High Wind in Montana, November 16, 2002

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
155 PM MST SAT NOV 16 2002

.SHORT TERM...VALID FOR SUN AND MON...

WIND CONTINUES TO BE MAIN FORECAST ISSUE FOR THIS PACKAGE AGAIN AND
LOOKS TO BE A THAT WAY THROUGH TUESDAY.

TONIGHT...UPPER RIDGE GETS CRASHED AS UPPER ENERGY MOVES ACROSS THE
AREA. PRESSURE GRADIENT WILL BE MODERATE ALL NIGHT WESTERN ZONES FOR
WINDY CONDITIONS...WITH COLD COLD AIR ADVECTION AT LOW LEVELS WESTERN
ZONES EARLY...INTO EAST LATE TONIGHT. GRADIENT DOESNT INCREASE UNTIL
LATE EASTERN ZONES. AIRMASS WILL DESTABILIZE...LESSENING GAP EFFECT IN
LVM THROUGH THE NIGHT...ALTHOUGH PRESSURE GRADIENT WILL CONTINUE STRONG
THERE AND WILL KEEP HIGH WIND GOING THROUGH THE NIGHT. LOOKS CONTINUED
DRY.

SUNDAY...PRESSURE GRADIENT WILL RELAX THROUGH THE DAY...BUT GOOD
MIXING WITH SOME INSTABILITY AND FAST MID/UPPER FLOW WILL BE OVER
AREA...FOR WINDY CONDITIONS BUT PLAINS SHOULD REMAIN BELOW HIGH WIND
CRITERIA. IN EAST...800-850 MB WINDS RANGING FROM 40-45 KNOTS...BUT
WEAK UPWARD MOTION FORECASTED AND VERY LITTLE PRESSURE RISES THERE
THROUGH THE DAY...SO WILL CONTINUE TO FORECAST WINDS RIGHT UP TO
HIGHLIGHTS. IN WESTERN PLAINS...700 MB WINDS AROUND 40 KNOTS...SO WILL
GO WITH SAME WORDING THERE...DECREASING SOUTH INTO SHERIDAN. SOME
MOISTURE WORKS INTO LVM AREA AND WILL KEEP ISOLATED POPS GOING THERE.
TEMPERATURE RIDGE SHIFTS ACROSS AREA BUT NOT UNTIL LATER IN THE EAST...
SO WITH GOOD MIXING WILL UP TEMPERATURES THERE A BIT.

ANOTHER WAVE APPROACHES AGAIN. PRESSURE GRADIENT BEGINS INCREASING
AGAIN...EVEN INTO EASTERN ZONES...ALTHOUGH NOT AS STRONG. THICKNESSES
RISE OVERNIGHT FOR ANOTHER MILD NIGHT...AND WILL RAISE TEMPERATURES
CONSIDERABLY OVER WESTERN ZONES.

MONDAY...NORTHWEST FLOW OVER AREA AGAIN...WITH MODERATE SURFACE PRESSURE
GRADIENT. PRE-MENTIONED WAVE MOVES ACROSS THE AREA. WILL UP WINDS TO
GUSTING TO NEAR 50 MPH LVM AND BRIDGER GAP AREA. INVERSIONS SHOULD LIMIT
TEMPERATURES FROM GETTING TOO WARM AND WILL ONLY TWEAK CURRENT NUMBERS.
WILL KEEP EASTERN ZONES BELOW WINDY WORDING AT 15 TO 25 WITH WINDY
WORDING ELSEWHERE. SOME MOISTURE MAY SNEAK IN LVM AREA AND WILL GO WITH
ISOLATED POPS THERE AND IN THE MOUNTAINS.

PATTERN CHANGES VERY LITTLE INTO MONDAY NIGHT...WITH UPPER RIDGE NOSING
A BIT MORE INTO AREA FOR ANOTHER BREEZY/WINDY NIGHT IN WESTERN ZONES
WITH MILD OVERNIGHT TEMPERATURES. RASCH

