Monsoon Pattern will likely culminate today and Friday as both drier air moves in and a more stable air mass arrives Saturday and Sunday…..However, another surge arrives Monday….

It looks like a couple of very active days and nights for both Inyo and Mono County as Deep Monsoon Moisture remains in place and at the same time, and even more importantly, the aid of the jet stream comes to play.

Today Thursday, The RT rear entry of a rather weak upper jet will provide added instability to our region this afternoon and evening. Tomorrow Friday, another upper jet, a bit stronger will provide added lift as we are under its Front left exit region.  Both of these jets adds to the more passive terrain driven convection that we experience during the Summer. At the moment, the Friday system seems stronger then today’s extra lift.  The NWS has Flash flood watches out for Mono and Inyo Counties today, tonight, Friday and Friday evening.

As a note, this pattern has the strongest Summertime forcing I have seen in several years!!

 

Highs in Mammoth Thursday will be in the 70s and Friday in the 60s.

Lows in the 40s and 50s.

 

Drier air works its way in for Saturday and Sunday.  It will be warmer…..

Rain chances are minimal and are mostly confined to eastern sections of Mono County this weekend

 

Another surge of moisture pushes in Monday. At this time, I do not see any upper jet support with it.

 

Dr Howard and the Dweebs……………:-)

Fair and Dry through Weeks End with slightly above normal temperature’s. A Monsoon Surge is expected early to middle of next week….

 

08/01/2022

 

At the moment, on the 850MB/ 250MB Lower Convergence/Upper Divergence couplet is developing West of Bishop over the Sierra then NE into Southern Mono County. Should be a very active day especially NE of that area.

Flash flood watch for Owens Valley Through 10:00pm TONIGHT.

Thunderstorms bringing Heavy rain are possible for many areas of Mono and Inyo County today and tonight.

Mammoth Lakes picked up .26 of and inch yesterday.

Highs in the low to mid 70s today lows in the 50s

 

There will be at least a chance of rain each afternoon this week.

 

Outlook:

The main monsoonal ridge will continue to push to the west and will be centered near the AZ border by Tuesday PM. By Thursday, the ridge will lift to the north and be centered near the 4 corners area, which will provide another opening of the door for a return of deeper monsoonal flow. Therefore,  an uptick on thunderstorm coverage is expected through Saturday. Temperatures will trend upwards midweek before cooling Friday again.

 

7/30/22022

The upper high that has been parked over Northern CA/NV will shift east over Utah by Sunday allowing a broad southeast to southerly flow, advecting moisture across our area tomorrow Sunday and Monday. An easterly wave now located over Extreme Southern CA will migrate NW through Sunday providing dynamics and both surface convergence and upper divergence through the Owens Valley and especially Southern Mono County. Outflow boundaries from storms from the afternoon will be the focus for newly formed thunderstorms into Sunday night. PWAT is approaching an inch over the southern portion of Mono County by late afternoon.  Heavy Rain with frequent lightning is possible as the day rolls on.  Campers and Hiker should be mindful not travel and camp near creeks, streams or rivers Sunday and Monday. Although Flash Flooding is some what rare in the sierra because of the watershed, The White Mts adjacent to the Owens Valley is very susceptible to FF’s.  The upcoming pattern for Sunday and Monday looks pretty intense for locally Heavy Rain throughout Northern Inyo and Mono Counties.  Drier weather will return by Mid Week.

High temps will climb into the low 80s today  but cool to the low 70s by Monday. Lows in the 40s are expected early next week. A warming trend set in Next Thursday.

 

Dr Howard and the Dweebs……………………..:-)

 

7/22/22 Update:

Big Pattern change this weekend over the Hemisphere as the upper low over AK retrogrades west while strong height rises occur into the GOA. This in turn will tug the Continental High over the desert SW West/North Westward, leading to a significant negative tilt continental high creating very good Monsoonal flow into Nevada and California beginning next week and beyond. Once the upper flow gets established, next to watch for is areas of dynamic lift!   Stay Tuned!!!  It could get pretty wet at some point later next week….

 

The Dweeber………………:-)

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WX Discussion:

A shift in the upper level winds from the SW on Wednesday due to weak troughing has scoured out what monsoon moisture there was yesterday. Our air mass will remain dry now through Monday with little change in temperatures. The fact that lightning will not be an issue, our air quality should remain clean as well.  High temperatures will remain above normal the next 5 days. However, a bit enhanced Zephier wind will provide breezy weather in the afternoons and evening to flush any hot air out of buildings with windows open!    Our WX is just perfecto!

