000
FXUS66 KOTX 080939
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
239 AM PDT MON SEP 8 2008
.SYNOPSIS...
HIGH PRESSURE WILL BRING MOSTLY CLEAR SKIES AND SEASONABLY WARM
TEMPERATURES TO THE INLAND NORTHWEST TODAY. A VIGOROUS COLD FRONT
WILL MOVE THROUGH THE REGION LATE IN THE DAY ON TUESDAY. BREEZY
WINDS WILL ACCOMPANY THE PASSAGE OF THE COLD FRONT TUESDAY
EVENING...AND PORTIONS OF NORTHERN IDAHO AND NORTHEAST WASHINGTON
WILL HAVE THE CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.DISCUSSION...
TODAY AND TONIGHT...THE RIDGE OF HIGH PRESSURE AT 500MB OVER THE
EASTERN PACIFIC HAS EFFECTIVELY BEEN FLATTENED BY A POWERFUL
TROUGH OF LOW PRESSURE MOVING THROUGH THE GULF OF ALASKA. AS OF
09Z...THE OCCLUDED FRONT ASSOCIATED WITH THE GULF OF ALASKA TROUGH
WAS MOVING THROUGH NORTHERN BRITISH COLUMBIA. HIGH LEVEL MOISTURE
ALONG THIS DECAYING FRONT WILL SPILL INTO NORTHERN WASHINGTON
TODAY IN THE FORM OF CIRRUS. THE MAJORITY OF EASTERN WASHINGTON
AND NORTHERN IDAHO SOUTH OF INTERSTATE 90 WILL BE MOSTLY
SUNNY...AND THE CLOUDS OVER THE NORTHERN HALF OF THE STATE WILL
PROBABLY DO LITTLE TO INHIBIT WARMING TODAY. EXPECT TEMPERATURES
TO BE 2 TO 3 DEGREES WARMER TODAY THAN YESTERDAY COURTESY OF WEAK
WARM ADVECTION AT 850MB AHEAD OF THE DECAYING OCCLUDED FRONT.
/GKOCH
TUESDAY THROUGH SUNDAY...LITTLE CHANGES MADE HERE. LONGWAVE RIDGE
AXIS PLACEMENT OFF IN THE VICINITY OF THE GULF OF ALASKA MAINTAINS
A NORTHWEST FLOW IN WHICH A WELL RESOLVED SHORTWAVE DROPS DOWN
THROUGH EASTERN WASHINGTON AND NORTHERN IDAHO TUESDAY INTO TUESDAY
NIGHT. THE WAVES DEPARTURE ALLOWS IMPROVEMENT IN THE FORECAST
WEDNESDAY AS THE RIDGE IN THE VICINITY TAKES ON MORE OF A FLOP
OVER/POSITIVE TILT TO IT. THIS RIDGE STICKS AROUND TO ALLOW FOR
FURTHER IMPROVEMENT AND WARMING INTO THURSDAY BUT BY FRIDAY IT IS
FLATTENED OUT A BIT AND TAKES ON MORE OF A FLAT ZONAL FLOW
APPEARANCE...WHICH STOPS THE WARMING TREND AND ALLOWS FOR THE
POSSIBILITY OF SHORTWAVES MIGRATING THROUGH THE ZONAL FLOW TO
TRIGGER SOME LIGHT SHOWERS...WHICH ARE REINTRODUCED IN THE
FORECAST FOR FRIDAY AND SATURDAY. LATEST MODELS PROMOTE THE IDEA
OF RIDGE AMPLIFICATION AND PUSH THE ZONAL FLOW AWAY TO THE NORTHER
AND EAST SUNDAY SO A TENDENCY TOWARD A DRIER AND POSSIBLY WARMER
FORECAST IS MAINTAINED FOR THAT TIME INTERVAL. /PELATTI
WE WILL CONTINUE TO MONITOR THE POTENTIAL FOR STRONG WINDS THROUGH
THE OKANOGAN VALLEY AND OVER PORTIONS OF THE WATERVILLE PLATEAU LATE
IN THE DAY ON TUESDAY. THE TRACK AND INTENSITY OF THE TROUGH AT
500MB IS A FAMILIAR PATTERN FOR STRONG WINDS FOR THE VALLEYS OF
NORTHERN WASHINGTON. THE 850MB WINDS ON THE 00Z GFS (25-30KTS) ARE
PROBABLY UNDERDONE GIVEN THE STRENGTH AND ORIENTATION OF THE 250MB
JET (90KTS) DESCENDING OUT OF SOUTHERN BRITISH COLUMBIA. THE TIGHT
SURFACE PRESSURE GRADIENT ACROSS THE OKANOGAN VALLEY...AND DEEP
COLD AIR ADVECTION IN THE LOWER TROPOSPHERE ARE ALSO SIGNATURES
INDICATING THE POTENTIAL FOR STRONG WINDS IN OMAK AND OROVILLE.
WE WILL MENTION THE POTENTIAL FOR GUSTY WINDS IN THE HAZARDOUS
WEATHER OUTLOOK...AND EXAMINE THE MODELS FURTHER TODAY FOR THE
POTENTIAL OF A WIND ADVISORY. /GKOCH
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH 06Z
TUESDAY...AS HIGH PRESSURE BUILDS OVER THE INLAND NORTHWEST. FX
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 77 46 79 48 73 47 / 0 0 0 20 0 0
COEUR D`ALENE 76 43 78 47 72 45 / 0 0 0 20 0 0
PULLMAN 78 47 79 46 74 44 / 0 0 0 20 0 0
LEWISTON 84 52 84 54 80 51 / 0 0 0 10 0 0
COLVILLE 79 44 80 44 75 43 / 0 0 10 30 0 0
SANDPOINT 72 42 74 44 69 41 / 0 0 20 30 10 0
KELLOGG 75 42 74 46 69 46 / 0 0 0 30 10 0
MOSES LAKE 83 51 85 51 80 47 / 0 0 0 0 0 0
WENATCHEE 82 57 84 55 79 52 / 0 0 0 0 0 0
OMAK 83 51 84 49 80 48 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
