Storm System Winds Down Over CA…..Drops between 1 and 2 feet over upper elevations…..The Next Storm Tuesday, Although Weaker…May Bring More Snowfall Than todays
Friday December 12, 2014
Posted at 1:53 pm by Howard
Saturday AM UPDATE
QPF in the Models were drier over night. Possibly because the 2nd impulse is coming in with more of a split flow. CRFC paints about .9 for Yosemite and shows within QPF, the second impulse with much less contribution for the two storms. So the 1st system has the best SW flow and orographics. There is still plenty of time to finalize the QPF forecast, however the Dweebs are expecting from this point in time, between 12 to 18 inches over the upper elevations. This is less then yesterday, but the models have changed a bit. The issue this AM is that while the 1st impulse comes through the Sierra with decent orographics….the 2nd does not .
Update Sunday AM.
Getting through the Hype:
1. The Storm today had no Pineapple Connection like the media purported! Just a lot of Subtropical moisture entrained in the initial system.
2. This was a moderate storm at best for the Central Sierra….
In my previous discussion I said…snowfall amounts 1 to 2 feet, no problem (Verified); 2 to 3 feet possibly….3 to 4 feet unlikely.
Why then was the QPF going bonkers for this past storm? Why did we not get all that the QPF indicted.
If you looked at the upper level winds, dynamics and the upper jet, it told the story of the nature of the storm. The nature of the pattern in general is a pattern where the energy in the westerlies upon approaching the coast diverts to the SSE (digs down the coast) thus diverting the UVM (Upward Vertical Motion) to the SW of the Crest. It’s like putting the peddle to the metal in a car, going down hill, then as the car reaches the bottom of the hill the motor is turned off, and the car stalls out as it moves higher. This all the while as the following cars in back speed south.
This is the pattern. The winds are more southerly with traverse Mt Ranges being favored. Mammoth Mtn virtually had no dynamics or orographics with this system.
Looking across the CONUS….there is a ridge over the intermountain west and another trof over the East. That will change with the next system….
What the Dweebs see is that the wave length will relax somewhat as the east coast storm moves ENE. that will cause more of a weakness in the western ridge.
Thus the “QPF” for the Tuesday is now more “believable”, which is more in the 2 to 3 inches range or a couple of feet for Mammoth MT. I will fine tune this later, but even though this is a weaker storm and has a weaker upper level jet, I think that the next storm for Tuesday/Wednesday from the perspective of this timeframe will bring more snowfall then the one that is wrapping up today Friday.
Because of the Screaming message that we get DYNAMICS! At this time…..the models push the short wave through the Sierra, and the upper flow is more natural to the sierra. IE its more Southwesterly! Why? Becasue the wavelength down stream opens up because of the east coast storm moving out!!
Dr Howard and the Dweebs………………………….:-)