Archive for July, 2015

Remnant’s of Dolores’ is over the Sierra Today…..Very light upper flow combined with high instability indices will increase the possibility for heavy down pours in many areas today for Mono County….Main action will shift off to areas east of Highway 395 by Wednesday afternoon as an Upper Trof with Drier Air approaches…..This up coming weekend will be Fair…Dry and Warm………

Today Tuesday appears to be potentially the most active day for thunderstorm’s with heavy downpours. This mornings sounding showed a weaker inversion above 16,000 feet than what was the case yesterday. This means that there is a weaker warm air pocket in that area causing the Cap to the lift yesterday. Additionally…..increased moisture from the remains of Dolores’ and a CAPE of close to 1,000 J/KG and lifted’s  -3 to -5  will be more than enough over the higher elevated heat source of the Sierra to punch through that weak inversion.

The NWS-RNO has issued a flash flood watch for Mono County from 12:00pm Tuesday to 8:00pm Tuesday night, for the potential for heavy rain downpours in showers, and flash flooding in areas that are susceptible.  If you are traveling over local mountain passes be careful of falling rocks on to highways and if fishing in areas of Creeks and Streams during heavy rain storms today, move to high ground.  Highs today will be near 70, lows near 50.

Outlook:

As an upper trof with drier air begins to approach later Wednesday, thunderstorms will form over the sierra in the morning and push-off to areas east of highway 395 during the afternoon. So there is the threat of more rain Wednesday but it will be mostly east of the sierra crest by afternoon. High temps will be a little warmer Wednesday afternoon. Afternoon and evening SW winds will increase.

By Thursday, the threat of rain should be all confined to areas east of highway 395. The upper trof pushing in will continue the southwest winds over the upper elevations and continue the drying process. Breezy weather is likely Thursday with warmer temps Friday. Highs will climb back into the low 70s, with over night lows in the upper 30s and 40s.

This weekend’s outlook will be fair, dry and warm with highs in the mid 70s at resort levels and nighttime lows in the 40s. Expect the usual light diurnal afternoon zephyr winds…

 

Longer Range……Always subject to change…….:-)

OK…. where are we headed the next week in this unusual El Nino Summer!

As we wrap up the weekend….The beginning of the last week of July looks pretty uneventful.  Somewhat season temps can be expected with fair skies. So High temps will probably remain in the low to mid 70s with lows in the 40s, pretty much like the weekend. With that said, the second half of the week will be different. Looking at both the Ensembles of the GFS….and Ecmwf from last night, The GFS shows a somewhat progressive pattern with initially the Continental High over the SW expanding westward with a warm up Wednesday into Friday then it progressing east over that weekend.

The net result would be a stronger zephyr over the Bluesa weekend with daytime highs in the upper 70s.   However the ECMWF has a different scenario. It retrogrades the desert upper high over CA and brings on a heat wave with highs in the 80s for Mammoth. Not too shabby for the beer drinkers Saturday afternoon. The nights would be warmer too with low 70s continuing possibly until nearly 8:00PM with very light of any winds. Thunderstorm action would not be likely.

At the moment, I do not have a bias either way. I do not see a reason why the EC is retrograding the mid level pattern. One interesting feature is that the MJO has moved in over the Indian Ocean. That can cause some retrogression, however the dynamic models are not picking up on that. Only for some reason, they show an incursion into phase space 1-2 which is not connected to the MJO. Some of the dynamic models are possibly picking up on a lower frequency signal like an atmospheric Kelvin Wave.  Will update tomorrow AM after the CPC briefing today on this curiosity.

 

Either way the weather looks great at this point in time for the Mammoth Festival of Beers and Bluesapalooza, with either seasonally warm temps in the upper 70s with afternoon breezes or it will be well above normal in temps with highs in the mid 80s with out much of any breeze.

 

Tuesday 12:00 UPDATE:

 

Just had a look at the new high Res deterministic GFS 12Z Tuesday Run. It looks like the ECMWF Ensembles….so its leaning toward the hotter end of the month scenario.  The big question will be is there is going to be SE flow up the CA/NV Spine?   Too soon to tell….

5:10 PM Tuesday Update:  

OK…here we go again!    dé·jà vu to last June.   The deterministic runs and ensembles are trending to a similar pattern in June with 597 MB heights over Nevada with SE flow following. This is where we got the hottest temps of the Summer in mid to late June followed by a Thunderstorm break out prior to the Fourth of July. The Dweebs just hope the rains hold off until after the Bluesapalooza.

 

 

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

Monsoon Moisture Along with some dynamics to bring an increase in Thunderstorms Sunday into Monday…..Otherwise Fair and dry through Saturday with Seasonal temps….

