Archive for year 2018

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…


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.


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………………………….:-)


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……………………:-)

First Fall Storm of the wet season making its way to California early next week…..Precipitation is likley but how much….Never trust a storm this time of the year!…..


Fridays Headline is above still applicable for this afternoon Saturday. Models still struggling with pattern along with TS Rosa moisture.  New ECMWF is back again from three days ago bringing in a 3rd system that is colder for Midweek. More moisture from Rose is in play as well with the Tuesday and Wednesday time frame. The 3rd system will move in Thursday and it is colder with more wind. European is beefing up QPF as well.  So the Yo Yo is in full swing this afternoon. Can’t wait until there are multiple runs for the same scenario. We continue to struggle with a low confidence forecast, even 3 to 4 day away.

The up shot from all this is the same as the Dweebs have been touting. If you going into the backcountry in the upper elevations, especially above 10,000 feet, bring winter gear next week just in case it snows. This afternoons NCEP WPC QPF is back up to an 1.00 of moisture over the Crest next week.

Why is all this change going on in the models. It is Fall and early Fall into October along with Mid march into April are notorious for model flip Flopping. The content is cooling off, and the Pacific Ocean is coming into play.


Just enjoy some of nature’s best!


The Dweeber……….;-)



9:40AM Friday

GFS has just finished running and the tracking of the second system, takes it to the Bay Area, then South East along the coast line to San Diego. This is much like last nights 00Z and 06Z runs. In this scenario, most of the cold air remains to the west of the sierra crest along with the precip. If by chance the storm swings inland a bit more to the north, then more precip would be expected. At the moment, about .25 to .35 is expected over the Mammoth Sierra Tuesday into Wednesday. A few inches of snowfall is certainly possible. The Southern Sierra should fare better with up to 8 to 10 inches over the higher elevations where there is more vertical motion, more moisture and being closer to the upper low itself, colder aloft.  The snow level over the southern part of the Southern Sierra will be possibly 7000 to 8000 feet.

The CRFC has the freezing level above 11,000 ft Tuesday over the Mammoth Crest Tuesday. Typically snow levels with a system like this are about 1500 feet below the freezing level.  So about a 9500 foot snow level is certainly possible during the main part of the storm Tuesday.  This storm is likely to bring a good dusting as temperatures will cool further by Wednesday AM with the snow level dropping briefly to about Canyon Lodge


I update again Later Saturday.


Dr Howard and the Dweebs……………………:-)



As headlined, we will be greeted by our first storm of the season Tuesday of next week.  Precipitation is likely Tuesday, however, more time is needed to know what part of California will benefit best.  Those hiking in the back country need to keep a weary eye on the forecast as there are enough differences in the models to warrant….

Next up date in an hour…..

Enjoy the next few very nice days ahead as major pattern change takes shape…..Undercutting storm track may pick up some badly needed moisture from TS Rosa for good precip producer next week…….

9/27/2018 AM Update

Forecast models have come in considerably drier this morning with precipitation for the Tuesday and Wednesday time frame. TS Rosa will not, as of this time, be a player in contributing any additional moisture to the system for the Sierra next week. That closed low approaches the coast Monday, then drops SE along the coast Tuesday and Wednesday. Rosa’s moisture looks destined to affect Northern Baja to AZ, which is more climatically favored for this time of the year. As mentioned below, it is still September and models do not do as great a job in the medium range as they do during the winter. Nevertheless, this mornings guidance still suggest that at least a quarter of an inch of precip is possible and that would translate to a few inches in the high country.  This may flip-flop several times in the coming days so back country travelers do not let your guard down…..  All in all, it looks like at the least, a good dusting for the high country!


Stay tuned!


Dr Howard and the Dweebs………………….:-)




Although High pressure aloft will strengthen the next few days bringing warmer temperatures. The upper high is expected to build north over AK over the weekend as a vigorous belt of westerlies for Late September and Early October undercut and drive into California. With antecedent warmth well established over the Eastern California, there is no doubt that at least moderate to possibly strong winds will develop on Saturday. Pray the Aspens hold on to their leaves this weekend! 🙂


The pattern is complicated as Hurricane Rosa, now gathering strength west of Manzanillo MX, is expected to track NW,  west of Baja, CA.  Although this storm by the end of the week will be weakening as it moves over colder waters, its moisture is suggested to get somewhat entrained into the southern part of the westerlies. It is not completely known how much of it will get into California at this time, but the models are starting to turn wetter. There is also a cold part of the storm expected to come in Monday night or Tuesday. This would no doubt bring significant snowfall for the backcountry with any additional moisture from Rose.

The principle point here is that anyone planning a trip to the back country, leaving this weekend and traveling next week will need to have their winter gear ready! Snow, Winds Chills, hypothermia are all possible in a snow storm in the high elevations of the backcountry. Some model simulations bring up to a foot in the back country and if more moisture gets involved from Rosa, those amounts would rise. If the opposite occurs, then less snowfall would be expected.  The Town of Mammoth will have much lighter amounts. Especially on the roads that are very warm from the Summer. Will update later this week on snow amounts in town if appropriate.


Going this strong with a forecast of the possibility of snowfall in the backcountry in late September is dicey.  Forecast models are not as trustworthy as they would be in December through Mid March timeframe, However, I have to say that as of this time, the Global Models all show snowfall in our back country beginning Monday night and for several days thereafter… stay tuned to future developments…  For those of you that are headed for the backcountry, you need to keep especially informed…


Dr Howard and the Dweebs……………….:-)