due to a shorter wave length created by the upper low now lifting into Texas.
  2. This will have the effect of weakening it to where most of the precipitation for our area will fall on Mammoth MT or the Sierra Crest…….With a lot of shadowing as you go east.
  3. Snowfall estimates for Mammoth Mt are about 7 to 14 inches by Saturday AM;  (3 to 7 in town)

 

The next and last in the series of storms will move into the sierra after midnight Saturday night with the remains of it moving out Tuesday AM.  This system does not dig as much or have the depth that the models showed earlier in the week. Again, this is because of the weakening and retraction of the earlier extension of the *EAJ. With both of these storms, there will be a lot of wind. The snowfall forecasts for the Sunday through Monday Night look like more in the 1 to 2+ foot range now. So the 3 to 5 feet that was touted two days ago is off the table and more likely 2 to 3+ feet over the upper elevations between this Friday and Tuesday AM.  The Town of Mammoth should get between 3 to 7 inches from the Friday/Night Storm and 6 to 12+ from the Sunday Through Tuesday AM system.

Wind:  The 2nd weather system coming in later Saturday has a nasty West NW upper jet. So it will be a windy one…right on into Monday….

Long Range:

With the East Asian Jet continuing to retract, a full latitude fair weather ridge is probably going to develop over the far eastern pacific later next week.  However…..The pattern becomes progressive again by the end of next week or beginning of the next as both the ECMWF and the GFS has another series of storms headed for California.

Last nights ECMWF brings a storm into the west coast on Sunday while the new 12Z GFS this morning shows it more like Monday. However, using the Hovmoller method, there isn’t any Surface Cyclogenesis out at 140E (off the coast of Japan), until Friday night the 18th…..which via the Hovmoller method, would propagate the short wave energy through our state Tuesday night the 22nd.   So The Dweebs are not sure about what the models are seeing for a Sunday or Monday storm.  It may be delayed a day or two.  Stay Tuned on this one……More later on the long range next week…..

 

*EAJ = East Asian Jet

 

Dr Howard and the Dweebs…………………..:-)

 

 

Mammoth Mt picked up another 8 inches over the past 24 hours…a nice break today with unsettled weather returning late tonight and into early Wednesday…..Another Major Storm Expected by the end of this week….Storm Door to Close During the 2nd half of next week….

Wednesday AM:

All forecast models are back peddling a bit on the QPF between Today and next Tuesday indicating about a 4 inch Bull’s-eye over Mammoth.  That means that we could see between 3 AND 4 FEET OF SNOW BY NEXT Tuesday.
The AR forecasted for early next week looks much weaker in the models today.

That appears to be the end of this storm cycle as the upper jet lifts back to the north. However,. Winter is not done yet and The Dweebs expect that the last week of the month of March to be quite active with more snowfall……

 

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Skies dawned clear this morning after an unsettled day Monday. A nice short wave ridge builds in today with milder temps. The ridge is dirty and so high clouds will return by Noon. Gusty winds will increase this afternoon into tonight.  Highs today in town near 40. Low of 25.

Upper pattern will remain progressive through next Tuesday with a series of weather systems. The highlights are:

