Archive for year 2019

Chilly weather to give way to a milder weekend…..Then Ready-Set-Go for Snow!!

 

11-24

 

 

I will be posting this afternoon…

 

just a quick note to say that the storm looks very good.  Although it may lift out more like Friday instead of Saturday….

 

It still looks like at least 1 to 2 feet and possibly more on the mountain by the next weekend.

Prime time is Tuesday night into Wednesday.   Snow for the Owens Valley Wednesday and Thursday…..as much as 5 to 10 inches in some places.

 

Dr Howard and the Dweebs…….

 

 

 

 

 

 

 

10:00am

 

quick comparison of 12z run to 00z shows some shift of the upper low a bit inland in its track. Some height rises on back side of digging trof.  Will have to follow this change to see if it shows up in future runs….

 

________________________________________________________________________

Saturday Am

Note for holiday travel to the high country

Travelers to the high country via the Owens Valley will want to pay very close attention to the Weather and Road conditions  for Wednesday. This storm with its very cold temperatures and the fact that it will remain along the coast some what cut off is setting up a rather long period of upper difluence over the southern half of the state. This looks like a classic snow pattern for the Owens Valley.  1000-500mb thicknesses suggest a snow level of between 3000 and 4000 feet.

So temperatures will be cold enough for snow on the Owens valley floor early Wednesday into Thursday.

The storm is still a good 3+ days away and the timing still being worked out. However this type of storm suggests that travelers begin their travel with an especially early start to the high country. Tuesday would be better for travelers.

Please keep close tabs on the forecasts from the national weather service over the next 5 days and prior to departure, check road conditions from Cal trans.

The Dweeber……..

__________________________________________________________________________________________________

8:30AM 11-22-2019

Last nights Euro and GFS are consistent with previous runs, with the placement of the upper trof. Differences show up in the Run to Run height field with a lowering heights in the back of the trof. This suggests more digging and the ability for the storm to remain off shore longer.  The Euro shows “possibly” some bombing. Not sure if it meet that criteria, with the surface low west of Pt Arena going from 1003 mb to 975mb within a short period of time. Needless to say the storm has the potential to bring some strong winds to areas.   I think that at least for this period time, the EC has a better handle on the pressure field as compared to the GFS as the GFS has come into more agreement with its 06z run. The emphasis is going to be on the cold and snow for most areas of the eastern sierra by Mid Week, including  parts of the Owens Valley….  The Storm will eventually move in over LA and provide up slope to the Eastern Sierra next weekend…  In that the storm taps some moisture from North of Hawaii, the QPF still looks very good, in the 1 to 2 foot range for the upper elevations, but no doubt will be updated in the coming days…

The Sierra, north to south will do very well from this weather system…..

 

There is another weather system following by the very end of the holiday weekend that will be more of a cold inside slider….Stay tuned on that one as well

 

Stay Tuned,,,the Dweebs got you covered…..

__________________________________________________________________________________________________________________________________________________________________________________________________

8:50PM Thursday the 21st…..

I thought I would post again today…this evening.

I looked at the new GFS 00Z Friday and the Trof axis is very very close to the west coast. It stays there for several days. I am waiting to see if we get a closed low that spins up Tuesday night that heads south down the coast and wallops LA with soaking rains like the EC showed this AM.  I am awaiting the 00z Friday Euro and I will update in the morning before 9:00AM.  But now to the good news….

The new 00Z Dec 21st ECMWF weeklies, that go through December, have updated and the ensembles show more and more over water trajectory of wetter storms for the Sierra as we get on in the month of December.  This is great news.  What I really like is the 7 Day ensembles means in the weeklies during the 2nd half of December.  The Negative Height anomaly is over the far west!

_____________________________________________________________________________________________________________________________________________________________

It never ceases to amaze me how quickly the weather can turn, not only here is the eastern sierra but over the western hemisphere. This time a massive ridge of high pressure develops over the north pacific at around 150 west Tuesday. Our ridge off shore retrogrades and joins up with a large short wave ridge currently coming off Asia. The two meet next Tuesday and amplify north,  while a massive thrust of modified Arctic air pours out of Eastern AK and Western Canada. The redevelopment of the subject ridge provides a direct pathway of very cold air down the west coast. Just off shore…Rapid Cyclogenesis is possible Tuesday evening.  The system then slows and parks itself along the west coast for two days!   700MB temps are -12 to -13 Tuesday night, cold enough to brings snow to even the lowest valleys of Mono County! Amounts of snow fall at this distance in time still in question. However, considering the snow to water ratios…some 1 to 2 feet would not be out of the question for Mammoth Mt. This will be fined tuned later. The GFS has a bit more over water trajectory so it would tend to be a little wetter.

 

I would still prefer a wet storm of sierra cement for this period, but will take what we can get.   The storm looks to last for two days….  Beginning Tuesday night….

At this time, the Southern and Central Sierra look to receive the heaviest amounts. LA will get some heavy rains as well.

This may bring significant travel issues for the Sierra for early holiday travelers…because of the powdery snowfall and the likelihood of a period of blizzard conditions …..

 

Stay Tuned….

 

 

In a flash…the Warmth of Fall is Gone….New weather Types Await the Eastern Sierra……..

