Monday Night; August 31st.

All systems go for excessive heat event for California….

Quick look at new GFS 00z Tuesday Sept 1st, shows the same ugly 600DM at 500MB upper high over Nevada Saturday afternoon and it stays right around that strong through Sunday PM.  850 MB temps warm through Sunday.  The upper high weakens slightly early next week with its core shifting westward over Central CA by then.  High temperature records are definitely in Jeopardy this weekend into early next week. For the high country, the good news is that because it will be September, the lows at night will be cooler!  50s…

Highs in Mammoth will be in the mid 85 to 87 this weekend; lows in the 50s. Expect little change in the temps fr the high country Labor Day.


Bishop high temperature records this weekend are 103 Friday, 103 Saturday , 103 Sunday, 100 Monday  These were set in 1955. Bet some of these will be either tied or broken.


Dr Howard and the Dweebs…………………..:-)






Pretty typical weekend shaping up with isolated thunderstorms in the late afternoon and early evening hours. Highs will be in the mid to upper 70s, However, the lows are cooler now because of the drier air and longer nights as they are down to the 40s.  We have another heat spell setting up for CA. “Possibly”, not quite the strength as the one a few weeks ago, but one that may break records for the dates around Labor Day. 500MB heights may reach the upper 590s dm over California next weekend as that ugly 600+DM anti-cyclone sets up. This pattern is more interesting to me.  It is one that combines western hemispheric amplification with an extension of the Eastern Pacific high in the Gulf of AK SE over CA.  A quasi polar vortex is part of the pattern developing over Central Canada. So initially its the ridge over CA then the Anticyclone that develops later in the period around Labor Day.  Mid to possibly upper 80s now expected over the Labor Day holiday weekend in Mammoth, 100s in Bishop and 100 to 115+ in the valleys and coastal plain of CA, as desert air returns to the coast. Later in the pattern around Labor Day, isolated thunderstorms may develop. This is not a pattern that typically brings a lot of humidly to CA as the pattern evolves from the NW.  However, latest 12z GFS from 8-29-2020 does show a strong surge of PWAT (1.00 to 1.50) up the CA coast the send half of next week. So a lot will depend upon of the upper flow is easterly or south easterly. This new pattern once again, will be of major concern to fire weather experts….. Latest temperature departures suggest 15 to as much as 30 degrees above normal during the Labor Day holiday weekend from Oregon to Southern CA.

Again….The big difference of this pattern to the one that developed a couple of weekend ago, is that last time, a continental high set up along the Southern NV Utah border and 500MB heights were in the low 600s DM.  South-South East flow developed and the Vort train extended during that famous weekend, from southeast to northwest along the coast of CA, setting off a spectacular thunderstorm complex,  This pattern will be different as the upper high is progged to develop as part of the eastern pacific high pressure complex in the north pacific. A closed anti cyclone is progged to set up near Mammoth Lakes or Western NV at times. Easterly flow over Southern CA. will drive hot desert air westward to the coast. As the pattern evolves, there is some suggestion that a mega 600+DM at 500MB bubbles up over the far west.  It will be very interesting meteorologically…


Dr Howard and the Dweebs……………………..:-)