  1. Light over running precipitation late tonight through Wednesday AM. Light snowfall is expected over Mammoth Mt.  (1 to 3 inches)
  2. Winds will begin to ramp back up later this afternoon over the upper elevations into tonight.
  3. It will remain breezy to windy over the upper elevations beginning later today through Sunday.
  4. The next storm will move in Thursday Night and will end early Saturday. That system had been showing signs of splitting according to the GFS over CA. The ECMWF model has been more consolidated all along and now the GFS is showing more consolidation with the “Upper Trof” as well with this mornings run. This trend is more favorable for strong UVM over the Sierra Friday AM. Additionally, the new 12Z guidance is showing the front left quad of the upper jet favoring the Central Sierra at 12Z Friday AM.
  5. Although the Jury is still out on snowfall amounts by Early Saturday AM, it seems that a foot of snow or better over Mammoth Mt is reasonable, at this point in time.
  6. After the storm moves out early AM Saturday, it may actually be a decent day with wind over the upper elevations but little or no snowfall. The EC shows the potential for some nice wave clouds in the AM for Early AM photo shoots.
  7. By later Saturday afternoon the clouds increase with the wind, as the Last in the series of deep upper lows approaches the west coast. The system has an impressive upper jet that will move into Northern CA 1st, then slide south as the upper trof reloads and deepens. Several weather fronts will move through with this system Saturday night into Tuesday AM. The ECMWF has a nice atmospheric river associated with the strongest upper jet Sunday night through Monday AM.  The Dweebs are expecting 4 to 5 feet over the upper elevations during the period “Saturday night through Tuesday AM”
  8. There will be a long break in the storminess by Mid-Week next week as the upper pattern stagnates as a result of the EAJ receding. The GFS develops a full latitude ridge over the Eastern Pacific later next week with just a hint of a break through of the westerlies by weeks end.  The ECMWF is not as bullish with 500mb higher heights, as well as the upper jet remaining well north week 2.  Looking at the MJO and its composites, the MJO is pretty weak the next few weeks cruising through Phases 3 and 4 then strengthening in phase 5. However, the MJO is destructively interfering with the El Nino base state next week. That will assist in supporting the pattern change for the week two period….To go dry along much of the west coast. With the return of convection north of AU….the SOI has gone positive. This may also aid in a quicker weakening of ENSO base state in the coming 4 weeks as well..
  9. The Dweebs at this point are in agreement with the ECMWF and believe that the end of this particular Storm Cycle associated with moisture leaden storms from the pacific will be ending by the middle of next week.

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

 

Between 4 and 5 feet reported on Mammoth Mt with a couple of feet in town….The next system rolls in later tonight with more sunshine expected by late Monday AM into the afternoon…..Snow showers expected Monday PM…..

Monday AM:

Upper jet diving south toward Baja this morning as upper low slows and slides SE. The Dweebs have seen this scenario before.  Essentially, this storm will not come through the sierra. Rather…it digs south into BAJA, Mexico. Coastal sections of California will likely get the lions share of precipitation while east of the Sierra into NV only light amounts. I suspect that the Winter Storm warning will be dropped at some point today. I personally am surprised that it is still up this morning.  The Dweebs still expect some wrap around snowfall this morning and possibly this afternoon, but again, amounts will be light….. 1 to 6 inches over all…

The Upper Jet makes a return to the sierra by Friday……Some over running precip still possible mid-week.

 

Update late today:

 

The Dweeber…………………………:-)

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The Next Short wave  has moved on shore and will be climbing the Sierra tonight.  QPF is about 1.25 to 1.4″ in the San Joaquin drainage by Monday PM.  Considering early orographic’s,  snow to water ratios which will be higher in this storm,  and the fact that a secondary impulse will dive south down the coast in the Early AM, 16 to 20 inches on Mammoth MT seems in the ball park and between 8 to 15 inches in town. There may be a bit more shadowing with this system.

Mid Week:

I have to say that this is not your typical ridge between weather systems. The models are bringing in a lot of warm air advection (over running). QPF forecasts are always problematic with (WAA). No doubt that there is going to be light snowfall now, later Tuesday into Wednesday. It will probably be around the 3 to 6 inch range on Mammoth Mountain and 1 to 3 in town.

Sorry for the bad news…It appeared earlier that we would get a clean break between storms mid-week, before the Thursday night/Friday storm arrived.  Warm Air advection is often times associated with a lot of high elevation breeze. So be ready for that if you are on the mountain mid-week. Winds really pick up Wednesday night into Thursday.

 

The next significant storms looks to have a good SW fetch and although the main short wave splits a bit as in comes into CA, it should be a good precip producer for the Sierra.

 

Thereafter, a large synoptic scale, adjustment/long wave trof will provide for a moist, consistent flow of moisture into the Sierra next weekend, for at least light to possibly moderate snowfall.  The Dweebs do not see another AR event until we approach the middle of the month of March. However, the pattern remains active.

The two-week outlook keeps the hits “right on coming”!

 

Dr Howard and the Dweebs……………………..:-)