Sunday AM:

 

Will make this as quick and clear as possible this AM:

At the moment,  up at 300MB there is a weak WSW/ENE upper trof or boundary that gets pinched off into an upper low off the central coast this afternoon. This boundary has acted as a barrier in the northward movement of moisture. You might have noticed some wind in the afternoon from the west. This has been part of it.

This E/W trof will disappear today. The 12Z NGM creates a lot of CAPE over Mono County and the fact that we are becoming on the NE quad of the upper low off shore will add to the coupling by creating Upper Divergence.

Expect Thunderstorms to develop this afternoon and into this evening mainly south of Bridgeport.  The Remains of Dolores will come in adding to the dynamics with additional moisture Monday into Tuesday. If there is plenty of sunshine both days. Heavy wet thunderstorms are possible with flash floor potential…not only during the daytime hours but Monday night and Tuesday as well.   Dry weather will return Wednesday into Thursday with an unseasonably cool and breezy trof……

 

 

More later……………………………

 

 

Thursday Night: A quick look to compare the 00z GFS QPF with the 00z ECMWF shows the GFS a lot drier. However, the ECMWF is quite wet with the Combination of Dolores and some dynamics near the area.  So at this point, it could go either way as far as heavy rainfall.  Odds are good we’ll get some rain. Question is will we get a lot of rain….The IOP is Sunday into Monday. ENSO: A combination of an Atmospheric Kelvin wave that translated east, strong westerly wind bursts late June and early July along with twin cyclones on each side of the equators near 160E, did its magic 3+ weeks ago.  This is all being reflective in the further recharge of the Nino Basin and the boost in the CFSv2 indices’.  El Nino looks Super! …….  😉   Update Friday afternoon: ————————————————————————————————————————————————————————————————————————————————————— Last nights GFS Models continue to down play any significant effects from weakening Hurricane Dolores this weekend. Although some remnants are certainly picked up by a weak mid latitude circulation off the central coast of CA, the stronger upper jet over CA that was earlier forecasted by the models for this weekend does not appear in the picture anymore. Looking at the 06 Z GFS from late last night, both the 300MB and 250MB upper winds and jet structure is further east now favoring Arizona and New Mexico. So it is in those areas where you will find the best “Upper Divergence” for precipitation this weekend. Additionally, I did not see any impressive CAPE over the Eastern Sierra in the model as well. So the odds as of this point in time, for major thunderstorm action is greatly reduced. Just possibly some widely scattered action is currently expected Sunday into Monday.  With that all said, there will be a big push of Monsoon Moisture from Mexico as well as remnant moisture from Dolores. This may end up a being classic example of lots of moisture but no wide-spread convection because of the lack of significant upper divergence necessary to create a significant thunderstorm pattern over the weekend.  The Dweebs will be watching for any sign of a wave or vort max from the SSE flow later this weekend to generate dynamic  lift. Additionally, there is some suggestion that Dolores may morf into or become part of a weak mid latitude upper low early next week.  If a mid level upper low develops and its NE quad favors Mono County, that would be a localized situation that would make a difference in thunderstorm coverage for Mammoth Lakes about Tuesday of next week.  The Dweebs will take another look at it Saturday AM or sooner if necessary.   Longer Range: Another potentially strong upper trof for July will descend from the G of AK about Wednesday or Thursday of next week.  This would bring a return of a dry air-across the region as well as some cooling with stronger afternoon west or SW winds. There is one more hurricane worth watching for later next week. At the moment, just like this weekend system, the models show the upper trof to the north shifting east before the window of opportunity of the next TS get close enough to CA to make a big difference. That of course is subject to change as we are out in time a long period.   ENSO/MJO The transitory convective envelope of the MJO should be out of the Tropical Eastern Pacific “during the 1st week and into the 2nd week of August. So the emphasis of tropical storm action may shift into the Gulf of Mexico if the MJO is strong enough to make a difference. At the same time, the suppressed state of the MJO will have moved into the eastern tropical pacific, with possible destructive interference with the EL Nino Base State. The result would result in less TS action for the tropical eastern pacific developing sometime during the 1st week of August.  Again, this is only if the MJO remain strong enough. All systems are go for a strong El Nino event this Fall and Winter for at least the Southern half of the State.   Dr Howard and the Dweebs……………………………:-)

Beautiful Eastern Sierra Weather on Tap for the next few days…..Moisture from Dolores in doubt again as she spins up…slows down and most likely will miss the window of opportunity of getting picked up by a weak west coast trough….

Beautiful weather will continue here in the high country with highs in the mid 70 and lows in the upper 40s……Moisture from Dolores in doubt again as she spins up, slows down and may miss the opportunity of being picked up by an approaching trough.   Will take one last look at it tomorrow AM…

 

In the meantime expect fair days with the usual afternoon clouds and isolated TSRWs over eastern portions of Mono County…   Highs in the mid 70s lows in the upper 40s…

 

 

The Dweeber…………………….:-)