Archive for May, 2020

Record Heat for Eastern California developing the next few days with summer like late afternoon thunder expected….Cooler breezy weather to return by weeks end….More breezy weather next week with seasonal temps….

Tuesday May 26th Update

This Morning’s GFS shows the Cut-Off Low shifting further east before turning northward Thursday.  Should this new track of the Cut Off verify,  this puts the favored NE quad of the Upper Cut Off far enough south over CA  to bring upper divergence over the our portion of the sierra Friday afternoon. The timing also coincides with max afternoon heating. (00z Saturday)  This raises the question whether Mammoth will have scattered thunderstorms Friday afternoon and evening due to the change in track of the cut off.  This is different than today’s convective forecast, which is more like a typical summer like thunderstorm pattern due to the warm up in process.  More later………



The heat will build in the high country the next 3 to 4 days as a strong upper ridge quickly builds over California. The upper ridge is actually getting super charged by a cut off low that will be quasi stationary the next 36 hours west of Baja before it begins to lift NE toward the Northern CA coast later Thursday. The action of the low provides an increase of heights at 500MB and also some moisture being drawn up from Mexico.  Strong surface heating along with areas of surface convergence will drive isolated thunderstorms over the Sierra the next few days.  Tomorrow Tuesday looks especially good for some high based storms near the Glass Mt ENE of Mammoth later in the afternoon.   This heat wave will be record setting with highs in Mammoth and the Owens Valley eclipsing the old records for the dates set back in 2003. This Wednesday through Friday period will be the warmest days for the Owens Valley and Tuesday and Wednesday in the Mammoth Area..  Bishop will experiences highs between 100 and 103 and Mammoth 80 to 83 degrees. It will pull back into 90sand 70s respectfully over the weekend. Isolated Thunderstorms are possible through Friday in the high country… Those storms will shift more to the north over the weekend as the upper cut of moves on shore just north of the Bay Area.

Cold Upper Low off the Northern CA Coast Monday AM will move south…then inland over the Bay Area Monday night…..Cold Pool will shift east later today bringing light snowfall to the Town of Mammoth with Moderate snow to Mammoth Mt today and tonight……Cold Unstable Air Tuesday will keep snow showers going Tuesday….A glance at Memorial Day weekend….Weather fair and breezy 1st part then warmer Sunday and Monday……

This mornings weather pattern is highlighted by a long wave trof just off the west coast the first part of this week. The current system is highlighted by a significant upper low and cold pool off the Northern CA coast with 500MB heights of 545 centered just west of the OR/CA border at 12Z Monday. The leading edge of a large cold 1000-500 thickness pool extended from, a 546 dm iso line from Tahoe to the Bay area then west to 135W. This thickness pool has 1000-500MB thicknesses slightly below 540DM off shore, which will move into our area later this afternoon and overnight. 1000-500mb thicknesses as low as 541 DM by 06Z. is projected over night tonight. Thus the rainfall currently occurring in town will change to snowfall this afternoon and continue into tonight.  Snowfall amounts of 1 to 3 inches are possible overnight . Upwards to a foot over the Mammoth Mt summit is expected.

Another note worth mentioning, this is cold core funnel season, (mid May into mid June).  Well see how the SPC looks tomorrow AM for that afternoon….


After a chilly Tuesday with highs in the low 40s,well below freezing temperatures will occur both Tuesday AM and Wednesday AM in town.  The upper low shifts east Tuesday night along with the long wave trof so that the next upstream system drops southeast into the Pacific NW and Northern Great Basin, then to the Northern Rockies. This is a dry pattern for Mammoth but the warm up expected Wednesday into the following Thursday will pause to allow the subject system to more well northeast of our area.  High temperatures will be in the upper 50s Friday and Saturday and it may be a bit breezy; then rise some 5 to 10 degrees Sunday into Monday, Memorial Day.  (Mid 60s)


Long Range: Next Week

Long Range outlooks are always dicey this time of the year with so much changes in the models. However, as a hobbyist;  It is fun to try with best guesses.

So here goes


Both ECMWF and GFS has a ridge in the mean along the west coast providing an off shore flow and above normal temps along the coast. However, recently, operational model simulations have a cut off low that gets the boot into California next weekend as well. Both model simulations show this cut off low that develops in the subtropics off South Central Baja, this weekend,  that remains off shore next week, then again, gets the boot into the CA coast. The GFS has the trajectory so that light precip is projected  for extreme Northern Ca and the EC Southern Ca which would be a convective pattern for Mammoth..  Stay tuned!!!

More next week…..


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

First Week Of May will be Warmer than Normal…..Extended Outlook (6 to 10 day) shows warm tranquil weather with out any significant wind or precipitation….

It is almost like mother nature flipped a switch that took us from the cold season to the warm…

There was some anomalous weather Sunday as the front right portion of the upper jet over Northern CA brought strong down sloping, compressional type heating to the Owens Valley. As a result, Bishop was some 30 degree warmer than Mammoth. Bishop had a high of 83 Sunday while Mammoth was 53. Monday morning began rather cool in Mammoth with a low of 28.

Today Monday, is an uneventful day as far as any dynamical and sensible effects upon the atmosphere.


The Upper Jet is lifting slowly to the north without any down-sloping or any Adiabatic (compressional type heating) expected for the Owens Valley. As a result, even though 500MB heights will be higher today, the warming will occur in the high country, whereas the Owens Valley may be a degree or two cooler today.   However, by Tuesday, a sensible jump in temps will occur for all of the Eastern Sierra. Expect mid to upper 80 in Bishop, and upper 60s in Mammoth Lakes, Tuesday.

By Midweek, A short wave will move to the north and bring an increase of breeze and pause our warm up for a day. In back of the wave, ridging will build in strongly and will eventually build up into Canada, North/South over the far west.  This cuts off flow from the pacific over the weekend, As a result, high temperature records will be in jeopardy again…  Highs in Bishop will reach mid to upper 90s at the Airport while Mammoth enjoys a comfortable 75 Saturday….. low 80s in Bridgeport.  Short wave action returns Monday for breezy and somewhat cooler weather….


Dr Howard and the Dweebs…………………………:-)