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It been hot and will stay hot over the Owens Valley with little change in temperatures expected through next Tuesday. High temps will range between 100 and 105 and lows in the 60s in the north and 70s in the central and south. Winds will be light as well. Swamp Coolers work well in this pattern. However, as moisture increases later next week, it will become more humid and thus more challenging for those cooling systems by Wednesday or Thursday.

In the high country of Mono County, high temperature’s have been in the low 80s and will stay there through weeks end, with lows in the low 50s. Although it will be quite warm to hot over our region, no high temperature records are expected to be broken.

 

OUTLOOK:

Next week another surge of Monsoon Moisture will occur, beginning Tuesday and especially Wednesday and Thursday. This SE flow is likely to continue for at least a week or longer.  This is the period of time, not only Meteorologically but Climatologically that we will have our next best chance of wetting rains and Thunderstorms. Any heavy rains and or flooding will be dependent upon any dynamics/focusing mechanisms which may accompany. (So stay tuned on that)  The Dweebs will update later this weekend or sooner if necessary.

 

ENSO:

The updated IRI graphs shows high confidence that La Nina will continue through the Fall, then transitioning  to ENSO Neutral during JAN, Feb March 2023. La Nina Winters in Central and especially Southern CA,  has a dry bias. However, as we know from last December, it can be wet too.   An ENSO Neutral Signal for Winter 2023 might suggest that the winter months of 2023 could be surprising wet for CA.  Why?   The highest frequency of Atmospheric Rivers (AR’s) along the west coast occur during periods when SSTAs in the ENSO region 3.4 are between -05C and +05C.  Just something to think about.  🙂

 

 

Dr Howard and the Dweebs………………………….:-)

Monsoon Time….Where’s the Rain?……Drier later next week…..Warm weather to continue…

7/18/2022

 

Monday AM update:

 

Of note, dew points are on the increase from south to north over Inyo County this morning, as at the same time, temps are rising. PWAT’s ranges from, .75 to 1,00 over the Owens Valley. Additionally, mid level moisture is increasing and being fed by two areas, one over the Channel Islands to the south and more importantly an area from possibly an old Mesoscale convective cluster NW of Vegas/Pahrump. This area is advecting rapidly toward the Owens Valley.  Surface pressure charts keeping the thermal trof back more toward the sierra crest today for good surface convergence. as well. All in all, it looks pretty active this afternoon and again tomorrow with TSRWs and possible some localized areas of heavy rain. If you our in the open and hear thunder, take cover!

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It’s mid month July and time to look for thunderstorms and pattern’s associated with the Monsoon/Southeasterly flow.  As many know, late July and early August is climatically the peak of the Monsoon season here in Mono County.  Thunderstorms over the Sierra? There have been very few so far. However, you don’t have to go far to find them. They have been near the extreme southern portions of Mono County, near and west of Sherwin grade and especially over the Benton area, and along the White Mountains and especially Eastern Bishop, CA.

Why?   Why not Mammoth?

The position and strength of the continental high, east and south of us and its strength, in relation to any Trofing in the Eastern GOA and pacific NW, governs where the thermal trof sets up over the far west.  This is the plain vanilla pattern that is so common throughout the Summer here.   This Summer so far has been highlighted by weaker high pressure over the Great Basin and the Desert Southwest and stronger Trofing NW, and thus the thermal trof has been mostly over Nevada during the late afternoon when the best chances of rain occurs.  Don’t get me wrong, the Monsoon has been quite active over AZ, and as of late, Southern NV.  However, the Mono Zephier, has been quite strong too, developing strongly along the eastern slopes of the sierra, whereby the Mono County Convergence Zone is further east than normal so far. This zone shifts even further east to near the CA/NV border by Mid to Late afternoon.  As a result, the Mono County Sierra has been spared both rainfall and “Lightning” from TSRWs. So the upshot from no storms in the Sierra is no lightning caused fires too!

In looking at the GFS model Surface pressure/500 MB flow, the pattern is to remain static for the next 2 to 3 days. Thereafter, the trof strengthens off the pacific NW later next week for a drying trend along with a strengthening Zephier.  This diminishes the thunderstorm threat even further for the Mammoth area. As you may remember, the ECMWF from the month of May forecasted a wet July for the high country; its been wrong!

The Thermal Trof axis, or the axis of lower surface pressure and surface convergence is likely to remain east of Mammoth Lakes through that period. Bishop, Ca is much closer to that axis and so Bishop is likely to have better chances of rain and thunder the next few days.

For Thunderstorm lovers, there is still plenty of time calendar wise, for pressures aloft to build in from the ESE, and the Thermal trof to retrograde to the Central Valley, before moving over the Eastern Sierra for afternoon thunderstorms.

 

Stay Tuned!!

 

Dr Howard and the Dweebs………………………….:-)