2 Major Winter Storms headed for the Sierra Saturday Night/Monday-Tuesday…….Platinum Powder Alert for Tuesday and Wednesday…….

Sunday AM: 12:22

Snowfall rates now 1 to 2 inches an hour.  Back edge of front now moving east through San Joaquin Valley

Lower end of snowfall estimates now likely for the Towns of Mammoth and June.


Update Mid AM



10 to 15 inches in town and up to two feet over the crest.

*PLATINUM POWDER ALERT FOR Tuesday and Wednesday. Ratios:   (Snow to Water  20:1)

18 to 24 over the higher elevations Monday into Tuesday.


Friday AM:

Two Significant storms headed for the high country.  Each has a good chance to bring about 2 feet over the crest and a foot+ to the Towns of Mammoth and June.  What is interesting about the 1st storm is the coupling of both subtropical and polar jets off the Ca coast.  The best focus for the heaviest precip will be over the west-facing mountains of Northern CA where the upper jets focus the highest moisture transport near the front left exit region of the Polar jet for a longer period then the Central Sierra.  The upper jets do sag south with time, into the Central Sierra later Saturday and into Early Sunday AM.

In looking at the new CRFC QPF data, they give Yosemite only .90 of QPF.  The Dweebs believe this is way under done as that amount would only put about 10 inches to 12 inches over the crest W/orographic’s.  Considering the pattern…I like HPC’s QPF of between 1.50 and 1.75 for the Mono County Sierra and so amount up to 2 feet over the crest seem more reasonable considering the pattern.  Sunday looks snow showery with little if any additional accumulation.

Next System:

The Monday storm is the last in the series. Although it does not have the STJ coupled with it, the upper jet is cyclonically curved and punches in from the west, right over us.  It is cold as well with 500MB temps of -30C and 700MB Temps of -10C to -12C Both Tuesday and Wednesday

Although the QPF is similar….I expect more from that storm because of the higher Snow to Water Ratios….



Upper long wave reloading tomorrow, in back of a short wave upper ridge moving through California Friday for a dry day.

The Saturday afternoon and night system has changed considerably now. The screaming message here is that a significant development has shown up in the latest modeling that involves the coupling of both subtropical and polar jets off the California coast.  This leads to the possibility of a tropical connection and pseudo atmospheric river event for mainly Northern CA and will include Central Ca, but for a shorter period. This moisture transport and 700-850MB moisture flux will range 3 times above standardized anomalies into Northern CA.

The Central Sierra will get plenty of heavy snow fall with this system, however, not to the excessive degree as the Northern Sierra.  Will have a better handle on things in the morning as far as the QPF and the effects of this storm on the Mammoth area.

Dr Howard and the Dweebs………………………:-)

Although this first storm system looks weaker now….The hits will keep on coming as moderate to possibly heavy systems line up for their move into CA

Thursday 1:00PM

Fellow Dweeb Dan McConnel just texted me from the top of Mammoth Mt.  He Indicated that there was almost 18 of fresh snow on top from the last storm….  Great News….!


Just checked in with Joni Lynch at Marketing for Mammoth Mt.  She indicated that Mammoth Mt still plans on being open until Memorial Weekend. That Canyon and Little Eagle lodges will stay open until the 20th of April.

The Weather is now really cooperating. We have a series of storms that will be bringing new snowfall through Tuesday of next week.  The Dweebs expect the Saturday night storm to be capable of at least 1 to 2 feet now and that more will fall from the Monday/Tuesday Storm. In fact the national weather service has already hoisted Winter Storm Watches for the Sierra.  This system has a rich moisture tap from the Subtropics.   Will update the QPF Friday.

Although the outlook calls for a break the 2nd half of next week,  the long range shows the potential for another 60 to 70 inches of snow over the upper elevations through early May!


Thursday AM:

Mammoth Mtn reported a foot at the main lodge……There was 4 to 6 inches in town….possibly 15 inches over the Crest.

Brief update……Storm has exited the area. Unstable air aloft in the wake of the storm will still produce some snow shower activity today. Friday will be dry and a good travel day if you’re traveling up to the high country. The next storm will move in Late Morning Saturday and by Sunday we expect another 1 to 1.5 feet over the upper elevations.

It will be snow showery Sunday morning…..The next system is for Monday afternoon and night……..High temps in town in the 30s today and 40s on Friday…..More later……>>>

The Dweeber……………………….:-)


Wednesday Update: 9:25AM

At this time, some sunshine is peaking through….we are in-between bands of snow. Another band has left the Bay Area and is now into the SJV…So more snowfall is expected a little later this AM.

Amounts seem pretty consistent with yesterdays discussion. An Updated 3 to 8 inches in general for Mono County excluding the upper elevations 9K to 11K where amounts will be in the 12 to 16 inches range by Thursday AM.

The next storm for Saturday is on track to bring about a foot to a foot++ over the upper elevations Saturday afternoon/night.


The following storm for Monday afternoon, “and this is an update from this morning”, is much larger now, showing up on the 12Z GFS as a storm capable to 2 feet+…..

As is often the case, the 3rd in the series is the biggest as it often has the most upstream amplification. This system has an initial confluence of the subtropical jet and it could really have explosive development…..More later in this particular storm for Monday/Tuesday…..

There after….. the models still have more storminess in our future, well into May.

