Tuesday PM Update:

Updated CRFC QPF showing a drier scenario for Mammoth Wednesday…so 1 to 4 inches is probably going to be it from top to bottom….. An inch or 2 in town as well……

Let hope for a little more westerly trajectory for the Sunday system…..

 

The Dweeber…..

 

 

The Central Sierra will continue with its cold showery pattern through the rest of the week as NW sliders move through California with little moisture. Precipitation is mostly dynamically driven. The next storm for Wednesday is showing up this morning as dryer then the last.  The Dweeb Reports lst discussion indicated that it would be a coastal slider last week. Now subsequent models runs are taking this splitting system pretty much over the top of the Central Sierra with little “over-water” trajectory of a 110knot upper jet. So expect light amounts again aprox (3 to 6 in) possible on Mammoth Mtn mainly Wednesday. Short wave ridging builds in Thursday for some sunshine! But it will continue Breezy over the lip of the sierra, (up-slope wind) especially Thursday morning with good 300mb/700mb coupling. Winds will we much lighter Friday with a milder day as well.

Weekend Outlook:

The weekend looks unsettled as another short wave….this time an inside slider brings wind, cooling and snow showers Saturday afternoon into Washingtons birthday. Again, at this time it appears to be an inside slider according to the EC and GFS…so light amounts of snowfall expected. ( a few inches). Will update Friday

Longer Range:

The Dweebs can not ignore the fact that the long range pattern in the means is showing discontinuous retrogression. This means that over the next three weeks the eastern pacific ridge will be workings its way west…west of Hawaii. This may eventually result in a very stormy pattern for the Eastern Sierra with heavy snowfall the beginning of March.  The Air Sea coupled model has been touting this for a week now with the 500mb positive height anomaly well west near Hawaii and the negative 500 heights anomaly over Ca.

The MJO which has just moved into Phase space 1 from 8 is about as far east as it is going to get, just east of the dateline. According to NCEP, the MJO is expected to remain active the next few weeks as it reemerges into the Indian Ocean in Phase spaces 2/3.

As the MJO gets into the Indian Ocean and progresses east, the PNA index will flip from its current positive phase to one of Negative. During the MJO progression toward the Maritime Continent, the upper Upper Jet across the pacific should contract, leading up to the -(PNA).

Thus the the current storms that are splitting south with small shots of energy coming into California should come in stronger from the west, as the negative phase usually rules between 70E and 100E. Coinsidently, the global models do show retrogression the end of this month, “possibly” leading up to a wet March.

 

PS: Here is the loading pattern for the +(PNA); Just flip it for the negitive phase.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/pna_loading.html

 

The Dweeber…………………………:-)

 

 


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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.