Airmass modifacation underway with an increase of afternoon and evening thunderstorms through the weekend….Saturday afternoon and Sunday look particularly active…

Air-mass modification is underway with wetter afternoon and evening thunderstorms expected through the weekend. This is due to the east west upper ridge over California earlier in the week that has settled southeast over the four corner states. There is an “Easterly Wave” that will move up through California this weekend increasing instability, mainly Saturday afternoon into Sunday. That period seems to have the potential to be the wettest this weekend.
Otherwise, the weekend will be a bit cooler with the added moisture as afternoon cloudiness will develop earlier, blocking sunshine. High temperatures will cool to the 70s this weekend, nights will still be in the 50s

Excerpt from WSFO RNO discussion:
Atmospheric moisture will be on the increase through the weekend so storms will become quite wet and capable of producing heavy rainfall. There will be flash flooding concerns due to potential training
storms, ample moisture, and increased instability. Despite all this, dry lightning strikes outside of the rain core could still potentially ignite new fires but a widespread dry lightning outbreak is not expected.
Thunderstorm coverage is likely to increase Saturday into Sunday with upper level waves potentially contributing to nocturnal thunderstorms Saturday night and Sunday.
Both Saturday and Sunday look to be particularly active with the main threats being flash flooding, hail, and abundant lightning.


Dr Howard and the Dweebs………………………:-)

Very Warm Weather returned to the high country Tuesday with Wednesday the peak in the heat….East West Ridge to slide Eastward Thursday with Southeast flow returning for more afternoon and evening thunderstorms…..

Thursday July 19th Update:

Very Warm temperatures expected for the high country and Owens Valley next week with possible high temperature records Mid Week….


Wednesday Temp Update:  Hi Temperature in Mammoth was 88 degrees Wednesday.  This was the warmest day of the Summer so far and the climatically warmest temperatures of the year.  So if it does not reach 88 again or warmer this year, Wednesday would have been our climatic warmest day.


It was a very warm day Tuesday with a high in Mammoth of 86 degrees.  The models show an East West ridge which has kept the atmosphere capped with little convection in the afternoon other than a brief isolated thunderstorm over the sierra Tuesday PM.  Todays weather will be the warmest for the High Country and Owens valley with a high again near 106 expected in Bishop. The Upper high at 500MB reached 598DM over the top of Bishop yesterday and will remain there today. By Thursday AM, it slides SE to St George Utah. As it does, an easterly wave develops in its underbelly, which provides for air mass modification and good SE flow up from the deserts of SE CA and SW AZ.   The result will be a rapid increase in thunderstorms Thursday afternoon into the night.   With 700mb moisture in place, mainly diurnal afternoon and evening thunderstorms will continue into early next week. Not too sure how moist it will get by this Friday.  Will follow the PWATs and report later…  Plan on afternoon convection each and every afternoon beginning Thursday…


Next week:


The GFS and ECMWF and Canadian have differences in the strength of the continental high over California early next week.  The GFS is trying to bring a record heat wave over the southern state while the ECMWF has it warm but no records…..There has been some mention from forecasters that there has been a bias in the GFS to make it too hot.  Well see soon..  The 06Z Wednesday GFS has a large scale scorching 600DM high over Southern California Tuesday night. Both the Canadian and ECMWF are both a bit weaker with this upper high and further east.

Winter seems so long away!


The Dweeber……………….:-)

A very moist airmass will continue for the Eastern Sierra Friday, with slow drying Saturday through Tuesday with a warming trend….Another surge of monsoon moisture seems in the cards the second half of next week…..

It was a wet afternoon and evening Thursday in Mammoth with moderate to heavy rain in many areas that continued into the night.  Mammoth at the Village picked up .32 of an inch of rain while the Mammoth AP picked up .41.  Bishop’s precipitation was the most noteworthy with precipitation totals of 1.44 inches for 48 hour amounts for the days of July 11th and 12th. Not only was this a record for the dates but the consecutive two days combined were the wettest two days in any Summer at the Bishop Airport in 120+ years.

Fridays forecast is problematic as the sky’s are over developed this morning. This means that unless we get a few good hours of sunshine, the possibility of heavy rain is greatly diminished. So here we have a situation where areas of heavy rain will be focused only in areas where there is ample sunshine that creates good heating as there will not be much movement in the storms today.

High temps will be in the 70s today with lows in the 50s. If we do not get any meaning full sunshine today Friday, highs may only get into the 60s.

Focusing upon the synoptic pattern;  shows the beginning of a drying trend Saturday through Tuesday with Tuesday being a dry sunny warmer day with no precip in the forecast. Even through dew points are expected to be on the wane the next few days, added sunshine and heating may give a boost to rainfall, although lighter amounts. This would be especially true Saturday before enough dry air gets in the mix. Sunday and Monday shows just a chance or a slight chance of thunderstorms….Tuesday looks dry and warm.


Longer Range: Period 19th through 24th

High pressure will begin strengthening Sunday and especially Monday and Tuesday. However, over the central and southern part of the state, this will also act to suppress convection over the Eastern Sierra while temperatures soar to the mid 80s at resort levels and 105 in Bishop by Tuesday and Wednesday.

The Global Forecast System has the continental high strengthening to the east of Eastern California near the 4-corners states by Wednesday night. there is a good chance that the gates will open once again for Monsoon Moisture and Airmass Modification beginning Wednesday night and especially Thursday and Friday. This would redevelop a thunderstorm pattern once again prior to the following weekend. Thereafter, the GFS global model builds a 600+DM upper high at 500MB over the four corners states with the possibility of deep moisture.  With its outlook for the 600DM ISO height at 500MB pushing well into Southeast CA, extreme heat would develop again for Southern California Sunday or Monday and into Tuesday, around the 23rd of July. This pattern may bring a return of the 115 degree heat many inland valleys near the Downtown LA with 110 possible just inland from the coast..  Note: This is just an outlook and is subject to change this far out.


Dr Howard and the DWEEBS…………………..:-)