.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
UPPER RIDGE BEGINS TO BUILD INTO MONTANA AGAIN ON TUESDAY. WARM
ADVECTION AHEAD OF THIS FEATURE SHOULD RESULT IN LARGE AREA OF CLOUD
COVER OVER MUCH OF MONTANA. TEMPS BEGIN TO WARM AS WELL...BUT WILL STAY
ONLY A FEW DEGREES ABOVE MONDAY WITH CLOUD COVER AND STABILIZING
ATMOSPHERE LIMITING MIXING. MAIN FORECAST CONCERN FOR TUESDAY WILL BE
WINDS...ESPECIALLY IN UPPER YELLOWSTONE VALLEY. STABILIZING ATMOSPHERE
AND CONTINUING GRADIENT WILL RESULT IN CONTINUED FLOW THROUGH
LIVINGSTON GAP. ONLY DIFFERENCE FROM TODAYS SCENARIO IS LACK OF STRONG
PRESSURE FALLS IN PLAINS...SO DO NOT EXPECT HIGH WIND CRITERIA AT THIS
TIME. WILL EXPAND WINDY WORDING ACROSS ENTIRE CWA WITH STRONG PRESSURE
GRADIENT AND STRONG WINDS ALOFT TUESDAY AND TUESDAY NIGHT.

UPPER RIDGE BUILDS OVER MONTANA WEDNESDAY AND THURSDAY ALLOWING FOR
TEMPORARY REPRIEVE TO WINDY CONDITIONS AS SYSTEMS PUSHED NORTHWARD
INTO CANADA ALONG WITH WARMING TREND TO AROUND 60. ENSEMBLES IN GENERAL
AGREEMENT THAT SYSTEM WILL BREAK DOWN RIDGE ON FRIDAY WITH RETURN OF
NORTHWEST FLOW AND COOLER TEMPERATURES. LAST COUPLE OF RUNS OF GFS
SENDING VERY STRONG COLD FRONT THROUGH ON FRIDAY WITH 850MB TEMPS
AROUND -16C IN EAST ON SATURDAY. WILL NOT TOTALLY BUY INTO GFS SOLUTION
YET...BUT WILL CONTINUE WITH COOLING TREND INTO LOW 40S BY SATURDAY.
WITH FRONTAL PASSAGE FRIDAY WILL ONCE AGAIN MENTION WINDY WORDING ALL
AREAS. WITH PROGRESSIVE NATURE OF FLOW WILL NOT MENTION POPS WITH
WEEKEND SYSTEM QUITE YET...BUT WILL CONTINUE WITH MOSTLY CLOUDY SKIES.
JZ

    SUN     MON     TUE     WED     THU     FRI     SAT
-----------------------------------------------------------
BIL 042/054 036/054 036/056 037/060 036/059 035/049 025/044
    00/N    00/N    00/N    00/B    00/B    00/N    00/E
LVM 044/050 038/052 038/055 034/057 036/057 035/047 024/044
    02/W    02/W    00/N    00/B    00/B    00/N    00/E
HDN 040/056 034/056 033/057 035/061 034/061 034/050 026/043
    00/N    00/B    00/N    00/B    00/B    00/N    00/E
MLS 034/059 032/053 032/055 035/060 036/060 034/047 024/042
    00/N    00/B    00/N    00/B    00/B    00/N    00/E
4BQ 033/060 030/055 031/055 034/059 035/061 034/047 023/042
    00/N    00/B    00/N    00/B    00/B    00/N    00/E
BHK 030/056 029/049 030/053 032/056 033/058 032/046 022/041
    00/N    00/B    00/N    00/E    00/B    00/N    00/E
SHR 030/054 025/048 029/055 033/060 032/059 034/046 023/042
    00/E    00/B    00/E    00/B    00/B    00/E    00/E

.BYZ...
MT...HIGH WIND WARNING FOR TONIGHT THROUGH SUNDAY MORNING FOR
ZONE MTZ040.

WY...NONE.

MTZ028>042-056>058-WYZ098-099-171200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BILLINGS MT
115 PM MST SAT NOV 16 2002

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL...SOUTHEAST
MONTANA AND NORTH CENTRAL WYOMING.

.DAY ONE...
STRONG WINDS WILL CONTINUE OVER THE UPPER YELLOWSTONE VALLEY TODAY.
REFER TO GTFNPWBYZ FOR MORE INFORMATION.

.DAY TWO THROUGH SEVEN...
STRONG WINDS WILL CONTINUE OVER THE UPPER YELLOWSTONE VALLEY THROUGH
SUNDAY. REFER TO GTFNPWBYZ FOR MORE INFORMATION.

.SPOTTER INFORMATION STATEMENT...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

WCJIN-WYNW-WYNE

JZ