Archive for February, 2013

Warmer Temps the next few days then increasing clouds Saturday Night with a chance of Rain and Snowshowers Sunday…….

Dweeb Update: Star date 2.27.13@9:20pmPST….

 

Nice quite evening…..all calm on the western front…Temps in the upper 20s….

Latest operational 00z Thursday GFS has a rather unimpressive off shore ridge out about 130west that will progress into the west coast Friday. As it does…it stands up over the state. IE Amplification upstream will be the pump. As a result…high temps will become above normal with temps on Saturday 55 to 60 degrees in Mammoth.  Bishop in the low 70s.

By Sunday….the ridge shifts east to the Rockies as a rather unimpressive short wave dampens and splits during its transit through the golden state. At Wednesday AM, the Dweebs were not impressed or I should say “as impressed” as it looked Tuesday morning.  However, I will look again Friday.  In the meantime all eyes are focused upon the system for mid-week, next week. The set up with a large upper long wave ridge progressing east and a short wave coming west from the mid lats looks promising. The system gets a shot of BC, Can air prior to its arrival….as well as remnants of a small ribbon of Subtropical moisture from 140West. The QPF last time I checked the EC was running about an inch/foot of fresh.  By the following weekend (10th)….retrogression in the over all pattern across the pacific looks somewhat promising for later the 2nd week of March if the retrogression of the long wave high continues.

Again……The mid week system will be coming west underneath a developing block over AK,  this system should be good for at least a foot of fresh Wednesday over the upper elevations. Will fine tune over the weekend.  In the meantime it’s status quot except for some unsettled weather Sunday. IE Wind, cooling and snow showers…light accumulation if any….

Long Range:

It does look light some major hemispheric changes are going to take place later in the month of March.

The 06z Run last night of the GFS has quite a Kona Complex developing about the 15th in fantasyland, confluent with a significant polar jet at 140W. If this atmospheric river develops, it would be very significant for hydrological reasons for a lot of California. (This is not a forecast yet…just a model curiosity).

 

The Dweeber…………………..:-)

 

 

 

 

 

Another Dry Week Ahead……March to Roll in Like a Lamb…The Dweebs Prefer the Lion…..

A gradual Warming trend is expected this week. Last week…..The MJO rolled through the Indian Ocean, retrogression occurred across the CONUS and the long wave trof was over the Great Basin and Rockies. It got cold….we received some light snowfall and that as it! Obviously there is more to forecasting longer range than the just the track and amplitude of MJO. Other teleconnections NAO…the AO, ENSO, the PDO, EPO to name a few as well as AAM must play a part in the overall mix.

Of note, this February will go down as one for the driest for the Eastern Sierra for many years… On the bright side, Mammoth Pass is fairly close to normal precipitation for the date.

This evening there is not much to get excited about. As the MJO tracks toward and through the Western Pacific, it weakens at the same time. The PNA index  becomes quite positive and ridging over the Eastern Pacific will strengthen bringing a return of warmer weather to all of California.  The PNA index forecasted to be positive, up to 1.5 Standard Deviations of normal during the first week of March.  The Dweebs are not excited about any storminess in our future at this time. There are some indications that short wave energy will come through the long wave ridge toward the end of the 1st week of March. However, it is way too soon to speculate on if we will get some snow. In that March is right around the corner…..cut off low season is as well.

In the meantime, next weekend from a fair weather point of view looks about as nice as it can be for the first few day of March. The Lamb has the upper hand, while the lion has apparently lost his way….ok….have a nice day….. 🙂

 

The Dweeber………………..:-)

Platinum Powder Alert Canceled for the Morning……Light accumulations are still expected over night……Cold Showery Weather On and Off for a week….

Wednesday PM:

 

The Dweebs are not liking today’s 6 to 10 day and 8  to 14 day 500mb height maps for late Feb and early March……

Strong +PNA and -NAO are highlighted….

 

Wednesday AM update:

The upper low over Southern Ca will slowly shift east into AZ today. Up-slope snow showers are falling along the eastern slopes of the Mono County Sierra and should gradually diminish this morning.  There is one sizable band of showers over the Lucerne Valley on the back side of the San Bernardino Mts at the moment. The upper low at 500MB as well as at 700mb is currently shifting into AZ.  Gusty north winds will take over the Owens Valley in its wake.

Apparently, the foothills of the western Sierra….Kern Co Mts, grapevine and the Central and San Joaquin valley got hit the hardest. There was even a tornado reported yesterday north toward Redding, Ca.   The east side of the sierra received light amounts with general amounts of 6 to 8 inches between 9K and 10K.  The weather will remain unsettled through early next week with scattered snow showers on and off in a NNW flow aloft at 500mb. . There is a stronger NW slider coming in Saturday that may dig a bit further south through the Great Basin….Possibly good for an inch or two of powder.

OUTLOOK:

A cold Long Wave trof will continue over the inter mountain west with the upper jet coming in from a NW or a Northerly trajectory. This is a pattern that will keep the Sierra both colder than normal and dryer than normal. There will be several short waves in the upper flow. Baring a short wave that shears and splits off to our west….The trajectory suggests that any precipitation would most likely continue to be light. This pattern is expected to continue through the end of the month….

As we go into March….Further retrogression of the eastern pacific high may allow a period of westerly flow to develop….The upper jet would then have an easier time to pump more moisture in the Trop.  So a milder pattern with better chances of normal precipitation is more likely.  Thus there is an elevated chance of a wetter storm later during or just after the first week of the new month.

 

Dr Howard and the Dweebs……………………:-)

 

 

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Apparently…the models were wrong in the placement of the upper low as it is verifying too far west. As a result, the focus and bulk of the precip is over the San Joaquin Valley. Heavy down pours and thunder are currently rumbling south of Mammoth in the foothills of the Sierra…east of Hanford and Fresno.  Sierra Crest updated amounts are now in the 3 to 6 inch range for the upper elevations and possibly just enough for a plow in town.

 

Of interest this evening is an area of showers near Fallen, Nv in the deformation zone. It is possible that once the upper low center gets down around Paso Robles, Ca, the upper flow will circle around from the NE and bring us some upslope late tonight or in the AM.

Lots of hopes tonight being lowered as mother nature just not ready for a good Ol’ fashion snow storm quite yet…

 

The Dweebs criteria for a Platinum Powder alert for Mammoth Mt is at least 1 foot of powder at ratios equal to or greater than 15:1.

It is doubtful but not impossible that we will get that by morning……

 

Update in the morning………………………:-(