The Sub-Climate model “CFS” from NCEP shows 6 to 7 inches of water between today and the 10th of May. That would be another 60 to 70 inches of snow at 10:1.

Better late then never?……………………..Don’t you hate snow farming?

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




This mornings computer output did scale back a bit on snowfall estimates with amounts probably closer to a foot+, than earlier predictions of up to 1.5 feet over the highest elevations. Satellite loop this AM did show the front developing a forked tail in the southern section, indicating a break within the front and a less steady precipitation pattern expected late tonight into Wednesday. It will certainly be the 2nd section that will bring the burst of heavier snowfall later Wednesday AM and with the upper jet still favorable early in the PM that should keep things going longer post frontal. So the Dweebs will scale back the snowfall estimates for the Tuesday night/ Wednesday system a bit. The town should still get somewhere in the 4 to 7 inches range, bottom to top, by the end of the day Wednesday.

It may not be a two plow storm but a good one plow by the end of the day Wednesday.

Thursday will be showery with upslope westerly flow. There may be a few more inches possible as well with more over the crest.

If I were a blue bird, I would be singing my tune early Friday AM to the delight of the skiers and boarder’s. So plan on getting up early to Cut it, as the winds will be coming up in the afternoon, ahead of the next storm Saturday.

The next shot of snowfall will move in Saturday afternoon, (timing subject to change) and into the night. Again,  that will be preceded by some pretty strong gusty winds Friday night into Saturday.  Sunday looks showery…..then another storm expected to hit Monday PM into Tuesday……..


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



Beautiful Weekend with Springtime Afternoon Buildups….A Few Flurries during the late afternoon then a Fair and Warmer Sunday with still some build ups……Changes in the Pattern for Mid Week will bring Snowfall….

Monday AM:

No change to earlier thinking with the timing of the beginning of the precip into the high country early Tuesday evening. Snow Levels crash Tuesday night with snowfall accumulations good enough for a plow expected in the morning….then again in the late afternoon.

The big change is in the longer range, with the system for Sunday coming in earlier now and not splitting like before. The Sierra stands a good chance of a better outcome snowfall wise Sunday with another system hot on its heals Monday into Tuesday.  April Roars in like a Lion? ;-)


Sunday PM Update:

Some small changes in the short and medium range. IE it looks like a storm capable of producing a good foot of fresh now at the snow plot/main lodge.  The newer guidance beefs up the QPF up about another .25 by continuing the snowfall well into the afternoon now. So the crest may get between 15 and 18+inches now By Thursday AM.  I say plus, because;

1. There is a decent orographic component to the flow at 700mb up until the front comes through just before noon Wednesday, as well as the upper jet in the right spot dynamically earlier in the AM. That in itself, tends to give Mammoth more than what is expected over the upper elevations. Highs Wednesday near 40.

2. There is now at least one additional Vort Center that will come through in the afternoon Wednesday and the RH at 700MB is in the 90% range on the EC’s 12Z run at 2100z time. So although there may be a break in the action just after the front comes through, snowfall will pick up again fairly quickly in the early afternoon and continue through the remainder of the day. Snow showers will continue into the evening will less accumulation. Lows Thursday Am in the teens and 20s

3. This will be followed by the typical March instability (Cold air aloft/surface convection) which tends to keep the snow showers going another day, but light Accumulation’s only Thursday.  Friday looks partly cloudy w/flurries and milder.

The longer range; IE the end of this week, shows the energy of the short wave of interest next weekend, splitting south into Southern CA now. Although this is not entirely unexpected, the split may be big enough for little if any snowfall to occur in Mammoth Lakes the end of the month.  Lots of time to adjust though…..so for now, will play the wait and see and hope for the models flip back!!


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


An Upper High is Building in Central CA nicely today and will strengthen further bringing a warmer day tomorrow Sunday. There may even be a few flurries in the afternoon both Saturday and Sunday. These are not associated with any storm….Its just Springtime in the Sierra!

Looking down the road a few days ahead, the upper ridge will give way to a spring storm Tuesday night into Thursday. This is not expected to be a major storm….however, we may get 6 to 12 on Mammoth MT and some 3 to 6 inches in the residential areas of town. The snow level will begin at about 7000 feet Tuesday night,  than lower down to about 5500 by Wednesday. The heaviest period of precip will occur from about Day-Break Wednesday to about 12:00pm when the nose of a 105knot upper jet comes through Paso Robles….

The good news is that the pattern looks wetter after words with another storm by about Sunday with several more systems expected into April. If the Sunday storm on the 30th is not late, another inch of water is possible on the Mammoth Pass by the end of the month.

And…..The Climate Forecast System (CFS) has between 5 and 6 inches of water in the forecast for the month of April! Would that not be nice! For May, about another 1/2 to an inch! So the Spring looks wet by those numbers.


What the Dweebs are seeing is a persistent block over AK with a low pressure anomaly south of the North Pacific. The -EP/NP in April is typically a dry pattern here in the month of April in California. However the AO is positive and so the pattern across the US is going to be progressive and an excessive wave length should keep the short waves coming right on into California during the month of April.  As of note and of course at this time….The Sunday system next week looks like it is more of a mid latitude storm, and so Southern California may benefit more than Central Ca.

Dr Howard and the Dweebs…………………..:-)