Heavy Snow in Washington, January 14, 2001

EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WASHINGTON
230 AM PST SUN JAN 14 2001

THE END TO THE PRECIPITATION ASSOCIATED WITH A WEAK TROF OVER THE PAC
NW IS IN SIGHT. WATER VAPOR LOOP AND MODELS ALL DEPICT SOME SORT OF
SHORTWAVE ROTATING THROUGH EAST CENTRAL WA...SW OF SPOKANE. RADAR
LOOP CONFIRMS THIS ROTATION AND LOCATION. ANOTHER SHORTWAVE WAS
LOCATED NEAR BANFF. THESE FEATURES WILL BECOME LESS IMPORTANT THROUGH
THE DAY AS OFFSHORE RIDGE WILL SHIFT A LITTLE FARTHER
INLAND...TURNING THE MID TROPOSPHERIC FLOW MORE NORTHERLY WITH TIME.
THIS SHIFTING FLOW WILL BRING A GRADUAL DRYING TREND AND SHOULD PUSH
MOST OF THE PRECIPITATION AND SHORTWAVE SOUTH OF THE REGION. IN THE
MEANTIME...PRECIPITATION ASSOCIATED WITH WA SHORTWAVE CONTINUES TO
FALL OVER MUCH OF THE PALOUSE...CENTRAL ID MOUNTAINS...AND
SPOKANE/COE AREAS. SUBSEQUENTLY WILL CONTINUE WITH THE SNOW
ADVISORIES FOR THOSE AREAS...ALTHOUGH SUSPECT THE ADDITIONAL
ACCUMULATIONS WILL BE LESS THAN AN INCH IN MOST LOCATIONS. THE SNOW
SHOULD BE DONE IN MOST AREAS BY MIDDAY. THE EXCEPTIONS WOULD BE OVER
THE CAMAS PRAIRIE...SOUTHERN SHOSHONE COUNTY...AND THE BLUES DUE TO
UPSLOPE FLOW COMBINED WITH DECENT LAPSE RATES AND MOISTURE FROM 850-
500MBS. AFTER THIS WE ARE IN FOR A PROLONGED DRY SPELL AS RIDGE
BECOMES THE DOMINANT FACTOR OVER THE PAC NW. THE MAIN PROBLEM TONIGHT
WILL BE IF THE DRYING ASSOCIATED WITH NORTHERLY FLOW WILL BE ENOUGH
TO SCOUR OUT THE LOW CLOUDS. THIS IS NOT CERTAIN...AS IT BEEN A VERY
DIFFICULT THING TO DO AS OF LATE. HOWEVER ITS HARD TO ARGUE WITH THE
MASSIVE DRYING FOUND ABOVE 850 MBS AND THE STRONG SUBSIDENCE BELOW.
SUBSEQUENTLY WILL GO WITH THE GRADUAL CLEARING AND WILL LOWER MIN
TEMPS FOR TONIGHT ACCORDINGLY. IF THINGS DO CLEAR...RADIATIONAL FOG
POTENTIAL LOOKS GOOD FOR LATE. MONDAY LOOKS PC FOR MOST AREAS...ASIDE
FROM THE FOG SHROUDED VALLEYS.

.EXTENDED...PROGS CONTINUE WITH BUILDING RIDGE OVER THE PACIFIC
NORTHWEST.  THIS RIDGE WILL DOMINATE UNTIL THE NEXT TROUGH APPROACH
THE WEST COAST LATE FRIDAY.  WEATHER FROM THE APPROACHING TROUGH WILL
NOT REACH EASTERN WASHINGTON OR THE PANHANDLE UNTIL SATURDAY SO WILL
GO WITH A DRY FORECAST THROUGH FRIDAY.  WITH THE RIDGE AND HIGH
PRESSURE OVER THE AREA EXPECT WIDESPREAD FOG AND LOW CLOUDS TO BE
PREVALENT INTO FRIDAY. LH

...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS
IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND
FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS...

GEG 032/017/029 6-0
CQV 035/015/032 310
SPT 034/016/030 310
COE 034/020/030 7-0
WWP 031/020/029 821
LWS 036/027/033 620
PUW 035/022/032 810
EAT 035/020/030 000
MWH 037/021/030 100

.GEG...SNOW ADVISORY THIS MORNING WA ZONE 31
    ...SNOW ADVISORY THROUGH 6AM FOR THE SPOKANE AND CDA
       AREAS...
    ...SNOW ADVISORY THROUGH 9MAM FOR THE PALOUSE...