Major Storm developing by Mid Week with Subtropical Connection….Heavy snowfall and strong winds over higher elevations with Colder Portion of Storm expected Thursday….Several feet of new is expected over Mamoth Mountain by Next Weekend Then….???

After a break in the storminess Saturday, Sunday on into Monday,  winds will increase again Tuesday with light precipitation developing as early as Tuesday mid day.  There appears to be a weak AR that becomes quasi stationary early Tuesday evening and possibly stall through Wednesday over the Central Sierra. So the High country remains in the warm sector Tuesday afternoon, through much of Wednesday.  It is not a wide swath and not a particularly wet one. However, it just appears to stall in the vicinity of Central California. This was in both 18z, 00z and now 12z Monday’s GFS runs.  The upcoming pattern is an interesting one in that it has a very good moisture tap and is accompanied by a surface wave that spins up into a closed cyclone, in the sweet spot, west of Pt Area. If I had ordered it myself I would not have changed its location much for Mammoth Lakes.  With the snow and the freezing level falling Wednesday and Wednesday night, the snow that will be falling on Mammoth Mt Tuesday and Tuesday night will change from rain to snow in the Towns of Mammoth and June Lake, during the day Wednesday. The “IOP” with this storm will be Wednesday night into Thursday. Amounts in the Town of Mammoth may tally between 1 and 2 feet by Friday AM at 8000 feet…..3 to 4 feet on Mammoth Mt over the crest.

There is another storm for the weekend that is colder with 1000-500MB thicknesses south of 540DM by Saturday Morning. The new 12Z Monday GFS is more bullish and a bit quicker with it.  This storm may prove to put a lid on our high temps Saturday into the 20s with snow showers possible even in the Owens Valley, Saturday morning, especially western sections near the sierra foothills….it will be cold and breezy!

 Longer Range:

The differences in the global models are more profound during the week two period. The ECMWF wants to fill the Midwest and eventually east with Arctic Air. That will tend to weaken storms moving into the west coast or cut them off all together. The main differences considering weeks 2 and 3, are in how fast the cold air moves out.  The GFS is much more progressive than the ECMWF and so it flushes out the cold quicker, while the EC takes more time.  What may end up is a more southerly but weaker storm track that favors Southern CA more… week two.  By week 3, “Mid-December, the storm track should favor the west coast once again and on into Christmas.


Dr Howard and the Dweebs……………………:-)

Storm Door Opening first time since last Spring as Moderate Precipitation Producer Approaches….Snowfall expected later Wednesday into Thanksgiving day…..Then a windy system with unsettled weather expected Friday/Ngt…..New storm expected by Mid Week……..

Sunday 1130am…


The Dweebs are traveling today….will update Monday morning. However, get ready for a massive storm midweek. Three feet + over crest.

The week 2 forecast looks potentionally omanious as well…..MJO is strengthening in phase space 8 into 1 late this week and next, leading to The potential for a strong negative phase EPO week two, then strong AR potential for west coast.




12:50 PM Wednesday


The Euro has come in wetter late this morning for Friday for our area. It still shows most of the moisture/precip on the west side. However, I am beginning to think that the upper mountain may pick up another 5 to 10 inches of sierra cement Friday/Night. There will still be a lot of shadowing for points east of the crest and so the QPF will fall off pretty quickly. The EC QPF for the town is between .25 to .40 now. But the snow level will rise to 7500.  It certainly possible that elevations from the Village at Mammoth to Canyon could get 3 to 5 inches of wet snow Friday and Saturday. Of note…the hose is a very wide one. What is strange is that the upper polar jet is NW/SE. over OR and the subtropical jet is leaving Southern CA… Weird!!! What’s generating all the PW?  Typically, we do not get this kind of PWAT from a NW upper flow. The Atmos  must be doing something else at lower levels? Anyway, with the bulk of precip is still on the west side. It will be very windy along Highway 395 Friday afternoon. Might be difficult to get flights in and out?  There may be some wind related road closures as well for high profiles Vehicles, due to the related gradient downsloping from the precip on the west side.  Again it will be interesting to see how this all plays out.

 Longer range:   

The Euro is down playing a major AR for next week with the Tuesday system, so although it shows an AR,  it is nothing unusual, again according to the ECMWF today. The GFS?? Its gone bonkers….Death and Destruction.  To embellish…you will be able to smell   Bananasbreadfruitscoconutsmangoespineapples, wild apples, star fruits, papayaguavasour sop, you name it if it verifies.  I do not believe it at this time so just enjoy the dream.  🙂

If the Euro starts to sing the same tune….Northern Californians may need an ARC by the following weekend.  Again, this is one operational run, I do not believe it…

One thing worth mentioning that supports the GFS;  “The MJO”

In the meantime have a nice holiday!


