Archive for February, 2014

High level Cloudiness Will Continue to Spill Over the Upper Ridge into Eastern CA…….It will be warmer today and about the same Friday….Upper Jet Sags South Saturday with High Winds expected Saturday PM

A beautiful day is expected throughout Eastern Ca with warmer temps and breezy conditions over the higher elevations. Highs in Mammoth will be in the mid to upper 50s the next two days with high clouds and strong breezy conditions over the upper elevations at times. There continues to be an impressive upper subtropical jet coming out of the Central Pac into the Pacific NW. This jet will sag south with time into the Central Sierra Saturday/night with a potential High Wind Event, Saturday PM for Mono County.

The hose that is currently pointed at the Pacific NE will slowly shift south and weaken to a trickle by the time it reaches the Mammoth area. Nevertheless…we may end up with a few inches of snowfall Saturday Night and Sunday AM. A bit more could occur over the crest as usual with orographic’s. At this time I do not expect any more then 3 to 6 over the crest by noon Sunday.

The Dweebs are all over the storm expected the middle of next week. Looking at the GFS guidance, there is still a tropical connection, however its continuity to the west coast will get blocked later next week as mid latitude short wave ridging sets up in-between Hawaii and the northwest. So the hose has a block put in front of it and the water gets squirted directly into the westerly’s behind the upstream ridge.  This may have the effect of prolonging the precip event in the northwest flow following the main short wave a week away. that is if the short wave ridge is not too amped. Although it is too far off to get excited about major amounts,  I would not be surprised to see a foot or two the second half of next week, or more if the storms lingers over the far west like some of the longer range models are hinting at. So to be clear, this is a tap of Subtropical moisture Tuesday into Wednesday, but thereafter it gets cut off by the Cold front later Wednesday PM.

There has been a change in the depth of the long wave trof over the far eastern pacific the past few days as the pattern in general is more dampened with less amplification. It will be interesting to see if that trend continues, or if it reverts back to being more amplified with a deeper long wave trof over the far Eastern Pac. It will not take much of that to happen height wise, to effect Mammoth. Unfortunately for the Southern CA area, this does not appear to be a major storm for you folks.  More later…..

 

Dr Howard and the Dweebs………………:-)

Atmospheric River has shifted into the Pacific North West while Central and Southern CA are under a Subtropical Ridge…..Expect Warmer, then cloudy weather the next four days and Windy Weather Wednesday and Thursday……Unsetteled Weather is expected Saturday Night into Sunday AM…..Next Major Storm expected by middle of next week….

While the Pacific NW gets the Hose……The Southern Half of the West Coast gets Clouds, wind and Sun.  The latest guidance shows a subtropical ridge building into California thorough Midweek and holding through Friday. The strong warm air advection pattern to our north will begin to sag south this weekend effecting Mammoth by Late Saturday night. Freezing levels will begin high, about 10,000 feet late Saturday night, then come down late Sunday Morning to 6500. The QPF is about .65 for the Mammoth Crest. So once again, it will be snow over the higher elevations above 8500-9000K from about midnight Saturday night then some very light accumulations possible in town Sunday Mid Morning. The snow level is expected to lowers to 6500 by 10:00AM Sunday at the end of system. Early estimates of 3 to 6 inches are possible up on Mammoth Mtn by Noon Sunday and about an inch or two in town at 8K.

Between now and then we’ll have warmer days and cloudier days as well.  It looks especially windy Wednesday through Thursday with the Front Rt Exit region to the north, forcing NW Flow with 30 to 35 Knots at 700mb, which I double for Mammoth Mountain over the crest for forecasting purposes. High temps in Mammoth will be in the 40s one more day today, then into the 50s Wednesday into Friday.  Again….Warm air advection precipitation will begin to make its way into the Mammoth Crest late Saturday night and be pretty much be over by 12:00 noon Sunday.

Longer Range:

The period Monday night through Thursday of next week looks stormy. I like the fact that all the popular global models including the GFS, GEM and ECMWF are singing the same tune. While there are timing differences, and the GEM is not nearly as deep with the Trof coming in, as compared to the EC and the GFS. It still all looks good for a winter storm. I primarily used the ensembles of all three models this far out in time as their deterministic runs would not be as accurate. I did note that the timing is earlier with the latest deterministic Tuesday 12Z GFS run. I think that that makes sense, as the corresponding western pacific surface cyclogenesis bombs out early, and crosses 140E early as well. So do not be surprised if the zone forecasts introduce snow as early as Monday night next week for Mammoth.

All in all this looks like the potential to be a major storm in the high country with much lower snow levels and a good couple of feet of snow. And the town too should participate with moderate amounts of snowfall.

Interseasonal:

I had a peak at the CFS (Climate Forecast System) for the next 45 days. It looks pretty promising for some 6 to 7 feet of snow, now through the end of March. That is based upon its QPF of 6 to 7 inches at 10:1 ratio. Correction…..Aprox 5 to 6 feet at 10:1.

 

 

 

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

 

2 to 3 Feet of Fresh Snow Fell over the Weekend on Mammoth Mt….Expect improving weather this week with clouds….winds mid-week then a return of Unsettleld Weather by Sunday…..

As the weekend storm exits our area, drier, warmer weather is expected as a strong mid latitude ridge builds back into California through Friday morning. The upper ridge looks fairly dirty, so cloudiness associated with a storm track to the north of us, will come and go with time. Heights will be fairly high and so above normal temperatures can be expected most of this week.  Highs in Mammoth will be in the 40s through Tuesday then 50s Wednesday through Friday.  Night time lows will be in the teens and twenties……It will be windy Wednesday.

West Coast Storms:

Although the South Central Sierra will have a break from precipitation this week, it will be quit stormy in the pacific NW.  Another “AR” event is set to connect with the states of Oregon and Washington so it will be very wet up there. The source region of the tropical moisture reaches back to the Dateline and the ITCZ, so it will rain a lot up to our north. Although we will not get rain from that system, we will get a lot of high cloudiness along with wind….especially Wednesday. The major long wave that is involved in training the pacific NW moisture will shift east over the weekend and dampen as it runs into the west coast ridge. As the remains comes through California, the Central Sierra may get some scattered light precipitation along with wind and cooling Sunday.

Longer range:

I am beginning to see some signs that the winter pattern of the northerly displaced upper jet is beginning to break down. There appears to be more long wave Trofing in the medium to long-range in the Central G of AK and less high latitude ridging over or near the west coast. A couple of weeks more will tell more, but often times dry winter patterns begin to break down in late February and into March. This mornings day +8 GFS showed a long wave trof  between 145W and 150W. SEE: http://www.hpc.ncep.noaa.gov/cpc/cpc_NHEM_f192wbg.gif  This is still too far west as I would like to see it at 130 west but things are moving in the right direction. Additionally, I am seeing a weaker PV over Eastern Canada and much more progressive flow out over the Atlantic. So the wave length appears to be becoming more favorable for a progressive shift in the long wave trof from over the Central Pacific to the Eastern G of AK with time.  Additionally, the west coast ridge is forecasted to move over the Rockies where it belongs the next week.

Thus……A significant storm is expected about the middle of next week that could be a major cold type winter storm for the central west coast. I checked for verification using the Hovmoller theory for surface cyclo-genesis coming off Japan next weekend and it supports the propagation of energy through the west coast about Wednesday next week.

 

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