FXUS66 KOTX 050121
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
521 PM PST FRI DEC 4 2009
.SYNOPSIS...
LIGHT SNOW SHOWERS...BLUSTERY NORTH WINDS AND COLDER TEMPERATURES
WILL DESCRIBE THE WEATHER ACROSS THE INLAND NORTHWEST THIS WEEKEND...
AS A PAIR OF COLD UPPER LEVEL DISTURBANCES MOVES THROUGH THE
REGION. THEN DRY AND UNSEASONABLY COLD WEATHER WILL PERSIST FOR
MUCH OF NEXT WEEK.
&&
.DISCUSSION...
UPDATE FOR TONIGHT...RADAR RETURNS HAVE BECOME MUCH MORE NUMEROUS
OVER THE LAST HOUR AROUND THE NORTHEAST MOUNTAINS AND NORTHERN
SPOKANE AREA. THIS IS LIKELY DUE TO THE BEAM OVERSHOOTING THE BULK
OF THE SNOWFALL THAT IS OCCURRING FARTHER FROM THE RADAR. MODEL
DEPICTIONS OF THE MOIST LAYER FROM WHICH SNOWFALL IS ORIGINATING
INDICATE THAT IT IS GENERALLY FALLING FROM ABOUT 10000 FEET OR
LOWER...SO THIS REALLY IS NO SURPRISE. HOWEVER...THE WIDESPREAD
NATURE OF THE RETURNS IS A BIT MORE THAN HAD BEEN ANTICIPATED. AS
A RESULT...THE FORECAST HAS BEEN UPDATED TO DEPICT NUMEROUS LIGHT
SNOW SHOWERS AND FLURRIES THIS EVENING ACROSS THE EASTERN HALF OF
THE FORECAST AREA WITH THE FIRST COLD NORTHERLY SURGE SPREADING
SOUTHWARD THIS EVENING. ADDITIONALLY...LOW LEVEL FLOW TURNING
NORTHWEST TO NORTH SHOULD ALLOW UPSLOPE SNOW SHOWERS TO COMMENCE
OVER THE NORTHERN BLUE MOUNTAINS AND CAMAS PRAIRIE TOWARD MORNING.
DUE TO THE MOIST LAYER BASICALLY BEING RESTRICTED TO BELOW 750
MB...AND THE FACT THAT THE LAYER OF OMEGA IS NOT VERY
DEEP...NOTHING HORRIBLY IMPRESSIVE IS EXPECTED. HOWEVER...THE
SHALLOW OMEGA IS CO-LOCATED WITH THE DENDRITIC GROWTH ZONE AND
NEAR -13C...SO POPS WERE UPPED ACROSS THE CAMAS PRAIRIE AND BLUE
MOUNTAINS WITH LIGHT ACCUMULATIONS EXPECTED THROUGH SATURDAY
MORNING. /FRIES
&&
.AVIATION...
RATHER DIFFICULT AND LOW CONFIDENCE AVIATION FORECAST DURING THE
NEXT 24 HRS. THROUGH 18Z SAT WE EXPECT TO PRIMARILY SEE IFR/MVFR
CIGS FROM A WDSPRD DECK OF LOW CLOUDS. THESE CLDS ARE MAINLY
IMPACTING THE EASTERN TAF SITES AND SPARING KMWH AND KEAT. WHILE WE
EXPECT THE LOW CLOUDS TO PERSIST THRU AT LEAST THRU 18Z SAT THE
WEATHER WILL BE FURTHER COMPLICATED BY A WEAK UPPER LEVEL
DISTURBANCE DIVING SOUTH FROM BC. THIS SYSTEM WILL LIKELY PRODUCE
SOME FLURRIES OR -SHSN AS IT DROPS INTO THE REGION. WHETHER THIS
WILL BREAK UP THE LOW CLOUDS OR NOT IS PROBLEMATIC. WE SUSPECT SINCE
IT IS FAIRLY WEAK THE LOW CIGS WILL REMAIN INTACT...BUT CIGS SHOULD
LOWER AT KEAT AND KMWH. WE EXPECT MOST CONDITIONS TO IMPROVE TO VFR
AFT 20Z...HOWEVER PATCHY MVFR CIGS WILL LIKELY PERSIST NR THE OR-WA
BORDER. FX
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 18 29 14 18 4 11 / 20 20 10 10 0 0
COEUR D'ALENE 20 31 13 17 2 10 / 20 20 10 10 0 0
PULLMAN 20 28 15 20 6 14 / 30 20 10 0 0 0
LEWISTON 22 33 18 26 11 19 / 30 20 10 0 0 0
COLVILLE 23 33 16 21 4 13 / 20 20 40 10 0 0
SANDPOINT 21 30 10 13 -1 6 / 30 20 20 10 0 0
KELLOGG 20 27 9 14 -1 7 / 50 40 10 10 10 0
MOSES LAKE 20 32 15 24 5 16 / 10 10 20 10 0 0
WENATCHEE 23 34 16 23 7 16 / 0 10 60 10 10 0
OMAK 20 33 15 23 5 17 / 0 20 70 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
