Mammoth Weather Outlook

Heat Wave Breaks as Tropical Rains this Weekend followed by Fall Weather later Next Week…

9-11-2022 Update

Yesterdays rainfall in the Mono County that began mid afternoon into the evening averaged between .25 and .50 with some amounts in isolated areas of over an inch. There were two areas noted for stronger storms. For Mono County was the area around Mono Lake. For the Inyo country area, Between Big Pine and Coso Junction west over the Sierra where stronger storms occurred over the elevated heat source of the Sierra.

This mornings WX 500MB maps still show the upper circulation of the remains of Kate west of Ensenada with the area near Oxnard in the favored NE Quad of Upper divergence and on going showers.  PWATS still in excess of 1.75 inch along the South Bay this AM. 250MB upper divergence maps have a few noted areas of upper divergence as well in those areas. (SPC)

As the Suns daytime heating resumes Sunday, Couplets are likely to develop in this NE quad. Included, along the San Gabriel Traverse range West Northward, thunderstorms are likely this afternoon. Although the remains of Kate will remain off the coast another day or two, and her residual moisture as well over Southern and Central CA, a westerly upper jet will approach Tuesday into Wednesday, providing both drying and cooling to the state mid week.  This will set the stage for a fair weather period with below normal temps toward weeks end.   Further cooling is indicated in the both 6 to 10 day and 8 to 14 day NWS outlooks. This will be a dry pattern.

Longer range from CVS v2 indicates warm dry weather after the 25th through the last week of Sept and 1st week of Oct.

PS, there is still an inside slider type trof dropping in around the Equinox that may bring a few upslope snow showers around that time.

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


As crazy as the weather has been with the heat, then rain, then cooler weather next week, the change coming up in the models later next week and beyond is just as crazy. This is because we are going to shift very quickly into a Fall pattern with even the chance of light snow around the equinox….. Oktoberfest, Lederhosen and Down Vests to prost with?


From KLOX early this afternoon….

TS Kay is now 240 miles south of KLAX and moving northwest at around 11kt according to the most recent update from the NHC. Models have generally trimmed back the rainfall forecast locally, though with PW’s still expected to be around 2.4″ and some other
indicators like the Extreme Forecast Index showing a heightened potential for heavy rain, so will stay the course for now with regard to rainfall amounts and the Flash Flood Watch. Still not seeing any lightning but the convective parameters are at least
marginally favorable for convection, mainly tonight and not so much Saturday.


More on the storms effects for Mammoth on Saturday…..


PS, if you follow the Old Farmers Almanac,  pick up a copy or online version for the Winter of 22/23. According to it, the Southern and Central Sierra is going to have a very big winter with lots of snow.  Usually that almanac talks from both sides of their mouths.   However, this time their really going for it!

Personally I just find it amusing and fun to read.  I for one am not a believer. 😉


The Dweeber

Hot Hot California in process with Tropical Storm lurking for next weekend for some rain and relief!

The on again off again and now on again threat for areas of significant rain in CA next weekend is in play. An accumulation of ensemble members are becoming for numerous for for just that option. In the meantime, hope must folks can get relief for the heat. Best places are at the immediate coast and in the upper elevation of the Mountains like Mammoth. Most other areas are in the upper 90s and 100s.
It was a 107 in Bishop Friday. More 105 to 108 temps seem likely through next Thursday. Thus more high temperature records on the way as very strong for September, Dome of High Pressure is locked in the next 5 days. Heights at 500MB as high as 600DM forecasted for this Tuesday-Wednesday over Utah and NV which may be the warmest days!! 597DM isoheights at 500MB all the way west to the Mojave Desert!

If this heat caused by the dome of high pressure remains strong and locked in over the west. The tropical system now forming off the coast of southern Mexico, becoming a hurricane by this Tuesday or Wednesday, off Baja will stay west enough to develop a South or Southwest upper jet, providing the lift for the moisture that would invade the state of CA. Timing….beginning about Friday or Saturday next week. This is likely to be followed by a major change in the pattern to one of windy and cooler weather with the chance of showers around the 15th or so..

The Dweeber………..

The Late Summer Heatwave of 2022 is in process over the state with hundreds of records expected to be broken….Models have backed off on on any significant rain chances for next week….

12z NAM 500MB Heights early this morning had the center of a developing continental high between Mammoth and Stockton with the Progg shifting the upper center over Eastern NV later today. Heights continue to rise as do surface temps. By around noon Friday, the center is near the NV/Utah border with 500mb heights well in excess of 594 DM. A short wave Trof pushes into Northern Ca and OR Friday night bringing a bit more Zephier to Mammoth in the late afternoon and evening. However, this feature actually build 500MB heights higher in excess of 597DM Saturday over Western Utah, then shifts it west to our Eastern CA Mono County by Late Sunday Afternoon. As an average, the upper anticyclone is mostly over NV, thus acting as a shunt from allowing the southerly flow of deep moisture from reaching the sierra. Thus the dry weather is likely to continue for quite a while.

Expect Highs in Mammoth in the mid 80s this weekend though Labor Day, lows in the low 60s.  Expect Zephier winds between 10 to 20MPH each late afternoon and evening….

The longer range for the following weekend is questionable as the models differ on how quickly the pattern actually breaks down. Latest is that the GFS has a cool Trof pushing in to the Pacific NW next Wednesday increasing Zephier winds in the high country and bringing the beginnings of a significant cool down, during the second half of next week.


Stay Tuned…..


Dr Howard and the Dweebs………………….:-)