FXUS66 KOTX 231813
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1013 AM PST WED DEC 23 2009
.SYNOPSIS...
THE UPPER LEVEL TROUGH OF LOW PRESSURE WHICH IMPACTED THE
INLAND NORTHWEST YESTERDAY WILL SHIFT INTO EASTERN MONTANA THIS
AFTERNOON. MEANWHILE...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...
FEW CHANGES HAVE BEEN MADE TO THE FORECAST FOR THE REMAINDER OF
THE DAY. THE 18Z SURFACE ANALYSIS OF THE WESTERN UNITED STATES
SHOW A POTENT ARCTIC COLD FRONT PLUNGING THROUGH MONTANA INTO THE
DAKOTAS. EASTERN WASHINGTON AND NORTHERN IDAHO HAVE RECEIVED A
GLANCING BLOW FROM THIS FRONT. MODIFIED ARCTIC AIR CONTINUES TO
SPILL THROUGH THE OKANOGAN VALLEY. SURFACE DEWPOINTS HAVE FALLEN
INTO THE SINGLE DIGITS AND LOW TEENS OVER MUCH OF NORTH CENTRAL
WASHINGTON. THE DRY AIR HAS SPREAD OVER MUCH OF THE SPOKANE
FORECAST AREA. SOUTHEAST WASHINGTON AND ADJACENT PORTIONS OF THE
IDAHO PANHANDLE ARE THE LAST SPOTS TO REMAIN IN THE LOW CLOUDS.
THE CONTINUATION OF DRY ADVECTION THROUGH THE AFTERNOON SHOULD
DISSIPATE MOST OF THE LOW CLOUDS IN THE PULLMAN AND LEWISTON AREAS
THIS AFTERNOON. INFRARED SATELLITE IMAGERY SHOWS CLOUD TOPS OVER
THE CENTRAL AND SOUTHERN PANHANDLE IN THE -15 TO -20C
RANGE...WHICH IS SUFFICIENTLY COLD FOR THE FORMATION OF SNOW
FLAKES. BY THIS AFTERNOON...DRY ADVECTION WILL LIKELY BRING AN END
TO ANY CHANCES FOR LIGHT SNOW. /GKOCH
&&
.AVIATION...
DRY AIR WILL CONTINUE TO ERODE THE LOW CLOUDS OVER SOUTHEAST
WASHINGTON AND ADJACENT PORTIONS OF THE CENTRAL AND SOUTHERN IDAHO
PANHANDLE THIS AFTERNOON. LOOK FOR CLOUDS TO SCATTER IN THE
PULLMAN AND LEWISTON AREAS BETWEEN 21Z-00Z. THE AIR MASS OVER
EASTERN WASHINGTON AND NORTHERN IDAHO WILL LIKELY BE TOO DRY FOR
THE FORMATION OF FOG TONIGHT...BUT SOME RAGGED STRATUS MAY
REDEVELOP LATE TONIGHT AND EARLY THURSDAY MORNING AT
LEWISTON...SPOKANE...AND WENATCHEE. /GKOCH
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 29 12 23 14 26 17 / 0 0 0 0 0 0
COEUR D'ALENE 30 13 24 15 27 16 / 0 0 0 0 0 0
PULLMAN 32 16 25 17 30 19 / 10 0 0 0 0 0
LEWISTON 36 20 30 19 29 19 / 10 0 0 0 0 0
COLVILLE 30 9 25 12 27 15 / 0 0 0 0 0 0
SANDPOINT 29 11 22 13 25 13 / 10 0 0 0 0 0
KELLOGG 28 12 22 13 25 12 / 10 0 0 0 0 0
MOSES LAKE 31 14 27 13 27 13 / 0 0 0 0 0 0
WENATCHEE 31 19 27 19 26 18 / 0 0 0 0 0 0
OMAK 28 10 24 10 25 15 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
