Expires:No;;260280 FXUS66 KOTX 261031 AFDOTX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 231 AM PST THU NOV 26 2009 .SYNOPSIS... A MOIST PACIFIC STORM SYSTEM WILL BRING LIGHT RAIN TO LOCATIONS NEAR THE CASCADES BY THIS AFTERNOON...WHILE HOLDING OFF UNTIL TONIGHT OVER FAR EASTERN WASHINGTON AND THE IDAHO PANHANDLE...AND LINGERING INTO FRIDAY MORNING. AFTER THAT GENERALLY DRY AND SEASONABLY COOL CONDITIONS WILL BEGIN EXCEPT FOR SCATTERED MOUNTAIN SNOW SHOWERS THROUGH THE WEEKEND. A SIGNIFICANT COOLING TREND IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .DISCUSSION... SATELLITE INDICATES AN INCOMING PACIFIC STORM THIS MORNING...WHICH IS SPREADING RAIN OVER THE WEST SIDE AND WILL GRADUALLY CREEP OVER THE CASCADES TODAY AND THROUGH THE FORECAST AREA TONIGHT. MODELS ARE RELATIVELY SIMILAR WITH MINOR FRONT TIMING ISSUES...BUT IN OVERALL AGREEMENT FOR THE NEXT 24 TO 36 HOURS. THE DEEP PACIFIC TROUGH EVIDENT ON SATELLITE JUST OFF THE COAST WILL PUSH A VERY MOIST BAROCLINIC REGION THROUGH THE FORECAST AREA TONIGHT AND INTO FRIDAY MORNING. FREEZING LEVELS WILL REMAIN QUITE HIGH WITH THIS SYSTEM...WITH SIGNIFICANT ACCUMULATING SNOW LIMITED TO ABOVE MOST PASS ELEVATIONS. OVER THE WESTERN ZONES AND NORTH OF THE COLUMBIA BASIN A GRADUAL THICKENING OF CLOUDS IS EXPECTED TODAY WITH AN ONSET OF VALLEY LIGHT RAIN AND HIGH MOUNTAIN SNOW SOMETIME IN THE AFTERNOON. OVER THE EASTERN HALF OF THE FORECAST AREA THE DAY WILL START WITH INVERSION CONDITIONS IN FOG AND STRATUS FIELDS...MARGINALLY IMPROVING BY AFTERNOON AND WITH THICKENING MID LEVEL CLOUDS ABOVE THE LOW LEVEL STRATUS. TONIGHT THE FRONTAL BAND WILL PASS THROUGH MOST OF THE FORECAST AREA WITH A ROUND OF LIGHT TO MODERATE VALLEY RAIN AND MOUNTAIN SNOW...EXITING TO THE EAST FRIDAY MORNING. PRECIPITATION AND HEAVY CLOUDS WILL KEEP MOST LOCATIONS WELL ABOVE FREEZING TONIGHT FOR LITTLE WORRY ABOUT ANY FROZEN ROAD SURFACES FOR THE FRIDAY MORNING COMMUTE. ON FRIDAY THE FRONTAL BAND WILL SCOOT OUT OF THE REGION...WITH SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST. THIS PATTERN WILL ALLOW SOME CLEARING SKIES FROM WEST TO EAST DURING THE DAY...WITH BREEZY AND SLIGHTLY COOLER CONDITIONS AS COLD AIR BEGINS TO EXCHANGE THE STAGNANT BASIN AIR MASS OF THE PAST FEW DAYS. /FUGAZZI FRIDAY NIGHT THROUGH WEDNESDAY...THE INLAND NW REMAINS IN A SEMI- AMPLIFIED PATTERN...WITH THE NEXT AREA-WIDE CHANCE OF PRECIPITATION ARRIVING WITH A SYSTEM LATE MONDAY...BEFORE COLDER AIR COMES IN. FRIDAY NIGHT THE DEEPER MID-LEVEL TROUGH PULLS EAST AS