Archive for April, 2017

As the Fishing Opener has come to a close……Warm Sunny Days are here to stay…At least through the middle of this week….A change in the pattern highlighted by a developing “Cut-Off” low will bring the chance of showers and thunderstorms, with the chance of showers beginning as early as this Thursday through the weekend and beyond.

Its been a beautiful fishing opener, with light breezes over the lower elevations and bright sunny days.  Temps on Sunday topped out in the low 60s while at Crowley Lake, it hit 70 degrees on Sunday. The upper ridge off shore will actually build into California late Tuesday into Wednesday, then shifts east into Nevada Thursday. Because along the western periphery of the upper ridge, we have southerly flow, we get one more day of warming Thursday.  Highs will be close to 70 in the Town of Mammoth.  However, like during the summer, once the upper ridge shifts east, our air mass becomes more unstable with the beginnings of cooling aloft. Towering cumulus just like during the Summer in the afternoon will develop with the possibility of diurnal afternoon and evening showers.  Remember, the first week of May is like early to mid August with the high angle of the Sun.

Following the upper ridges passage, is an upper trough. This trof is progressive and will move to the west coast by this Friday morning. Strong gusty southerly winds will increase over the upper elevations as the rear right entry region of the upper jet approaches. This will destabilize the atmosphere even more continuing the chance of showers. It will be cooler Friday through the weekend with the chance of showers each day and evening. Note: The showers look mostly convective and thus diurnal in nature.

More on next weekends storm:

The upper ridge is forecasted to sharpen up as it slowly progresses east to Eastern Colorado this Saturday, then stalls out. This forces the upper stream trof over California to become Cut-Off from the westerlies. So this is our first cut off low of the Spring the weekend of the 6th.  Cut off lows are very unpredictable and at this time, it is not uncertain where the cut off will develop. For what it is worth, all the forecast models today Sunday afternoon, are trending more toward a stall out along the coast of California as the cut off tracks very slowly SSE. This low may be with us between the upcoming Saturday through the following Wednesday and possibly beyond. This will prolong the possibility of showers and thunderstorms each and every afternoon and evening until it exits.

More later this week…..

 

Dr Howard and the Dweebs………………………:-)

Blustery Northwest Jet will keep weather unsettled this week with cool windy showery weather…….Warm-up expected by the end of the weekend….Longer range shows a nice warm period beginning the first week of May….

For the Dweebs, this is my least favorite time of the year.  It is the transition season between Spring and Summer with the northwest jet prolonged through Northern and Central CA. The Jet is tilted NW/SE as a long wave upper high inside of 140 west is too far off shore to bring warm temperatures and too close to California for any major storms. The front right exit region favors the sierra with “Wave Clouds”, so you wave cloud photographers, will have the opportunity for some good shots this week in the early AM hours and late afternoon mostly areas east of Highway 395.  The NW jet with its front right exit region over the central sierra favors convergence aloft in this sector. Downward vertical motion results in strong winds at times aloft and mainly orographically induced snow showers. 

It will be quite breezy to windy over the upper elevations on Mammoth Mt most of this work week.

There will be nuisance snow showers this week, mainly Monday through Wednesday morning. However, the showers will not add up to much of anything.  I call it nuisance weather!  But it is necessary to get the season along before summer finally hits in June.  Expect highs in the 40s and low 50s with lows in the 20s and 30s.  Winds will Crank at times to 80MPH over the crest with gusty winds in town as well.

Will there be one last storm before summer hits?

Maybe more than one….

I just had a peak at the European Ensembles for week two. (next week) It shows; 1st,  The sharpening of the upper ridge off shore without the progression of it into California. This argues against any big lasting warmup. It shows a cold low dropping SW from Alberta Canada on the 1st and settling in over the Western Great Basin on the May 2nd.  There after, retrogression takes place with the next short wave dropping south down the west coast. Meanwhile, the upstream ridge retrogrades west and builds up into Alaska, (-EPO) style.

So here we go again!!  Remember, this is the Euro, not the GFS.

 

The Climate Models CFS climate forecast system suggest that the 3rd week of May will be colder than normal with the chance of snowfall.  No telling how much though.

 

 


Atmospheric River in process ending Tuesday afternoon by 5:00PM….Then on and off showery weather into Thursday followed by a very warm fair weekend…..

4/19/2017 Update:

 

Our Atmospheric River shifted south late yesterday, leaving 2.17 inches of water in the Rain/Snow melt tip bucket this morning. Mammoth Pass picked up another 4.00+ inches of water and Mammoth Mt reports a storm total of 18 to 26 inches of fresh snowfall.  A big story this morning is that Mammoth Mt crossed the 600 inch mark for snowfall for the season with 605 inches.   However, the bigger story is the amount of snow and water that has fallen out of the skies over the past 6 to 7 months. That is 98.57 inches of water. This is most likely a record.  Crossing the 100 inch threshold is going to be the biggest news when it happens!   Sure a 600 inch snowfall winter is note worthy, but a 100 inches of water from both snow and rain is nothing short of amazing!

I am expecting a few showers tonight followed by a beautiful sunny warm weekend!   It will be windy next week with a slight chance of showers…..

 

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

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The Great winter of 2017 continues to wind down. The upcoming week shows the likelihood of light to possibly moderate precipitation at times through Thursday. There is a weak to moderate AR in process. This is acting to keep the snow level closer to the freezing level which is more common during air masses that are very moist. The freezing level will be on the high side today Monday and through Tuesday night.  As a result, precipitation will fall mostly as rain or snow or in town as the freezing level remains well above 8500 to 9000 ft.

Monday night and Tuesday would be best chance of accumulating snowfall at 8000 to 8500 feet. But being that the roads are so warm, there will likely be just some slush to deal with over the higher elevations of town.  Snowfall amounts will be in the 1 to 3-inch range Monday night into Tuesday, mainly the Village west. It will be especially breezy to windy, through the middle of this week.

On Mammoth Mountain, the guidance suggests that between the period of Sunday the 16 and Thursday the 20th, the upper mountain may get 2 feet plus at elevations above 10,000 feet. It will be wet snow at the main lodge with amounts more in the 8 to 12 inch range This is not from one storm. Rather the combination of three between Sunday night and Thursday evening.

It is important to mention here that this week’s storminess will be followed by a beautiful Spring weekend with much above normal temperatures. However, the European model runs still favors more unsettled weather the following week. The American Model the GFS is dry for the same period.   Whether a storm for week 2 shows up or not, expect an update on that later this week. Comment: (Does it not usually storm on the fishing opener?)   As a note, the Dweebs feel there will be a few storms in May and possibly June as well. We have yet to see the Cut-Off lows over the Great Basin develop this season. They will show up eventually!

 

Weather Discussion:

The blocky pattern over Alaska currently in process suppressing the upper jet stream south over Central CA will be retrograding westward later this week.  This change in pattern usually signals a northward shift in the upper jet stream and an extended period of fair weather for California. There is even the possibly of our first real Spring thaw for the Eastern Sierra this upcoming weekend into early the following week with highs near 70!  In the meantime, it will be windy this week until that change in pattern mentioned above kicks in.  I expect high temps to cool to the upper 40s through mid-week then a warm up through the weekend.