First Hard Freeze to the High Country this morning with lows in the teens….Sunny Cool Days ahead with warmer weather this weekend…..Signs of the westerlies sagging south the Last Week of the Month…..

It was a cold one this morning with lows temps in the upper teens. Dew points were near zero and so no frost was in the picture either.  Today’s 500MB weather maps showed cold air advection behind a front and trof that came through the high country last night.  The config of the pattern showed a ridge off shore and low Pressure to the SSE.  For this week, a NNE off shore flow continues through Thursday as an upper low spins up over AZ.  Then the ridge off shore builds inland this weekend into the pacific NW, kicking the upper low over AZ out.  This pattern is a dry one for the high country and it will remain rather chilly, especially at night. As the upper ridge build into the pacific northwest this weekend, high temps should climb some 5 to 7 degrees by the end of the week. I expect low’s in the upper 20s and 30s at night this weekend at the Village at Mammoth, not teens…

The longer range is like this:

The GFS has the westerlies sagging south the end of the month while the ECMWF stays dry.  The Forecast for the ECMWF has winter storms returning to the high country by Mid November on the 00z October 11th run. I expect that product to be updated either today or tomorrow and I will report…The EC in the longer range is usually a better tool than the GFS.

 

Dr Howard and the Dweebs………………….:-)

Intermountain Trough of Low Pressure will remain in place the next couple of days locking in below normal temperatures along with the possibility of Snow Showers along the Eastern Slopes of the Sierra…Mainly Between Tonight and Thursday Evening…..Only a very light dusting is expected…Expect a warming trend this weekend into next week with dry weather…..

As highlighted above, the aforementioned intermountain Trof will remain in place through Thursday, but will split on Friday as the northern portion progresses east into the northern Mid West and the southern part spins up off the coast of Southern CA.  At the moment, it is expected that Mammoth Will remain north of the favorable NE quad of that low with just some easterly winds into the weekend.  The upper high over Alaska will progress west into the pacific NW later next week and will be part of a REX BLOCK, where by the an upper low trapped underneath the upper high will initiate an easterly flow. At this time, it is thought that any upper divergence from that upper low will remain to our south. However, If we do get anything from it, it would be around the 19th of October and it would not be much precip.

Looking down the road and considering the MJO Phase space, the MJO does circle back into 8/1. So another -EPO is possible before the end of the month. Any speculation beyond that is wishful thinking….   As a note, the  -EPO is associated with the undercutting of the westerlies.

Expect high temps now in the low 50s to climb ot the low 60s by Sunday or Monday and upper trend in Temperatures are expected later next week.

Many Nights now are below freezing and for the foreseeable future… 20s and 30s

ENSO:

At the 850mb level, anomalous westerlies have shifted eastward, with the largest anomalies centered near 110 W. This westerly wind burst continues to increase the availability of warm waters along the equator, increasing the likelihood of a transition to El Nino for the boreal winter.

 

The MEI will update tomorrow…

 

Dr Howard and the Dweebs………………:-)

 

Forecast models have now converged on a wetter solution for the sierra with anywhere from between 1/2 inch to up to an inch of precip through this Thursday……The snow level for most of the event will be above 10,000 feet

8:30AM Thursday; 10/4 good buddy

Upper closed low opened into a short wave last night and was located over Northern AZ this morning.  Two more short waves to go,  through the week’s end. One today and one Saturday. Each has the potential bring us light precipitation amounts. Today’s outlook shows about one-quarter inch and a couple of inches of snow above 9500 feet. Saturday only a 10th of an inch is expected, so maybe an inch of snow, above 8500 feet. Chilly weekend!  Lows may drop below freezing Saturday night and Sunday night.  Time to replace that Summer Comforter to Fall Comforter for bedding now? Maybe…

Climate models show warmer temps last 10 days of October for Indian Summer…..:-)

PS Check out Updated El Nino comments below…

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10/3/2108 Update

Light rain to moderate fell upon the Town of Mammoth yesterday with isolated late afternoon and evening thunderstorms….(.54) inches of water fell from our skies over a 24 hours period.. The Freezing level was between 11,000-12,000 yesterday and so most precip was rain over the sierra. The moisture was drawn northward from Tropical storm Rosa which is now long gone. The next shoe to drop is the closed low off the Southern CA coast. It is making its way toward the coast now and should make landfall later this afternoon. This time there will be plenty of dynamics and vertical motion from the upper lows NE quad.  Much of the sierra will be effected from a deformation zone north of the low. (Surface convergence). Odds are there will be more thunderstorms from this pattern. Also, with more convection comes the possibility of lower snowfalls. This is different from the snow levels which will be above 10,000 feet for the most part.  The snow level will come down a bit over night as another wave comes through from the Pacific NW Thursday morning. Friday will be dry.

