High Wind in Oregon, December 1, 2001

SOUTHWEST IDAHO/SOUTHEAST OREGON AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE IDAHO
915 PM MST SAT DEC 01 2001

...UPDATED ZONES TO REMOVE SNOW ADVISORY AND ADJUST OVERNIGHT
WORDING...BROAD UPPER LEVEL TROUGH FROM EASTERN PACIFIC ACROSS
PACIFIC NORTHWEST WITH SERIES OF S/WV TROUGH ROTATING THROUGH COMMON
TROUGH. 1ST S/WV SOUTHWEST BC TO SOUTH CENTRAL ORE AT 00Z LIFTING
NORTHEAST ACROSS CWFA BY 03Z. MAIN DYNAMICS/MOISTURE EAST OF CWFA AS
OF 03Z WITH KCBX RADAR SHOWING JUST SCATTERED RAIN/SNOW SHOWERS
SOUTHWEST ID ZONES AND SOME CLEARING IN SOUTHEAST ORE ZONES. WITH
MODERATE WEST SOUTHWESTERLY FLOW ALOFT PRODUCING SOME OROGRAPHIC
LIFT EXPECT SCATTERED MOUNTAIN SNOW SHOWERS TO CONTINUE SOUTHWEST ID
ZONES UNTIL AFTER MIDNIGHT NIGHT. A LITTLE BETTER DYNAMICS NORTHWEST
ORE/WESTERN WA WITH WRAP-AROUND MOISTURE CLOSER TO UPPER LOW CENTER.
HOWEVER THIS FEATURE LIFTING NORTHEAST INTO SOUTHWEST CANADA WITH
ASSOCIATED SHOWERS REMAINING NORTH OF CWFA LATER TONIGHT.

STRONGER 2ND S/WV AROUND 39N/135W AT 03Z REACHES NORTHERN CA COAST
BY 12Z SUN WITH ASSOCIATED SURFACE COLD FRONT CRESTING CA SIERRA.
STATIONARY FRONT ACROSS SOUTHERN ID BEGINS LIFTING NORTH AS A WARM
FRONT SUN MORNING AS AN UPPER LEVEL SOUTHWESTERLY JET CORE CROSSES
CENTRAL CA INTO NORTHWEST NV. THIS JET DYNAMICS ALONG WITH WARM
OVER-RUNNING MOISTURE PRODUCES NEXT WIDESPREAD RAIN/SNOW IN CWFA.
VALLEYS TO SEE EARLY MORNING SNOW BEFORE CHANGING TO RAIN BY
AFTERNOON AS WARM FRONT LIFTS NORTH. AGAIN FAVORABLE SOUTHWESTERLY
FLOW FOR GOOD OROGRAPHIC LIFT TO KEEP MOUNTAIN SNOW CONTINUING INTO
SUN NIGHT. MID SHIFT MAY NEED WINTER STORM WATCH/HEAVY SNOW WARNING
FOR NORTHERN ZONES LATER SUN/SUN NIGHT. S/WV SWINGS NORTHEAST OUT OF
PARENT TROUGH NEAR NORTHERN CA COAST SUN NIGHT FORCING SURFACE COLD
FRONT ACROSS CWFA FOR SNOW LEVEL LOWERING TO LOWEST VALLEYS.
UNSETTLED WEATHER PATTERN CONTINUES MON WITH RESIDUAL SNOW SHOWERS.
PARKER

.BOI...NONE.