Possible BIG storm 20-23 March

[donbrown]

Computer models think 2 inches of heavy rain at 7000 feet and should be sierra cement measured in feet.

Be aware it is common for a march storm to "dump" into the ocean prior to coming to shore/land.



www.mammothweather.com

Wednesday March 13, 2013


Posted at 3:12 pm by Howard
.

All the Dweebs can say is Wow! Our weather is way too nice for this time of the year…..



The strong upper high over California will weaken this weekend to allow considerable high clouds into our area beginning later Thursday. Temps will remain in the low 60s until Friday when a slow cooling trend develops. The cooling is more due to falling heights and cloudiness then any cool air advection.

The next important change comes to the Eastern Sierra when the wave length opens up a bit across the Conus. Notably, Week 2 when positive height anomalies pull far enough north next week and allow more energy to break under the Greenland Block. This looks promising. I think…I mean I hope that the ECMWF has the right idea now as the latest GFS and GFSX has been coming over to its idea of a storm about mid week, next week.


The ECMWF is pretty wet. It appears to be taping into a mid pacific westerly flow (Subtropical jet) and is generously painting 2+ inches (QPF) for the Central Sierra next week between Wednesday and Friday night.

The GFS is looking promising as well. However….I would approach this with caution as drought patterns like the one we have been in the past 8 to 10 weeks do not change that quickly. Rather…they tend to fade away with the seasonal change.



So try to enjoy the beautiful weather. I realize that it is difficult. I Will update this Saturday Night or Sunday the latest…..



The Dweeber…………………..

 

[donbrown]

Computer models disagree.

One says 1-2 feet the other says flurries.

Went from many feet to 12 to 18"



More Snow Expected Next Week……However Less Than Earlier Expected…….More Updates Next Week…….


Friday March 15, 2013


Posted at 5:50 pm by Howard
.

Brief Update:

Next weather system will be still running into the head winds of the mean ridge position. The wavelength resulting form the ongoing Greenland block will cause quite a bit of splitting. The system looses a lot of its punch and the models both the GFS and the EC are less in agreement now. Usually when you get closer to an event the models come together. In that they are deviating….Not a good sign. Nevertheless, we will get enough snow to freshen up the base. If you biting down on the EC… the European has backed off a bit now on the QPF. Although it is still painting about 1.25 over the Mammoth portion of the Sierra next week. The GFS has much less. Still have time to watch it though. The Dweebs will update again Monday.

For those that wonder why I have not updated as frequently in the past three weeks. My computer was hit with a nasty virus. I hope to be back up only more frequently next week. If I find out who it was…I will give their address out so you may have your way with them.

Some Rumor’s about a big storm at the end of the Month. Just RUMORS……..>>>>> Will take a good long look ahead next week……>>>>



The Dweeber………………………………..

 

[donbrown]

Snow levels will be high above 7000 BUT levels may fall is isolated temp inversion areas. Good snow above 9000 feet. 6 to 18 inches.


www.mammothweather.com

More Snow Expected Next Week……However Less Than Earlier Expected…….More Updates Next Week…….


Posted at 5:50 pm by Howard
.



Sunday PM Update:

Models have come in a little wetter this afternoon with the EC generating up to an inch over the crest. I think that is good for the crest. This is for the period Tuesday through Thursday AM 19-21March . The GFS is a bit dryer. However, it too is a bit wetter then last nights run. The subtropical system has already occluded and is cut off about 1000mi west of the central coast wine country. The system will combine off shore with a system coming out of the Gulf of AK…..but seems to dampen before moving inland producing a weakening front. Thus the lift will be mostly from orographics which will be decent and because of PWs of up to 3/4 of an inch the potential for 10 inches over the crest seem like a good bet now. SWE Ratios will be low….6 or 7:1 at the main lodge and 8 or 9:1 over the crest. There will be a lot of shadowing east of the crest so like the last system snowfall amounts will be unimpressive in town.

CNRFC has freezing levels over Yosemite Tuesday night over 9800 ft, and through Wednesday around 9500. If the atmosphere is saturated and isothermal, snow levels could fall into town. This is a big if through. Otherwise this will be a rain/snow event for the town…. Best guess an inch or two of slush at 7000 feet in Mammoth.

Another update Monday…………………………………….>>>>>



Saturday Night Update:

Latest modeling is splitting the Wednesday system pretty badly. This is not going well as only light amounts now expected….

Will update Sunday….

 

[donbrown]

Best snow conditions in midwest in over 100 years.

Computer models show HUGE storms every couple weeks ... typical for this time of year

Also typical shows storms coming in like a lion with impacts like a mouse.


www.mammothweather.com

Current Storm System Off Shore Has Plenty of Fuel….However Not Much Spark! Nevertheless Mammoth Mt will get a nice Freshing of its Surface Mid week…..The Following Weekend Will be Fair…


Monday March 18, 2013


Posted at 9:37 am by Howard
.

What do you get with a juiced up atmosphere with no spark? A waisted opportunity that is for sure….

The Spark being referred to is dynamics. Dynamics creates lift. It takes lift in the atmosphere to squeeze the sponge. Where is the lift? Looking NW it is in the Gulf of AK. But the timing is off. The Moisture will get in here Tuesday and Tuesday night before the colder system with its lift does on Wednesday. The basic lift involved will be orographics. I do not expect more then a trace to an inch or two in town Wednesday. Snow level will be 7500 ft Wednesday.

Amounts will range from 6 inches to 10 inches on Mammoth Mt. (9500ft) Snow to Water Ratio’s ave 7:1 QPF from mainly orographics, .5 to 1.0 (heavy snow)
Of course this is not the whole story. There are more fundamental issues that are still causing the head winds, “figuratively speaking” and the persistence of the dry pattern we have been dealing with since the beginning of year. In short, the (-AO and -NAO Combo) have done a job on us this winter, and we are/will continue to feel its effects in a negative way until that system breaks down! Look at the standard deviations of normal in the -AO…almost off the charts!!!!!!! It is no wonder why the mid west and the east have had one of the snowiest winters in the last 100 years….
-AO: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

-NAO: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

Until the -NAO returns to at least neutral, its drought city for the central and southern west coast. Now this pattern was some what predictable by knowing that the QBO was heading toward neutral during the coldest part of the year. Remember that when the QBO index is in transition, -10 to +10 it points to a greater degree of certainty of the formation of the -AO/-NAO Combo) during Jan, Feb, March. Calculated at PSD (from the zonal average of the 30mb zonal wind at the equator), as computed from the NCEP/NCAR Reanalysis). SEE: http://www.esrl.noaa.gov/psd/data/correlation/qbo.data

Long Range:

From What the Dweebs see….That system will stay intact through the end of March and will slowly break down in April which may lead to a wet April into early May.

See CFS v2 500 hPa z For weeks 1 and 2 http://www.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk1.wk2_20130317.z500.gif

Weeks 3 and 4 http://www.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/images1/wk3.wk4_20130317.z500.gif

As you can see, the Block really breaks down in April….





Dr Howard and the Dweebs………………………………………..


Definition for the day ...

Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions, precipitation. A common example is seeing a "cloud" form downwind of a mountain ridge or peak.