Upper ridge at 140west….and mean trof over the central Conus with the upper jet north/south in-between. That’s the dry story through mid week. Outside of strong gusty winds at times over the crest and high clouds on Sunday….not much going on.  Expect highs in the low 50s in Mammoth and lows in the 20s.  Beautiful Fall Weather!

Longer Range:

Medium Range models now beginning to look simular. (GFS-ECMWF) There are timing issues between them. The Global Forecast system has been leading the way with the big weather change and now the EC is following suit.

Both global models initially retrograde the big upper high near 140w  midweek. Both models develop a strong upper jet that taps into a vary cold air-mass, then phases it with southern stream energy with plenty of moisture.

Last nights 00z GFS had strong amplification early Tuesday morning near the dateline which taps a very cold air-mass over Alaska while southern stream energy undercuts the strong mid latitude upper ridge that is building northward. Cold arctic air is pulled south from about 80 degrees north between the strong upper high over the Aleutians and the cold upper low developing in the Gulf of AK near 140W.

By Wednesday morning…..the present upper ridge is flattened with the dominant upper ridge back at 170w. This retrogression in the long wave features actually coincides with progression in the long wave features next week. Since there is no blocking down stream at the moment, slow progression should continue into the weekend.

The screeming question is…. Will the cold upper trof  tap southern stream energy. Or….will there be southern stream energy to tap into?   Allot will depend upon “how far north the upper high builds into the Gulf of AK”  If the upper anti cyclone doesn’t get north enough into the gulf, southern stream energy probably won’t be much of a factor and we’ll just have a nice cold storm to deal with. 

Week Two:

Strong Blocking is really beginning to show it ugly head over Greenland by the the end of the month. The Dweebs have been waiting for it. The QBO has been growing more and more positive and thus stratospheric winds blowing west to east  at the Equator are strengthening. This is pretty common for La Nina Winters. The block and Negative NAO phase has the effect of really deepening the Hudson Bay Low and slowing the progression of storms into the west coast. Lets hope we get a bonanza of precipitation next weekend!

Stay Tuned……The Dweebs have you covered…………………………..:-)