AREA FORECAST DISCUSSION

 
 FXUS66 KOTX 240335
 AFDOTX
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE SPOKANE WA
 735 PM PST MON NOV 23 2009
 
 .SYNOPSIS...
 WEAK PACIFIC WARM FRONT WILL BRING A POSSIBILITY OF VERY LIGHT
 PRECIPITATION TONIGHT...WITH GENERALLY DRY BUT CLOUDY WEATHER
 RETURNING TUESDAY AND THROUGH THANKSGIVING DAY. ON FRIDAY A COLD
 FRONT WILL PASS THROUGH WITH ANOTHER REASONABLE CHANCE OF MOUNTAIN
 SNOW AND VALLEY RAIN OR SNOW. CONDITIONS WILL REMAIN CLOUDY AND
 UNSETTLED INTO NEXT WEEKEND.
 
 &&
 
 
 .DISCUSSION...
 SATELLITE THIS EVENING SHOWS AN UPPER TROUGH PASSING BY NORTH OF
 THE INLAND NW ACROSS BRITISH COLUMBIA AND ALBERTA. THE SOUTHERN
 MOST PORTION OF THIS SYSTEM IS EXPECTED TO DRAG A WEAK WARM FRONT
 ACROSS THE AREA TONIGHT. A PRECIPITABLE WATER FETCH WITH VALUES
 OFF THE COAST JUST OVER AN INCH IS AIMED EARLY THIS EVENING AT
 NORTHERN WASHINGTON. THIS AREA WILL SLOWLY SAG SOUTH TONIGHT WITH
 THE WARM FRONT PASSAGE. ISENTROPIC LIFT AS THE FRONT PASSES WILL
 RESULT IN INCREASING PRECIPITATION CHANCES FROM NORTH TO SOUTH.
 BEST THREAT OF LIGHT PRECIPITATION WILL FALL IN THE OROGRAPHICALLY
 FAVORED AREAS OF THE CASCADE CREST AND THE MOUNTAINS OF NE WA/N
 IDAHO WHERE UPSLOPE FLOW WILL OCCUR WHILE DOWNSLOPE FLOW OFF THE
 CASCADES WILL KEEP POPS ONLY AT 20 PCT FOR WENATCHEE AND MOSES
 LAKE. CURRENT SATELLITE TRENDS SHOW A SLIGHTLY SLOWER PROGRESSION
 THAN EARLIER THOUGHT SO POPS WERE TRENDED DOWN THIS EVENING ALONG
 THE INTERSTATE 90 CORRIDOR FROM SPOKANE TO LOOKOUT PASS. ALSO
 LOWERED POPS FOR LEWISTON AND WINCHESTER OVERNIGHT BASED ON THE
 SLOWER PROGRESSION. 1000-850MB THICKNESSES OF 1300-1310DM OVER NE
 WA/N IDAHO AND 850MB TEMPS OF -2 TO -4C WILL SUPPORT SNOW LEVELS
 CLOSE TO 2000 FEET. JW
 
 &&
 
 .AVIATION...
 A WEAK WARM FRONT WILL MOVE INTO NORTHERN WA AND THE ID PANHANDLE 
 TONIGHT RESULTING IN SCT RA/SN SHOWERS. HOWEVER...SOME UNCERTAINTY 
 EXISTS ON WHETHER OR NOT PRECIP...AND SUBSEQUENT MVFR CIGS...WILL 
 REACH THE KGEG-KCOE CORRIDOR LATE TONIGHT. LIGHT UPSLOPE WINDS MAY 
 ALLOW LOW STRATUS TO DEVELOP IN THE KGEG-KCOE AREA AFTER 10Z 
 TUESDAY. 
 
 
 &&
 
 .PRELIMINARY POINT TEMPS/POPS...
 SPOKANE        33  40  33  40  32  40 /  40  10   0   0   0  10 
 COEUR D`ALENE  31  39  32  41  32  40 /  50  20   0   0   0  10 
 PULLMAN        31  41  31  44  33  43 /  50  20   0   0   0   0 
 LEWISTON       34  47  35  48  35  48 /  20  20   0   0   0   0 
 COLVILLE       32  41  31  40  31  42 /  60  10  20  10  30  30 
 SANDPOINT      31  36  29  39  29  40 /  60  30   0  10  10  10 
 KELLOGG        29  37  31  40  30  40 /  60  40  20   0   0   0 
 MOSES LAKE     32  46  32  43  31  41 /  20   0   0   0   0  10 
 WENATCHEE      34  44  34  41  33  39 /  20  10   0   0  10  20 
 OMAK           31  44  31  43  32  42 /  50  10  10  10  20  30 
 
 &&
 
 .OTX WATCHES/WARNINGS/ADVISORIES...
 ID...NONE.
 WA...NONE.
 &&
 
 $$