FXUS66 KOTX 241902
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1102 AM PST THU DEC 24 2009
.SYNOPSIS...
STRONG HIGH PRESSURE WILL GRADUALLY BUILD OVER THE PACIFIC NORTHWEST.
THIS RIDGE IS EXPECTED TO PERSIST THROUGH NEXT WEEK...RESULTING IN
LITTLE IF ANY CHANCE OF MEASURABLE PRECIPITATION. IT WILL ALSO
BRING INCREASING CHANCES FOR FOG AND LOW CLOUDS IN THE VALLEYS.
&&
.DISCUSSION...
THERE ARE PATCHES OF LOW CLOUDS THROUGHOUT THE COLUMBIA
BASIN...THE PALOUSE...AND AROUND THE SPOKANE AREA. THE MORNING
SOUNDING FROM SPOKANE HAD A WEAK INVERSION WITH A HEIGHT BETWEEN
1000-1500 FEET. THE SUN IS NOT VERY POTENT THIS TIME OF YEAR...BUT
SOME OF THIS CLOUDINESS SHOULD ERODE THIS AFTERNON. AS OF 18Z...
THE AXIS OF THE UPPER LEVEL RIDGE WAS ALONG THE WASHINGTON COAST.
BY TONIGHT...THE RIDGE WILL SPREAD INLAND WHICH WILL STRENGTHEN
THE LOW LEVEL INVERSION. SO THE LOW CLOUDS AND FOG THAT DEVELOP
TONIGHT AND EARLY TOMORROW MORNING WILL BE MUCH MORE DIFFICULT TO
DISPERSE. BOUNDARY LAYER MOISTURE AND WIND PROGS SUGGEST THAT THE
BEST POTENTIAL FOR WIDESPREAD FOG AND STRATUS DEVELOPMENT TONIGHT
WILL BE ALONG THE EAST SLOPES...THE WENATCHEE AREA...AND THE
SOUTHERN BASIN. THE SHELTERED VALLEYS OF NORTHERN WASHINGTON MAY
SEE FOG DEVELOPMENT AS WELL. WE WILL MONITOR SURFACE DEWPOINTS
THIS AFTERNOON AROUND COLVILLE...BONNERS FERRY...AND PRIEST RIVER.
IF THEY CAN CLIMB UP AROUND 20F...CHANCES FOR FOG DEVELOPMENT
TONIGHT WILL INCREASE SIGNIFICANTLY. /GKOCH
&&
.AVIATION...
PATCHES OF STRATUS WILL HAVE AN IMPACT ON AVIATION THURSDAY
AFTERNOON AND THURSDAY EVENING. LOW CLOUDS ARE NOT WIDESPREAD...
BUT WILL PRODUCE CEILINGS AROUND 3000 FEET IN THE WENATCHEE
AREA...AND CEILINGS AROUND 2000 FEET IN THE SPOKANE VICINITY. SOME
EROTION OF THESE LOW CLOUDS IS LIKELY BETWEEN 21Z-00Z. HIGH
PRESSURE WILL BUILD OVERNIGHT STRENGTHENING THE LOW LEVEL
INVERSION. REDEVELOPMENT OF LOW CLOUDS IS LIKELY BETWEEN 06Z-15Z
OVER THE MAJORITY OF THE LOW ELEVATIONS WITH CEILINGS BELOW 1500
FEET. /GKOCH
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 24 14 26 17 29 21 / 0 0 0 0 0 0
COEUR D'ALENE 25 15 27 16 28 20 / 0 0 0 0 0 0
PULLMAN 28 19 30 21 29 22 / 0 0 0 0 0 0
LEWISTON 31 20 32 23 32 23 / 0 0 0 0 0 0
COLVILLE 28 15 27 15 29 20 / 0 0 0 0 0 0
SANDPOINT 25 14 25 13 28 18 / 0 0 0 0 0 0
KELLOGG 23 14 25 12 27 19 / 0 0 0 0 0 0
MOSES LAKE 26 16 29 16 29 21 / 0 0 0 0 0 0
WENATCHEE 27 20 26 20 29 22 / 0 0 0 0 0 0
OMAK 26 14 25 15 28 19 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...AIR STAGNATION ADVISORY UNTIL 4 PM PST SATURDAY FOR CENTRAL
PANHANDLE MOUNTAINS...COEUR D'ALENE AREA...IDAHO PALOUSE...
LEWIS AND SOUTHERN NEZ PERCE COUNTIES...LEWISTON AREA...
NORTHERN PANHANDLE.
WA...AIR STAGNATION ADVISORY UNTIL 4 PM PST SATURDAY FOR EAST SLOPES
NORTHERN CASCADES...LOWER GARFIELD AND ASOTIN COUNTIES...
MOSES LAKE AREA...NORTHEAST MOUNTAINS...OKANOGAN
HIGHLANDS...OKANOGAN VALLEY...SPOKANE AREA...UPPER COLUMBIA
BASIN...WASHINGTON PALOUSE...WATERVILLE PLATEAU...WENATCHEE
AREA.
&&
$$
