Getting Geeky

We're pretty set on the forecast for Sunday—see previous post—with just the wind the only possible wild card. But if you're interested in the underlying atmospheric dynamics, the new Forecast Area Discussion out of the Sacramento National Weather Service is a good one:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1005 AM PST FRI DEC 4 2009

.DISCUSSION...HIGHLY AMPLIFIED PATTERN OVER NOAM AND THE ERN PAC WILL BRING A CHANGE IN NORCAL WX THIS WEEKEND. DEEP LOW S OF HUDSON BAY /HUDSBA/ INTO THE MID SECTION OF THE U.S. EWD TO THE ERN SEABOARD...AND A STRONG RIDGE OVER THE ERN PAC HAS ALLOWED SHORT WAVE ENERGY THAT SPILLED OVER THE ERN PAC RIDGE TO FORM A CLOSED LOW OVER B.C. THIS SYSTEM HAS TAPPED INTO AIR FROM THE YUKON/B.C. PROVINCES WHERE IT WAS 1 BELOW TO 14 BELOW OVER MOST OF THE YUKON THIS MORNING...

THIS SHORT WAVE IS FORECAST TO MOVE INTO NV ON SAT DRAGGING A COLD FRONT ACROSS NERN CA. LOW LEVEL FLOW WILL TURN NELY OR UPSLOPE OVER THE E SLOPES SIERNEV...BUT WITH A LACK OF MOISTURE...NO SPILLOVER OF PCPN IS EXPECTED W OF THE SIERNEV CREST. THIS FRONT WILL GIVE NORCAL ITS FIRST COOLING TREND OF SOME 5 TO 6 DEG C AT 850 MBS AND AS MUCH AS 15 DAM THICKNESS COOLING OVER OUR NERN ZONES.