Beginning this weekend, the closed high over Alaska (-EPO) with be replaced by a full latitude ridge at about 140 west. This ridge will tap cold Canadian air and pull it down over the Great Basin and California. This can be one of our colder weather types for the Eastern Sierra. It is usually associated with the MJO, “The Madden Julian Oscillation” moving Through Phase Space 1……The Northern Hemisphere and Africa. The upper jet is usually focused on the back side of the digging cold trof down the West Coast then shifting east through California and Nevada then north over the Rockies. This pattern will bring light showers and cooler temperatures.  It is only when the upper jet is stronger and diggs further west offshore that our weather becomes more remarkable. In this case, we can get snowfall to lower elevations. Amounts vary depending upon the proximity of the upper jets, left Front Quad to our location.

 

Next weeks weather will be dominated by this large-scale Great Basin Trough developing this weekend with a particularly interesting short wave dropping south from the Alaskan Fjords. This may bring us some measurable snowfall in town with a solid freeze in town Mid Week. It is not certain my any means, but it is showing up more often than not in both GFS and ECMWF model runs.  Stay Turned……

 

High temperatures this week will be mostly in the 50s Today and Thursday with low 60s this weekend. Nights will be in the 30s.  I am expecting some twenties by next week.

 

EL Nino:

There is a 50-55% chance of El Nino onset during Northern Hemispheric Fall (SON) 2018, increasing to 65-70% during winter 2018-19. • Note; The strong westerly wind burst east of New Guinea the last few weeks is likely to improve these odds for the next release of El Ninos update for the CPC, 11th of October update.

10/04/2018

The Dweebs had a peak at the latest CPC, CFSv2 Nino SST Forecast through the winter of 2019

This is in reference to The El Nino that’s currently building.

The most remarkable point to make is that in looking at yesterdays forecast numbers, it only shows a few tenths of a degree Celsius difference in the Nino 3.4-3 region as compared to the Nino 1+2 region. The prind point here is that there is not as much support of a Modoki type El Nino in the latest guidance as compared to last month for the upcoming January.  In addition, the trend is away from a Modoki type event. The El Nino forecasted is more suggested of a quasi full basin type. However, what it also shows is that it is weak to moderate El Nino.  More later after the 11th. I will report on the state of the El Nino Forecasted, later in October.

 

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

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It appears that we will be getting our first wet fall system of the season in the high country, beginning after midnight Monday night into Thursday. Currently, the circulation of TS Rosa is moving on shore today and some of that moisture will move north and will add to moisture that is flowing in from the pacific. There is a closed low that is currently located about 1000 miles west of Malibu, Ca. today. This is the system that will provide the dynamics on Wednesday for the potential of heavier showers in Mono County. The low itself is expected to move through Southern CA Wednesday night. However, a deformation zone ( area of surface convergence) is expected to set up over Mono County Wednesday afternoon and allow slower moving storms to form with the possibility of heavy rain in some areas Wednesday afternoon and evening.  By Thursday, the low will be gone, but not before another cold front moves through Thursday morning. This system will wring out what ever moisture is left in the air mass from Wednesday night into Thursday. If we get a dusting at Canyon Lodge, it would be later Wednesday night into Thursday morning.  As far as significant snowfall goes, It looks like for the most part it will be well above 10,000 feet. However, there could be snowfall accumulation’s in the 6 to 12 inch range from about 10,500 feet and above. Wednesday afternoon and night appears to be the best period of the heaviest snowfall at the highest elevations as the pattern looks a bit more convective.   High temps will be in the upper 60s today Monday and 50s on Tuesday and Wednesday and Thursday. Lows at night at resort levels will be in the low 40s tonight, then cooling to the low 30s or cooler by the weekend.

 

Longer Range:  

American Models, GFS has Great Basin Long Wave Trough setting up over the weekend into next week. If this pattern verifies,  it can develop light snow showers along the eastern slopes of the sierra along with strong gusty winds at times over the higher elevations and well below normal temps next week.

Stay tuned as we may be missing a lot of our warm early fall weather for more late October like weather….After all. its has been one of the warmest summers on record and mother nature’s often times balances things out a bit with colder weather into the following season….

 

Note; The cold weather coming next week is being forced by the MJO.  Its moving into Phase space 1 from 8 this weekend.  Looking at the MJO Temperature composites, the signal for October is Cold in the west and warm in the East.

A Strong ridge building at 140 West will result in a Deep Great Basin Trof, bringing very cold air in west for October. Snow showers for the high country will be a possibility with light accumulations a good possibility. Light accumulations are 1 to 6 inches of snow.  Hard Freeze possibilities will increase the next week. Keep your eye on temperatures and your landscaping pipes. May want to blow them out this weekend if temperatures are expected to remain well below freezing for several hours.

Pattern like this often repeat themselves in December. Look out if it does…..!!!

 

Dr Howard and the Dweebs……………………:-)