A NW FLOW DEVELOPS...AND A MORE COMPACT MID-LEVEL DISTURBANCE MOVES BY OVERNIGHT INTO SATURDAY. AT PRESENT MODELS HAVE TRENDED FURTHER NORTH WITH ITS TRACK...REDUCING THE RISK OF PRECIPITATION. THE MAIN CHANCE FOR SNOW SHOWERS LAYS IN THE CASCADES AND THE IDAHO PANHANDLE THROUGH THE BLUES. YET IT STILL BEARS WATCHING...SHOULD THE FEATURE REVERT TO A TRACK THAT BRINGS IT MORE DIRECTLY OVER THE AREA. A RIDGE BUILDS IN SATURDAY NIGHT INTO MONDAY. IT IS LED BY A WEAK WARM FRONT WHICH WILL KEEP A LIGHT SHOWER RISK GOING ACROSS THE MOUNTAIN ZONES...WHILE PROMOTING VALLEY STRATUS AND FOG. THE NEXT SYSTEM COMES IN MONDAY NIGHT AND TUESDAY. THIS WILL ELEVATE THE RISK FOR SHOWERS AREA-WIDE. MILDER AIR SURGING AHEAD OF IT WILL ALLOW FOR A RISK OF RAIN AND SNOW SHOWERS MONDAY NIGHT...BEFORE COLDER AIR STARTS IN OVERNIGHT. A NW FLOW DEVELOPS BY TUESDAY AND CONTINUES INTO WEDNESDAY AS A RIDGE DEVELOPS OFFSHORE. THIS PUSHES THE MAIN PRECIPITATION CHANCES TO THE IDAHO PANHANDLE AND DROPS TEMPERATURES ACROSS MUCH OF THE REGION TO SLIGHTLY BELOW NORMAL. THERE IS SOME DISAGREEMENT ON HOW FAR EAST THE RIDGE AXIS PROGRESSES. THE ECMWF/GEM/GEFS HOLD IT OFFSHORE. THE GFS BRINGS IT ONTO THE CASCADES. IF THE GFS VERIFIES THIS WOULD ALLOW FOR MILDER TEMPERATURES OVER THE WESTERN CWA THAN CURRENTLY FORECAST. HOWEVER AS THE GFS SEEMS LIKE THE OUTLIER THE COLDER SOLUTION IS PREFERRED. /JCOTE && .AVIATION... FOG HAS ALREADY FORMED AND WILL PERSIST INTO THE LATE MORNING HOURS OF THANKSGIVING AROUND KGEG AND KCOE...WITH THE FOG EXTENDING OVER KSFF AS STRATUS. MOST OTHER SITES WILL SEE STRATUS CONTINUE THROUGH THE NEXT 24 HOURS AS THE NEXT SYSTEM APPROACHES FROM THE WEST AFTER 26/21Z. -RA WILL MOVE THROUGH KEAT AND KMWH BY THE AFTERNOON OF THURSDAY...AND MOVE EASTWARD FROM THERE AFTER THAT TIME. FOG WILL BE SLOW TO BURN DUE TO INCOMING MID-CLOUDS...SO EXPECT VLIFR CONDITIONS TO PERSIST IN SPOTS WITH FOG THROUGH AT LEAST 26/19Z. /FRIES && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 43 36 40 29 36 29 / 10 70 70 10 10 10 COEUR D'ALENE 43 35 42 29 37 30 / 10 80 70 20 20 20 PULLMAN 48 36 42 28 36 29 / 10 40 80 30 10 10 LEWISTON 53 39 48 34 42 33 / 10 40 60 30 10 10 COLVILLE 43 34 42 27 38 31 / 20 70 70 10 10 20 SANDPOINT 45 35 38 27 33 30 / 10 70 80 30 20 20 KELLOGG 44 35 37 30 32 29 / 10 60 90 50 30 30 MOSES LAKE 44 34 46 28 43 29 / 20 50 10 10 10 0 WENATCHEE 45 34 47 31 44 33 / 30 60 10 10 10 0 OMAK 44 33 45 26 42 30 / 50 70 20 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...NONE. WA...NONE. && $$