Chilly Weekend to be followed by the potential of some significant snowfall Tuesday PM Through Wednesday AM……Cold Mid May adjustment wave over the far west is pretty much stationary through much of next week….The Dweebs will keep a weary eye on the Memorial Day holiday weekend……

Monday AM:

A Broad Trof remains over the far west this week with the upper jet west-east across Paso Robles to DV. Thus Mammoth remains on the cyclonic side of the upper jet. Several impulses will move through the broad upper trof the next few days allowing Rain showers and snow showers to occur. Some showers may be moderate with the potential for hail and accumulating snow mainly at elevations about 9K. A combination of deformation over Mono County, Upper Divergence/afternoon CAPE, will make for a potentially active late afternoon today…… This unsettled pattern is likely to continue off and on through this week.  The TOML may pick up an inch or 2  of snow over the next few days…At elevations above 8K

The Holiday Weekend is looking less active at this time with cooler than normal temps and isolated showers. High temps near 60 each day over the holiday weekend…lows in the low 30s. The Dweebs are still in the camp for the possibility of 3 to 6 inches of snow above 9000 this week…..Mainly Tuesday through Thursday AM…

Saturday Evening: 8:55PM

Like yesterday, temperatures ended up 20 degrees below normal for Mammoth with todays high of 45 similar to yesterdays 44. There was over 12 hours of below freezing temperatures last night, with lows in the upper 20s. The duration of the below freezing temps qualified for a hard freeze last night and this morning.  With the freezing level rising Sunday, temps will rise with highs near 50 at the Village. Most of the precipitation over CA has been under the cold pool over Northern CA. The short wave coming in this evening has little moisture with it. Nevertheless we might get a dusting or so over the upper elevations.  The long wave or west coast adjustment wave will remain in place over the California next week.  Individual shots of energy “are not storms” but impulses/Vort maxes that will travel down the coast then inland over the southern half of CA, during the first half of this up coming week.  This is all part of the same system that is bringing much colder than normal temps to our region, snow flurries in town and snow showers on Mammoth Mt.

The latest guidance from CRFC at 21Z today had the QPF of up to nearly 2/3rd of an inch beginning Tuesday afternoon through Wednesday AM over the west side of the sierra crest.  This particular strong vort max spins up to a closed center  “off the coast” all with in the same upper western trof.   The forecast for .63 looks good for 3 to 6 inches of snow at and above 9,000, mainly late Tuesday afternoon and throughout the night Wednesday.  The Dweebs will update on this short wave Monday to see how it is coming along…and will adjust for any change in amounts if necessary…….

Stay Tuned>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

The Dweeber…………………………….:-)

Expect a cool unsetteled week ahead with a slight chance of showers and thunder each period the next few days…..Temperatures will run below normal….As the Great Basin Upper Trof reloads and retrogrades….even more unsettled weather is expected over the weekend……

This mornings 5 day means from the ECMWF Control Ensembles showed a ridge at 140 west and a Trof in the mean over the Great Basin. A NW flow is occurring over CA with limited moisture. Strong Mid May daytime heating will destabilize the atmosphere enough for a “few” thunderstorms over Mono County. The track of an upper low over the Great Basin today is south….Then SW over Southern CA Tuesday. This gives the southern sierra the main focus of any thunderstorms action, especially Tuesday. It will be slightly cooler today and Tuesday. Highs in the upper 50s to near 60 in Mammoth with lows near freezing.

The weather pattern according to the 00z Monday European ensembles this week shows the upper high near 140west both retrograding and amplifying. This will retrograde the upper Great Basin low westward forming a rather deep low (for this time of the year) over the far west over the weekend. This upper low has been well advertised the past 3 to 5 day for next weekend.  The Dweebs expect the upper low to be preceded by wind Thursday afternoon into Saturday AM with Snow over the upper elevations and rain or snow in town this weekend.

It is too soon to forecast any amounts of snowfall on Mammoth Mt at this time.


The long range models keep the trof in the mean over the far west or far eastern pacific for a few weeks.


Dr Howard and the Dweebs………….


Nice weather week ahead with the beginning of the week offering seasonal temperatures, then above normal temps for Thursday and Friday……The weekend looks partly cloudy, breezy and slightly cooler…..Next significant upper low to effect the high country about the middle of next week…..

Tuesday AM:

Forecast on track with a little cooler day today. Some of the cooler air that dropped out of Western Canada last night will spread into the Great Basin, building surface pressures and providing for a gentle NE/SW gradient.  Any clouds that develop this afternoon are due to some marginal instability that will blow off from Nevada toward the sierra crest and may provide for a few isolated showers late in the day. Note; Any showers that may develop are not due to snow melt!   High pressure will build back in Wednesday afternoon for some warming, with a trend of warming through Friday. (Friday’s Highs Low 70s)

A weak trof with some cooling is still expected Saturday and Sunday. Highs Sunday in Mammoth in the low 60s


The Upper low that brought unseasonable cool and wet weather to the high country moved east last night, far enough east to allow for plenty of drying and lots of sunshine. Monday’s high should reach the mid 60s with lows tonight in the drier air below freezing….

Tomorrow, a weak back door cold front will kick up a little NE wind over the upper elevations. Temperatures will remain about the same as today. A little warmer weather can be expected Wednesday with much more warming Thursday and Friday. High in the low 70s.


The weekend outlook shows the bottom of a Trof moving through the sierra with the wet portion in the Pacific NW and extreme Northern CA. Expect the weekend to cool to the mid 60s with some high clouds and westerly breezes.


As highlighted above, the longer range models shows another vigorous Trof for the 2nd half of next week…  This may be similar to what we had, last week.


Dr Howard and the Dweebs…..