Brought to you by Howard Sheckter
Mammoth Weather Outlook
Changes are beginning to occur in the long wave pattern now with first of several North-South Slider’s over CA and Great Basin beginning Monday…..This is a colder pattern with Light Precipitation Possibilities in our future…
Thursday February 8, 2018
Friday 11:00AM:
No surprise’s this morning… Models are consistent with dry cold front Saturday highlighted by wind and cooling. The following “Inside slider’ will dig back over the Sierra Monday and spin up off shore. Snow showers with light accumulations are expected Monday into Tuesday with 2 to as much as 6 inches possible over the crest.
Prind. point here is that the Eastern Pacific Ridge is retrograding by some 1000 miles to the west. This adjustment may continue slightly over the next few weeks or may adjust a bit back. Last nights EURO’s 5 days means are projecting a bit more westward movement, enough to drop a closed low down the coast sometime during the 3rd week of February. It’s ensemble’s retrograde the ridge to 150west or another 10 degrees west of where it will be by Sunday. The Ensemble Control is even more encouraging in that its 5 day means retrogrades the upper ridge to about 155 west by the period between the 18th and the 23rd. That is far enough west to set up a partial latitude trof off the central west coast for over water trajectory.
Now before you get too excited, this is the Ensemble Control and not the ensemble itself. I guess you could gather from all this that “Things are moving in the right direction!” 😉
Dr Howard and the Dweebs……………………..:-)
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If you were in Mammoth today driving around town this afternoon and your car thermometer read 60 or 61 degrees, that was no error. It looks like we have one more day of that before our ridge begins to retrograde westward and chilly air moves south over the far west instead of all of it spilling east of the divide.
Although I still do not see as of yet as storm track from the West, there are some changes now occurring in the long wave pattern that are encouraging at the least. Looking at several global models the past few days there is a trend now of retrogression in the long wave ridge that has been mostly east of 130 W for most of the winter to shift westward to 140W. This is always a location that will allow systems bringing chilly air from BC, Canada to drop south via the Pacific NW into either California or the Great Basin, depending upon the amplitude of the up-stream ridge.
In looking at the guidance yesterday from the European models Day+11, The Eastern Pacific Ridge is located along 140W. So expect a series of short waves to come south the next 10 days beginning this Saturday, bringing shots of Cooling and wind over the crest, and even the chance of some light snowfall. Another twist in the nature of this pattern is that these little short waves of energy can back up over the Sierra to the west coast, and spin up over water. Depending upon the location of the spin up, there is always the possibility for one of them to draw in some subtropical moisture and then give us a very nice surprise! I like surprises like the one that “may occur” early next week from a Cut Off low that may develop just west of between Paso Robles and Monterrey Bay. The Dweebs will keep a wary eye on that little bugger. Should it develop further south, it would mainly favor the Owens Valley and Southern Sierra, south to parts of Southern CA. These cut offs can be both unpredictable and unstable at times. They can produce some moderate to even strong convective thunderstorms on the west side of the Sierra and especially coastal communities with a lesser chance of some of them making it through into the Sierra. At this time, the models do not want to move this system once over water, back inland anytime soon. So well wait and see….