Archive for July, 2013

Upper High over Nevada to Weaken Today Allowing Moist Upper Flow to finally move North through the Central Sierra…..Showers and Thunderstorms a good bet the next few days……

Tuesday AM Update:

NWS Hoists Flash Flood Watch for both Inyo and Mono County’s:

Campers, Hikers and Fisher folks keep your eyes on the weather today. Be aware of your surroundings and stay away from areas prone to flash flooding. IE Canyons, Arroyos, creeks and stream’s. If heavy rain is observed upstream get to higher ground.

Latest 12Z WRF has very slow moving VT Max along the Inyo/Mono County boarder ATM….shifting NNW so far.  PWAT chart has rich isopleath of 1.8+ over Kern Co/Inyo Border with gradient right up the Owens valley and Mono County. CAPE in our vicinity is near 750 Jewels per KG. IE AIRMASS is Very Buoyant with convergent/divergent couplet 

Main message is for areas of very heavy rain today. Travel on roads between Eastern Ca and Nevada through areas “like” West Guard pass/Lida Junction will be dangerous this afternoon due to potential for Flash flooding. Additionally, areas along the Sierra in historically flash flood prone areas will be the same.

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Another very warm weekend has come and gone as an area of strong high pressure acted to break more high temperature records as well as develop mainly air mass showers and thunderstorms. This mornings guidance is a bit different as the upper high that created another high of 105 in the Reno area for the 4th time this Summer…and upper 80s in Mammoth is breaking down.  The strong easterly wave that moved out of AZ and into Southern Ca over the weekend is now associated with an area of low pressure off the coast of Baja. To its NE is PWATs in the range of 1.5 to almost 2 inches.

With the upper high over NV breaking down, monsoon moisture and dynamics are being allowed to move north and invade Eastern, Ca , Southern Ca , the Southern Sierra and eventually up through the Central Sierra later today.  Vandenberg, sounding was over 1.5 Pwat this AM.  A vort max near the coast of south-central Ca was enhancing shower activity near Paso Robles this AM.  A Divergence/Convergence couplet was located over the Southern Sierra at 1600UTC.

Flash Flood Watch’s were issued for portions of White Mts adjacent to the Owens Valley Today. Scattered TSRWS were in the forecast for the Mammoth area…..with the action going possibly into the night tonight and continue Tuesday.

If you are camping and or hiking be sure to keep an eye on the weather this week for the possibility of heavy rainfall in the Sierra.

High temps will not be as high the next few days because of more cloudiness and moisture. Nighttime lows will be higher…..

 

 

The Dweeber………..

Near Record Highs Expected the Next Few Days before Airmass Modifacation Increases Moisture and Rain Possibilities Later in the Weekend and into early next week…Drier More Comfortable Weather to Return by Midweek Next Week….

 

The high temperature reached 83 in Mammoth Wednesday as heights increased once again over the far west leading one to believe that that the Summer of 2013 is looking to be quite the warmer then normal Summer.  With that said, Thunderstorms so far have not been that all impressive right here in Mammoth thus far. That may be ready to change as an increase in Monsoonal moisture in combination with air mass modification this weekend will provide the juicing for some rainfall, beginning Saturday then more likely Sunday into Monday.

The Weather maps this morning were highlighted by high pressure aloft over Nevada bringing on the heat with an inverted trof over northern MEX and (easterly wave aloft) centered near the MEX/NEW MEX/AZ border tracking westward. This should help the flow turn more easterly for an influx of moisture and eventually some spokes of dynamics into Southern Ca and possibly up into the Southern Sierra as well. Thunderstorms will spread westward into Southern California deserts Later Friday and into Saturday. The European model is being favored through Monday showing a weakening upper high later in the weekend and the aforementioned inverted surface trof shifting into Southern California. SSTS are running into the high 80s in the Northern Gulf of Ca. A Gulf Surge associated with this Inverted surface feature is certainly possible. The Southern Ca deserts as well as Southern NV could really get walloped with some heavy rain and flash flooding in some areas by the end of the weekend or early next week. It will feel very humid along the coastal sections of Southern Ca Sunday into Tuesday as PWATR moves north of 1.5 inches.

At this time…..most of the dynamics and moisture is expected to remain to the south of Mammoth Lakes. However, high elevated heat source air mass modification is expected…..and as PWATs increase from South to North, no doubt there will be some rainfall by Sunday.  Monday may be wet as well if the air mass does not get over developed to early.

At the moment, Sunday afternoon and evening looks to be the best bet for Thunderstorms for the Weekend. Highs expected in the low to mid 80s this weekend and lows in the 50s.

 

The longer range show a drier SW flow by Mid week along with some cooling…..

Next update nearly next week……

Dr Howard and the Dweebs……………………..:-)

Channeled Flow Aloft will make for a Dry Breezy Day today with little change in temperature…..SE flow to increase moisture and possibly Dynamics into the Sierra late this Weekend into Early Next Week…..

This mornings analysis showed a Trof of low pressure just off the Northern Ca Coast and higher pressure aloft to the east having the effect of channeling a Dry SSW flow aloft into the Sierra. This will make for a breezy afternoon and evening in the Mammoth area as well as the Owens Valley. Temps will be little changed from yesterday with highs a couple of degrees cooler in Bishop and upper 70s in Mammoth Lakes.

Over the next 48 hours….retrogression takes place in the Trof off the Northern Coast and the upper continental High over the east stretches westward eventually setting up over North Central NV by the weekend. With heights in the Mammoth area progged north of 994DM, Temps will again get into the mid 80s Friday into Saturday.

There is deep Moisture over parts of the Four Corners States from Monsoonal Flow out of Old Mex and Gulf of Mex. However, the upper flow is not conducive in advecting that moisture and/any dynamics into our area until late in the weekend. In fact, the new 12z GFS 700mb RH has the 50% RH line still over the Colorado River area AZ/CA Saturday Am at 12Z. However by Sunday the moisture and dynamics begin to Shift northwestward quickly Sunday into Monday.  With heat already established over the Sierra for the Weekend, it will be interesting to see if any dynamic forcing will be included in the Mix to highlight some wetting rains. Otherwise well just get a lot of Clouds and cooler temps.

 

The Dweeber………….:-)