Archive for August, 2017

More seasonal weather returns for Mammoth as drier air works its way into the sierra…..Isolated storms still possible through Wendesday then dry warm weather expected for the weekend…

Our air mass dried out Sunday after several days of rain.  Low pressure over Northern CA will keep a mainly dry SW flow aloft over the Eastern Sierra with only isolated showers and possible Thunderstorms through Wednesday during the late afternoon and early evening hours.  Daytime highs are season now with temperatures in the mid to upper 70s and lows in the upper 40s. The upper low over Northern CA dissipates the next weekend with higher heights returning. So the weekend of the 12th looks warmer than normal and dry with highs in the low 80s. Lows in the low 50s.

Weak Low Pressure West of Santa Barbara and upper ridge of high pressure over west NV Through Northern CA is Transporting Monsoon Moisture Northward through Central CA…..Increasing potential of rain this weekend….

The interaction between the upper low off shore and deep subtropical moisture will increase dynamics this weekend and the threat of wetting thunderstorm’s across the Mono County area, mainly Friday through Sunday AM. This mornings guidance showed a VT max or easterly wave coming out of AZ into SE CA. Showers and thunderstorm’s were developing with this circulation. This system will increase the threat of precipitation for the Owens Valley later today and tonight. This organized band may produce heavy rain.   The band weakens after midnight tonight but may still produce some showers after midnight for the Mono County area.


For the Mono County area, the odds for wetting rains will increase Friday afternoon into Saturday night……

As a note, Summertime patterns are different then Wintertime patterns as this is not a storm that moves in and moves out. Rather, there are convective parameters that are pointing toward an increasing chance of rain over the weekend. Morning cloud cover can inhibit the convective process and so that parameter will be looked at each morning as well to judge the days convective potential for the Mammoth area.

Of note, there is likely to be an upper jet that comes through this weekend to the south of us associated with the upper low off shore. This upper jet is likely to dynamically enhance lift over the sierra, sometime Saturday or Saturday night.


More later…………………….

High Pressure Aloft is cranking tonight with heights of 597DM over NW Nevada…Rare Easterly flow has developed with isolated storms moving east to west……SE flow develops Thursday as airmass modifacation continues….Moderate Monsoonal flow develops w/Increasing dynamics for Scattered Thunderstorms Thursday and Friday….

Showers and thunderstorms have been mainly isolated the past few days. The Atmosphere has for the most part been capped, so showers are occurring later in the day.  Tomorrow Tuesday and Wednesday the upper high will reach its peak intensity over Northern CA and Nevada with resort levels reaching its highs of the Summer. The Ridge will also take on more of a NW/SE orientation. As the cap weakens Thursday and Friday, dynamics increase and Monsoonal moisture moves up from the south. At the moment, the best convection may be west over the coastal sections of CA and interior deserts Wednesday night. Furthermore, for Southern Mono County, Thursday afternoon and night seems to be the main stormy period with storms strengthening at night! Will fine tune Tomorrow.  For the Deserts of Inyo and Kern County, Wednesday night may have some mesoscale convective clusters along with flash flooding. Trans-desert travel in this area Wednesday night will be very risky!


For you folks in Southern CA, get ready for some real humidity as PWAT reaches between 1.5 and 2.00 in some areas….More later…


The Dweeber…………..:-)