Platinum Powder Alert Canceled for the Morning……Light accumulations are still expected over night……Cold Showery Weather On and Off for a week….
Tuesday February 19, 2013
Posted at 8:03 pm by Howard
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.
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……………………:-)
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………………………:-(