Wind Shift has flushed out most of the moisture……However….Smoke from the west side has reached Southern Mono County…….Major Easterly Wave trending more west and north now….With Odds Increasing for Heavy Rainfall and potential flash flood conditions for the Owens Valley Sunday/Night…..Mammoth now included in this watch so stay tuned….
Thursday July 31, 2014
Posted at 4:54 pm by Howard
Quick Update: Sunday AM Wind shift has pushed smoke back to west side….
This will continue for the next 36 hours…
Rains will begin either later this Am with more certainty this afternoon.. I do hope that Buddy Guy gets done by that time….. but that is dubious at best..
Deeper Moisture is working northward from a pool of about 2.00 PWAT Along the coastal section of Southern CA. It is interesting to note that the air mass over Southern CA is almost as saturated as Central Florida! And worth mentioning is that although all this moisture is around, not much in the way of rainfall is expected for coastal areas of Southern CA. That is because the atmosphere is not dynamically induced. Areas to the northwest north and east of LA it is a different story where convergence/divergent couplet is in place. IE Right entry region od upper jet at work…
The upper low is expected to stall out over CA/NV the next several days so it looks quite wet with periods of rainfall. Tonight….most of the night will be wet with rain. Campers be aware of that….
Today will be a slightly warmer day than Friday:
It will be partly cloudy with areas of smoke and even some denser smoke as the French fire in the San Joaquin drainage continues to burn out of control. It has now reached about 12,000 acres and is 15% contained. Some from this fire will affect the eastern sierra on and off now well into August depending upon wind direction. An Easterly Wave will move into the high country Sunday afternoon with Showers and thunderstorms. This system is likely to produce rain throughout the night. Some thunderstorms could bring potentially heavy rain depending upon the amount of daytime heating we get early in the day. This is an organized area of moisture and precipitation that is moving up from Baja today. Upper level moisture has already reached the deserts of Southern California. The trajectory is right up through Eastern Ca Sunday/Night. The silver lining is that it will most likely disperse the smoke for a while….. The Owens Valley is under a flash flood watch beginning 5:00am Sunday morning. Campers, hikers and outdoor enthusiasts should stay in touch with advisories that will be forth coming later today and tomorrow…..There is the possibility that the Flash flood watch for the Owens Valley may be extended north to include Mono County for Sunday as well.
I will have an update on this developing weather system Sunday AM………
Dr Howard and the Dweebs………………………………..:-)
Friday AM Update:
Light North East Flow has suppressed smoke back to the west side of the sierra for the moment. This will change as the prevailing winds are from the SW…..and as the daytime heating occurs, the smoke from the west side will roar back into the Mammoth area this afternoon. It will be smoky this evening as well with a slight chance of Thunderstorms this afternoon and evening. Smoke from the fire on the west side will continue to move back and forth periodically.
There is an area of disturbed weather (Easterly Wave) over the Sea of Cortez that will move up into Southern CA later today and make its way into Southern Mono County later in the day Sunday. If it does, we’ll not have to deal with smoke. However we may have to deal with rain and thunderstorms beginning later in the afternoon Sunday and evening. This is the type of weather pattern that does not clear up after sun set and so rain is a good possibility Sunday night as well. The system in the models has been trending further north in the most current guidance. This would bring heavy rain producing thunderstorms to at least the Owens Valley and Southern Sierra with Flash Flood potential in some areas. It will more then likely bring rain to the Mammoth area as well….
The Dweebs will keep an eye on this system and model trends…
Now a special edition from Toms Corner….
Models showing enough instability today ie(CAPE,LI) along with low level convergence and weak upper div along Sierra crest for another day of afternoon TSTMS. Many of these storms may drift or reform further E with late afternoon zephyr. Saturday looks to be dynamically suppressed and to stable for TSTMs especially northern Sierra where NVA and pos LI forecast. Could see isolated activity srn Sierra and Whites with lingering instability and better forcing. Things get very interesting by Sunday as several weak vort features or easterly waves along the srn periphery of 4 corners high consolidate with another vort center west of NRN Baja to spin up a larger vort max which tracks nwd into Srn Sierra and srn Nv. Its interesting to watch the rr (right rear ) entrance region of the 200 mb jet and its associated 250 MB Divergence as it expands nwd and intensifies on Sunday. The 200 mb jet max goes from around 50-60 kts over srn Utah today to over 80-90kts in srn Idaho Sunday. I believe
this is a result of convective feedback spinning up stronger vorticity and jet speeds as the models indicate. You can see the H5 vorticity centers and 200 mb jet to north become stronger as more convection developes over Srn AZ and SRN CA. The question again will be if the extensive cloud cover on Sunday will allow widespread deep convection to develop or will it just be overcast with rain and a few embedded Tstms. Or will there be enough dynamics (DIV/CONV coupleting) to produce enough UVV to overcome the lack of solar heating. High PW airmass with sufficient CAPE and relatively slow storm notions from south for locally heavy rainfall and high flash flood potential if/when anything gets organized Sunday and possibly into Monday. Stay tuned
Retired Leed forecaster
Light WSW flow in the lower levels has pushed smoke from the west side of the sierra over the pass and into Mammoth. It appears that it will be a pretty smoky night up until about 11:00AM Friday morning. By the afternoon some improvement is expected until the evening hours. We will have variables amounts of smoke now until the return of the southerly flow. That appears to happen later Sunday as the upper flow backs to the south again into early next week….
An update in the morning……..