FXUS66 KOTX 281753
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
953 AM PST SAT NOV 28 2009
.SYNOPSIS...
CLOUDS WILL INCREASE TODAY AND PORTIONS OF NORTHERN WASHINGTON AND
FAR NORTHERN IDAHO WILL EXPERIENCE SOME LIGHT SNOW THIS AFTERNOON
AND THIS EVENING. HIGH PRESSURE WILL BE THE DOMINANT WEATHER
FEATURE OVER THE PACIFIC NORTHWEST FOR MOST OF NEXT WEEK. LOOK FOR
MAINLY DRY WEATHER AND CHILLY TEMPERATURES.
&&
.DISCUSSION...
TODAY...WE'VE MADE ONLY MINOR CHANGES TO THE FCST FOR TODAY...FOCUSING
ON THE AREAL COVERAGE OF FOG AND STRATUS. METAR OBS STILL SHOW
SEVERELY-RESTRICTED VSBYS FROM MOSES LAKE E TO SPOKANE INCLUDING
THE I-90 CORRIDOR. THE 12Z OTX RAOB SHOWS THE SFC MOIST LYR DEPTH
LESS THAN ONE THOUSAND FT...WITH A TEMP PROFILE SUPPORTING
DRIZZLE/FZDZ. WE'VE BEEN HANDLING THIS WITH NOWCASTS GIVEN THE
LESS-THAN-WIDESPREAD COVERAGE. SATELLITE LOOPERS SHOW A WELL-
DEFINED BACK EDGE TO THE DECK OF STRATUS JUST N OF KPUW TO NEAR
KMWH...SLOWLY CREEPING N. FCST SOUNDINGS SHOW THE DRY S.E. FLOW AT
LEAST PARTLY RESPONSIBLE FOR THIS CLEARING LINE MOVING N
TODAY...WITH THE BACK EDGE MOVING TO JUST S OF SPOKANE.
HOWEVER...FCST SOUNDINGS SHOW A SLOW DEEPENING OF THE STRATUS DECK
WITHIN PERSISTENT S/SE FLOW FOR THE SPOKANE AREA. THIS SUPPORTS A
CLOUDY...AND OCCASIONALLY FOGGY FCST...ALL DAY THAT INCLUDED
PATCHES OF DRIZZLE. ALOFT...WE'LL SEE A THICKENING CANOPY OF MID-
CLOUD AND A MOISTENING OF THE MID-LEVEL DRY LYR ABOVE THE STRATUS
DECK AS LIGHT PCPN SLOWLY SATURATES THE LYR. BY THIS AFTERNOON THE
DEPTH OF THE DRY LYR WILL SHRINK TO BETWEEN 5 AND 10K
FT...SUFFICIENT TO PRODUCE FLURRIES EVEN FOR LOWER ELEVS N OF
SPOKANE. THIS PCPN MAY ALSO SEED THE SFC FOG DECK TO PRODUCE A
CHANCE OF LIGHT SNOW AS FAR S AS SPOKANE AND WEST TO NEAR KOMK.
THIS IS ALREADY COVERED IN THE MORNING FCST. NO OTHER NOTES OF
SIGNIFICANCE. BZ
&&
.AVIATION...
THE LIFR CEILINGS/VSBY FROM KGEG TO KMWH HAVE BEGUN THE PROCESS
OF DISSIPATION...WITH KMWH AND KGEG IMPROVING TO 2 MILES VSBY. THE
BACK EDGE OF A WELL-DEFINED STRATUS DECK STRETCHING FROM 35 S OF
KGEG TO NEAR KMWH IS EXPECTED TO MOVE SLOWLY N AND IMPROVE THE WX
TO VFR FOR KMWH AND MVFR FOR SPOKANE. HOWEVER...THE VSBL SATELLITE
LOOPER ALREADY SHOWS REGENERATION OF LOW CEILINGS WITHIN THE SUNNY
REGION BETWEEN KPUW AND KGEG FROM SFC HEATING. BECAUSE OF
THIS...WE'VE TAKEN A CONSERVATIVE APPROACH AS FAR AS IMPROVING THE
WX TO VFR FOR THE SPOKANE AREA. THE GOOD NEWS IS THAT THE THREAT
OF PERSISTENT 1/2 MILE VSBYS AND FZFG FOR SPOKANE HAS ESSENTIALLY
ENDED. BZ
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 36 31 40 31 40 29 / 10 10 0 0 0 10
COEUR D'ALENE 36 31 39 32 42 30 / 20 20 10 0 0 20
PULLMAN 37 30 43 32 43 31 / 0 10 0 0 0 10
LEWISTON 43 32 48 34 45 34 / 0 10 0 0 0 10
COLVILLE 36 32 40 33 40 31 / 20 20 10 10 10 30
SANDPOINT 35 30 36 32 38 30 / 20 20 20 10 10 30
KELLOGG 33 31 36 32 40 29 / 20 20 20 10 10 20
MOSES LAKE 41 31 45 32 41 29 / 0 10 0 0 0 0
WENATCHEE 43 34 48 34 42 33 / 0 10 0 0 0 10
OMAK 40 31 43 33 42 30 / 10 10 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
