FXUS66 KOTX 292324 AAA
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
324 PM PST SUN NOV 29 2009
.SYNOPSIS...
THE PASSAGE OF ANOTHER QUICK MOVING COLD FRONT MONDAY NIGHT WILL
PRODUCE SOME MOUNTAIN SNOWS FOR NORTH IDAHO AND BRIEF GUSTY NORTH
WINDS TUESDAY. FOLLOWING THIS...LOOK FOR MAINLY DRY CONDITIONS...
CHILLY TEMPERATURES...AND AREAS OF LOW CLOUDS AND FOG THE REST OF
THE WEEK.
&&
.DISCUSSION...
TONIGHT AND MONDAY...RIDGING ALOFT OVER EASTERN WASHINGTON AND
NORTHERN IDAHO WEAKENS INTO MONDAY AS THE AXIS MOVES EAST AND A
SHORTWAVE TROF APPROACHES FROM THE NORTHWEST. AS THE RIDGE IS NOT
ALL THAT AMPLIFIED TO BEGIN WITH HIGHER LEVEL MOISTURE STREAMING
THROUGH IT WILL ADD NUISANCE TO THE ONGOING STRATUS/FOG ISSUES
FOUND AT THE LOWER LEVELS AS THE WEAK SUBSIDENCE TAKES PLACE UNDER
THE RIDGE. POPS REMAIN QUITE LOW AND SHOW A VERY GRADUAL INCREASE
ON MONDAY TO HINT AT THE EARLIER MENTIONED APPROACH OF THE
SHORTWAVE TROF FROM THE NORTHWEST. THE DISCUSSED SUBSIDENCE
INVERSION...AND SOMEWHAT MODERATE SOUTHERLY FLOW...REFLECTED IN
DEWPOINT READINGS GENERALLY IN THE MIDDLE 30S...SHOULD RESULT IN
FORECAST TEMPS A FEW DEGREES ON THE WARM SIDE OF CLIMO. /PELATTI
MON NIGHT THRU WED...THE FOCUS WILL BE ON FROPA MON NT AS A QUICK-
MOVING FRONT TRACKS OUT OF BC MON AND INTO ERN WA MON NT. THIS
LOOKS LIKE ANOTHER EVENT WHERE THE MID-LEVEL DRY SLOT AXIS IS
DIRECTLY OVER THE COLUMBIA BASIN AND THE JET AXIS AND VORT MAX
MOVE S.E. ACROSS NW MT...BARELY CLIPPING THE PANHANDLE. THIS SHOULD
PUT THE HIGHEST CHANCE OF PCPN IN THE ID PANHANDLE WITH DRY WX
IMMEDIATELY TO THE W. THOUGH WE DON'T HAVE A WHOLE OF SYNOPTIC-
SCALE ASCENT OVER THE SE WA AND CNTRL ID PANHANDLE REGION ON THE
BACK SIDE OF THE FRONT TUES...WE'RE MAINTAINING A PERSISTENT W/NW
FLOW FROM THE SFC TO 750MB IN A LYR THAT'S CONVECTIVELY UNSTABLE
AND UNDERGOING OROGRAPHIC ASCENT. ITS NOT UNTIL AFTER 18Z THAT
THIS FLOW WEAKENS AND BACKS TO THE SW...SHUTTING OFF THE PCPN.
THAT SAID... WE LINGERED THE THREAT OF POST-FRONTAL SHOWERS WELL
INTO TUES FOR THE ID PANHANDLE MTNS...BUT WITH ONLY MINOR
ACCUMULATIONS. A RATHER DRY AIRMASS WILL THEN WORK ITS WAY OUT OF
BC AND INTO THE REGION AS THE SFC HI WEAKENS OVER S.E. BC. THOUGH
PRESSURE RISES AREN'T IMPRESSIVE...WE INCREASED WIND SPEEDS AND
GUSTS DOWN THE OKANOGAN VLY TUES. FOLLOWING COLD LOW TEMPS TUES
NT...THE NEXT WARMFNT WILL PRODUCE AN INCREASE IN CLOUDS AND
LIGHT SNOW THREAT WED...NOT UNLIKE THE LAST COUPLE WARMFNT PCPN
EVENTS THE LAST FEW DAYS. BZ
WEDNESDAY NIGHT TO SUNDAY...MODEL AGREEMENT AND CONSISTENCY IS FAIR.
THE ECMWF IS THE BIGGEST OUTLIER. LOOSE AGREEMENT FROM OTHER GUIDANCE
(GFS/GFS ENSEMBLE/GEM/DGEX) BRINGS A SYSTEM BY THURSDAY/FRIDAY...WITH
THE NEXT BEST CHANCE OF RAIN AND SNOW...FOLLOWED BY A COLDER AND DRIER
NORTHERLY FLOW AS A RIDGE DEVELOPS OFFSHORE NEXT WEEKEND. THIS LEADS
TO A REDUCTION OF THE PRECIP THREAT AND BELOW NORMAL TEMPS. /JCOTE
&&
.AVIATION...
HIGH PRESSURE WILL CONTINUE TO PROMOTE FOG/STRATUS DEVELOP TONIGHT
AND EARLY MONDAY BEFORE A SHORT-WAVE TROUGH COMES IN. LCL MVFR/LIFR
CIGS WILL BE POSSIBLE AROUND KGEG-KCOE AND KMWH-KEAT BTWN 10-18Z.
/JCOTE
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 29 41 29 37 23 36 / 0 0 10 0 0 0
COEUR D'ALENE 32 41 30 37 22 37 / 0 0 10 0 0 0
PULLMAN 30 42 33 40 26 39 / 0 0 10 10 0 0
LEWISTON 32 46 36 42 29 44 / 0 0 10 10 0 0
COLVILLE 36 41 27 37 22 36 / 0 10 20 0 0 0
SANDPOINT 33 37 28 35 21 33 / 10 10 20 10 0 10
KELLOGG 29 39 30 36 26 34 / 0 10 20 10 0 10
MOSES LAKE 28 43 30 41 25 39 / 0 0 0 0 0 0
WENATCHEE 32 44 31 42 29 39 / 0 0 0 0 0 0
OMAK 32 43 28 40 24 40 / 0 0 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
