9:15 AM July 4th:

Breezy weather on tap for this Fourth of July with seasonal temperatures. Expect highs in the mid 70s today and lows in the 40s  Gusty SW winds and low humidity in the afternoon and evening hours will create critical fire conditions. Be especially careful with fire.  Subtropical ridge in the east is still forecasted to retrograde under the pacific NW Trof.  In doing so, hot temperatures are forecasted to develop over the Eastern Sierra this weekend. Initially the air mass will be dry. Over time next week,  isolated thunderstorms will develop early next week. As we go into the following weekend the subtropical continental high will develop near the four corners states which completes the seasonal transition to summer pattern climatically.  With the westerlies fully retracted back up into Canada and the upper Trof in the mean lifting out off the Pacific Northwest coast,  early next week, the Continental High will be able to set up for a prolonged period of time. I expect this feature to become negative tilt later next week which will allow for South or Southeast flow to develop. This usually is associated with deep monsoonal flow over the Great Basin, Desert Southwest and areas of the Far West. Easterly waves, Vort maxes from subtropical disturbances may be the trigger for strong thunderstorms developing over the greater Eastern California area as we approach the weekend of the 13th and beyond. Of note, the GFS has been consistent in developing the dreaded 600 DM high at 500MB  over the Utah/Colorado border about the 17th. If that verifies, deep monsoonal moisture will invade the Far West with possible areas of heavy rain in the usual favored areas.  Along with the rain will be humidity. and possible areas of extreme heat over the west that are absent in cloud cover. One again, it will be Towns like Mammoth Lakes and June Lake that will offer the best relief for the heat.


El Nino is developing rapidly and may reach a strong threshold of +1.5C in the Nino 3.4 region by November.  This raises the possibility of a wet Fall here in Mammoth and an early start to the ski season. September may be wet as well with Hurricane remains effecting Southern CA and the Southern Sierra.


Happy July Fourth!!!


Dr Howard and the Dweebs………….:-)


The Northern and Central West Coast continues to experience the remains of the upper jet left over from the winter of 2018. This is evidenced by the Eastern Pacific Ridge parked out along 130west and the formation of yet another digging Trough over the pacific northwest this Tuesday and another short wave that will carve out yet another Trough further west on the Fourth of July. Both of these weather systems will bring wind and more smoke from the Lion fire eastward, as FS burn out provisions accelerate the consumption of available fuel within the fire area.

According to both the GFS and ECM models,  week 1 and 2, this should be the end of the upper jet into the central west coast as the subtropical ridge over the east, retrogrades westward and dominates the far-west by Week 2. This will also initiate the AZ/Mex Monsoon or seasonal wind which is climatically favored the middle of July for the southwest and Great Basin. So enjoy the last of the dry weather the next 6 to 10 days with only isolated TSRWs, then get ready for Summertime’s finest displays associated with SE flow by Mid-July!

In the meantime, expect a little cooler days beginning this Tuesday into Wednesday with gusty afternoon and evening SW winds up to 35 MPH. Daytime highs will cool from the low 80s today Sunday, to the mid 70s by July fourth, then 80s returns by the following weekend. That following week looks very warm with SE flow developing along with the increase of areal coverage of thunderstorms throughout the sierra later week 2.


Dr Howard and the Dweebs…………………..:-)