Saturday AM update:

The hottest dome of air of the Summer is expected to continue building today through Tuesday. A 600+DM at 500MB subtropical high builds into South Eastern Nevada with 600DM iso heights extending to the CA NV boarder Monday and Tuesday.  This is quite the heat pump. Upper Flow will be mainly SSE over Southern CA, so dew points will make it feel even warmer as compared to earlier in the Summer. And…the Circulation around the periphery of the anticyclone has the impulses well off shore, so no real trigger mechanism for any rain coming up from the south. in the medium range.

This is likely to be the peak of the Summer heat associated with the subtropical high. Later in the Summer and Fall Katabatic type systems with winds moving off shore could rival temps in the Fall, but with much less humidly. The Upper High peaks Monday and Tuesday so heat will build through then. Highs 105 to 110 in the Valleys of So-Cal are possible with an easing of the heat not expected until later next week.

In the high country of the Sierra and Mammoth Lakes, this particular pattern is associated with not only above normal temps, but in this case, atmospheric modification,  Moisture, now already in place, was aided by the remains from tropical storm Elida this past week. Recent afternoon convention has modified our air mass further with recent afternoon and evening thunderstorms. The high elevated heat source of the Sierra is notorious for this.  Often times, this is the Sierra’s natural cooler, as cloud cover will help keep those high temps confined to the low to mid 80s here. If this were early to mid July, we would be looking at low 90s.  However, without much of an afternoon Zephyr, lows at night will be mostly in the 70s through 9:00pm to 10:00pm, and may remain in the 60s through 1:00AM the following morning. . These mild temps are contingent upon no significant rain early in the evening.  As the Old Farmers Almanac says, these are the “Cat Nights” of the Summer!   😉


Dr Howard and the Dweebs……………………


The weather has been mostly copacetic this Summer with only short term heat waves and little in the way of humid weather.  That looks to change in the short term as a strengthening subtropical high works in tandum with a low pressure circulation off shore, This is expect to channel subtropical moisture from the remains of tropical storm Elida some 1400 miles south of the Channel Islands, late Wednesday afternoon. Subtropical cloudiness like altocumulus castellanus, was observed Wednesday, a sign of subtropical moisture aloft moving into Southern CA. Dew points were in the low 60s west of the Coast Range, 40s in the east San Gabriel valley and 30s in the high deserts. That will change over the next few days…

Dewpoints will be increasing the next few days….

For Mono and Inyo counties, 500mb heights are expected to rise to the mid to upper 590s DM.  This will challenge some high temperatures records early next week. The upper flow for the most part is southerly but at times southeasterly. This may tap monsoonal flow and initiate precipitation if there is some triggering mechanism. Too soon to tell, so the forecast called for mainly isolated TSRWs,.  Stay tuned if the models indicate some kind of upper jet or wave rounding the periphery of the upper high that will build north into southern Utah, next week.


Although moderate zephyr winds will blow during the afternoon and evening hours for a few day, they will weaken as the Thermal trof jumps the sierra to the west this weekend….


High in Mammoth in upper 70s Friday then low to mid 80s this weekend…..possibly mid to upper 80s early next week….


Stay Tuned…………………


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