It was just two days ago, our highs were in the upper 60 and today upper 20s..   That’s pretty remarkable and difference in 40 degrees of cooling over two days….   Our closed low that brought us rain and snow showers to town yesterday afternoon has moved inland and located over Kern County. it will meander in the same areas today before moving over southern NV later Thursday AM. The Rapid Refresh model brings some .25 to .5 inches of QPF to our area, Mainly this evening. So expect a better chance of snowfall accumulations this evening. (2 to 5 inches)

After a chilly day Friday, expect a fair and cool weekend with high climbing to the upper 40s by Sunday.  Thereafter it will grow cooler Monday and Tuesday as a NW slider pushes drier cooler air into our area from the Pacific NW.  Night time temps will be in the 20s, then teens early next week in the drier air.  Snow making is full on now on Mammoth Mtn.

The comments from the CPC were well taken yesterday. Again they are looking at the possibility of a cold western trough late this month and into December. Exactly where it sets up will be key. This is an even colder weather pattern than what we have now.   The storm track will retrograde a bit around the Thanksgiving holiday. That means that there may be more over water trajectory and a better chance of accumulating snowfall.  However the main emphasis is going to be the cold that will be headed our way toward the end of the month.  Both the Euro and the GFS still have their differences and a difference of only 100 miles will be a big deal on how much snow we get from the changing weather system. Further retrogression of the western trough is expected in December…..

This month….These systems will still spin up off the west coast and drop south over California. That is usually not a great pattern for snowfall, but again, a little more of an off shore track would make a big difference. December looks much better!

 

I will have the EURO’s long range outlook update this Friday for snowfall in December…..

 

Dr Howard and the Dweebs………….:-)

 

 

Impressive heat wave to end today with 30 to 35 degrees of cooling expected by Wednesday…light snow in forecast for Tuesday night and Wednesday with fair dry weekend…,

 

3:45PM Tuesday the 19th

 

There was a very encouraging update for the CPC this Morning.   They chat about the extreme IOD out over the Indian Ocean. That is bringing flooding to parts of Africa and drought to parts of Australia. They now expect a response to the mid latitudes which is surprising!

This post is pretty esoteric, however, I know that there are several Dweebs out there that they will be happy to read this discussion…..

 

From the CPC today:

The MJO remained active during the past two weeks, propagating rapidly across the Pacific before returning to the Western Hemisphere. During the past several days, the RMM index stalled over the Western Hemisphere. This slowdown is likely due to constructive interference between the MJO and the strong positive phase of the Indian Ocean Dipole (IOD). Dynamical model forecasts of the RMM index are mixed, although most depict weakening with no additional propagation to the eastern Indian Ocean or Maritime Continent during the next two weeks. In addition to the IOD which favors convection over Africa and the western Indian Ocean, robust Rossby wave activity and above-normal SSTs across the central Pacific may help generate additional convection that is “out of phase” with the current MJO event. This may be why some GFS and ECMWF ensemble members favor a quick return of the index to the Pacific. Based on these forecasts, the MJO is favored to play a diminishing role in the evolution of the tropical convective pattern over the outlook period. The IOD will likely become the “dominant mode” of tropical variability, and widespread convection over the Western Indian Ocean may teleconnect to the midlatitudes and help change the downstream pattern over North America with more “troughing across the West”. 

Dweeb Comment….For one thing, it this comes about….This is likely to bring some very cold weather to the Eastern Sierra in December…..  The fact that this IOD is going to become the dominant mode of tropical variability is pretty astonishing! Get ready for the possibility of some Real Arctic Air in December…..

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

68 degrees for the 18th of November?….Pretty amazing for Mammoth Lakes. Not a real heat wave but pretty mild for November. In looking at the Bishop Airport obs…so far 77. Official records were broken over the south-land today with highs in the low to mid 90s in some areas. Our storm system will drop quickly south tomorrow and actually track somewhat inland. Moisture will be provided by remnants of Raymond as well as off shore. The best area of deformation, (Surface Convergence) seems to be over Northern Mono and Eastern Alpine counties. Areas just east of the CA border may get up to a foot of snow in some of the mountains. Here in Southern Mono, somewhere between 2 to 5 inches seems reasonable. (Light Amounts) Areas east of Mammoth may do pretty well. Crowley Lake, Toms Place and Sherwin Summit may have some surprises….

This is not your usual Fall/Winter Weather system with a cold front. It is an area of Low Pressure that develops and spins up as it drops down or just east of the west coast, combining some moisture from a cut off low off Baja along with some of its own from off shore. It is small, but packs some real cold with it.  Highs in Mammoth on Wednesday will be in the low to mid 30s…..Some 30 degrees of cooling expected.  The storm clouds will retreat Thursday night leaving a fair dry weekend. The next system looks drier next week and the following one toward the end of the month may be colder yet and showery….

The Dweebs do not see any wet systems until we get into the month of December, where according to the longer range Euro, may bring some real snow!!

PS, the colder temperatures will really enhance the snow making efforts on Mammoth Mountain. I expect the snow making crews to be able to make a lot of snow and open many more ski and boarding runs over the next week.

 

Dr Howard and the Dweebs……………….:-)