Short term models continue the timing with Tuesday nights runs in bringing a moderate snow storm to the Sierra Wednesday night into Thursday AM.  The Town of Mammoth is expecting up to a foot of snow while the upper mountain 18 inches+.  Daytime highs will cool to the 30s in the Town of Mammoth Thanksgiving day with 40s expected over the holiday weekend. In the storms wake is another system that will bring much more wind to our area Friday into Friday night. The Upper Jet favors the Northern Sierra most, and so a lot of the precipitation will not make it very far over the Sierra Crest. Because of this feature, snowfall amounts are going to be very difficult to estimate. Upper elevations may pick up a few inches to 1/2 foot while the Town of Mammoth may not see anymore than snow or rain showers. The warm air advection pattern associated with this system will force snow levels to rise up to 7500 feet by later in the day Friday then down over night. Overall, this is a system that Colloquially will bring 6 feet of wind and maybe a few inches of snow…Maybe not….The main focus of the weather system will be the west side and especially the northern sierra west side where up to 3 to 4 inches of rain may fall in a few areas.  The remainder of the weekend looks dry beginning Saturday afternoon into Monday.


Having a glimpse of mothers natures face through the American models, she definitely has that twinkle in her eyes for later next week. .  However, at time, it is too far out to go to the bank on it…..Will update Monday morning……

Happy Thanksgiving to all from Dr Howard and the Dweebs…………………..:-)

Winter Storm Warning Hoisted for Mono County…..Pattern Change over Eastern Pacific continues with a few more nice days ahead before 1st Winter Storm arrives later Wednesday…..Moderate amounts of Snowfall Expected Wednesday night through Thursday…..Some light wet snow will follow Friday….with some Snow Showers possible Saturday……Sunday Looks Fair…..

4:00PM  Update

Storm has slowed a bit with WSW now set for 6:00PM through 6:00AM Thursday

Via NWS; Moderate to occasionally heavy snow expected. Total snow accumulations of 6 to 14 inches above 7000 feet, highest west of
Highway 395. Up to 4 inches is possible between 6000 and 7000 feet, with little or no snow below 6000 feet.

Mammoth Crest 18 inches+

Still looking a small storm with light snowfall and windy conditions Friday/night



Quick update:

No changes to the forecast. Timing still looks good. See the NWS Winter Storm Watch in the hyper-link below. The forecasted storm totals show 4 to 8 inches in the Town of Mammoth with up to a foot near the Village and Canyon Lodge.  Amounts over the Upper Mountain by Thanksgiving Day may equal 18 inches or more.  The next weather system for Friday Through Saturday morning favors the Northern Sierra. It is a windier storm with light amounts of snowfall expected over Mammoth Mt.  (Up to 5 inches) 1 to 3 inches in town. The snow level will rise through the storm until Late Friday night when the freezing level falls briefly then rises again between Saturday afternoon and Sunday. This is a storm with warm air advection. Not your typical cold front. Highlights are wind and light precip.

The Dweebs are watching the next WX system for near the end of the month. There may “Possibly” be an AR with that system. Stay Tuned!!!! The American operational 12Z GFS had an 180 knot westerly Jet at 250MB with its axis W/E across Northern Central California.  I am not jumping on this one yet as the ECMWF is not in agreement at this time. This mornings GFS model run would certainly be WINDY,  Wednesday afternoon the 28th through Friday afternoon!!  If this model verified, this could be one of those Crowley Lake Wind Events.  Those that have lived there long term, know what I mean….  So again this “is not” a forecast…Just something to keep our eyes on!!


Dr Howard and the Dweebs………………….:-)



NOTE: From the Yosemite NPS;

Tioga and Glacier Point Roads will close at 6 pm on Tuesday, November 20.  Tioga and Glacier Point Roads will close at 6 pm on Tuesday, November 20. The Tioga and Glacier Point Roads will close to all vehicular traffic beginning at 6 pm on Tuesday, November 20, 2018 due to incoming winter weather. The roads will reopen as weather and road conditions permit. This is not necessarily a seasonal closure.


By far the best weather system to begin the Winter Season here in the high country will move into Southern Mono County later Wednesday Afternoon with snow levels rising to 6500 as winds mix out valley inversions of cold air.  However, snowfall will begin earlier on the west side resulting in pass closures well before that time. For those that this is important to, be sure to check with Caltrans Tuesday before departing and remember that Caltrans may close the passes earlier than expected. I have had to make that long trip north on highway 49 to highway 50 after being disappointed by an early pass closer……:-(

Both today and tomorrow Tuesday will be fair days with variable high clouds and highs in the upper 40s. Winds will pick up over the upper elevations early Wednesday morning with increasing clouds and snowfall in the high country during the day Wednesday. The heavier snowfall is likely to begin after 6:00PM with moderate snowfall all night under good UVM. The first wave will be through about 5:00AM Turkey day with another UVM max around 10:00AM. So periods of moderate snowfall are likely through about 12:00PM Thursday. Lighter snowfall will continue the rest of the afternoon. There is another short wave on Friday that is not nearly as impressive as Wednesday nights storm. The snow level will rise with that system up to about 7500 feet. There is a small AR with it that will mainly affect the west side of the sierra and so the sierra crest may do much better than areas to its east. Nevertheless, some 2 to 6+ inches is possible with that system.  The thinking this morning is that the upper mountain is still in for about 18 to 24 inches by weeks end. The Town of Mammoth 6 to 10 inches. The Dweebs will update the QPF Wednesday AM when the HRRR 3K is out.

For the Travelers heading to the high country….There is likely to be Chain Controls at some point Wednesday night so plan accordingly. Sunday appears to be a good travel day on your return….. High temperatures in Mammoth for the holiday and weekend will range in the 30s and low 40s with lows in the teens and 20s.

Have a Great Thanksgiving holiday weekend!!!!