11:45pm Sunday

Quick look at the 00z Mon Euro shows a slight jog of the upper low toward the coast.  It also stalls it out near the Bay Area Thursday morning into the early afternoon.  A little better…..

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Latest Guidance shows a powerful winter storm headed for the Sierra Tuesday night and should continue through Thursday.  Because of the dry cold front that will move through on Monday, bringing breezy weather and colder temperatures, The Tuesday night storm will begin as snow for the entire Mono County area. Snowfall amounts of 5 to 10 inches will be common along the highway 395 corridor with 10 to 24 inches west of Highway 395 and between 2 and 3 feet now expected over the higher elevations of the Sierra.  The QPF for this Storm for Mammoth MT is between 2 and 2.5 inches.  Because the temperatures are so cold, the snow to water ratios will be much higher than normal, with some areas like Mammoth Mt receiving between 2 and 3 feet by Thursday night. The bulk of the snowfall will occur Tuesday night through Wednesday night.  The Town and Village at Mammoth is likely to receive between 10 and 20 inches.

Here is the temperature forecast for Mammoth this week…

Monday   Tuesday   Wednesday   Thursday    Friday     Saturday

42/14        36/19       23 /12           23/7          22/6         28

The main change in the storm for this upcoming week is that it will not linger off shore as long. There is a bit more over land track. The upper low that forms off the OR coast spins up Tuesday night and moves onshore Wednesday as heights continue to fall down the coast. In that the trofs axis remains mainly along the coast, there is plenty of over water trajectory for the storm and will hammer the Sierra well!  Again the center of the storm does not become cut off and drift south. As a result, its more progressive nature allows the storm to kick out about a day sooner.  This will limit to some extent, the long period of heavy rainfall that was forecasted for the LA basin, earlier in the week.  LA will get a good shot of rain, however, 2 to 3 inch amounts over the LA Basin are unlikely. Although, those amounts my occur for the traverse ranges.

Monday’s dry cold front dropping south through the Great Basin will dump a lot of cold air upon the Owens Valley Floor.  This sets the stage for snow not rain, for the following pacific storm Tuesday night and Wednesday.

For the Owens Valley, the more inland trajectory of the 2nd system will possibly take “some” of the punch out of the precip forecasted Tuesday night through Thursday night. There was a plume of moisture that was lurking off the coast of Baja, that will now shift east rather than get pulled up into the Inyo County area. Again, this is because of the slight change in the pattern of the more inland path of the upper low. However, make no mistake about it, there is the potential for some 5 to 10 inches of snow for the Valley, which is plenty to create problems for holiday travelers.  At the Moment, there is currently a Winter Storm Watch out for the Owners Valley. The watch remains as there is some uncertainty about how much snow will fall.  Travelers should click on the following link Monday, to see if a warning is issues by the NWS.   SEE:  https://forecast.weather.gov/MapClick.php?zoneid=CAZ520

Longer Range:

  1. There may be another storm the Following Monday.
  2. Subsequent storms are expected to have more over water trajectory and be wetter.
  3. In some of the Euro runs, an AR is showing up for around the 7th of Dec.
  4. The warm water pool that everyone was worried about off the California Coast last September, moved west some 2000 miles. This actually is supporting storminess for the state, not hindering it.

Dr Howard and the Dweebs………………………..:-)