High Wind in Montana, January 26, 2003

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
859 AM MST SUN JAN 26 2003

.SHORT TERM...VALID FOR TDY AND MON...

MAIN PROBLEMS FOR UPDATE ARE WINDS...MIXED PRECIPITATION AND HIGHS.
NO UPDATE TO AFP OR ZFP.

AS NORMAL...MODELS A LITTLE TOO QUICK PULLING OUT ARCTIC TODAY...BUT IT
SHOULD HAPPEN IN WESTERN ZONES FOR SURE. CURRENTLY RED LODGE AND
LIVINGSTON ABOVE THE ARCTIC WITH TEMPERATURES AROUND 40. LVM HAS
VERIFIED HIGH WIND CRITERIA WITH SUSTAINED 2-MIN WIND OF 54 MPH WITH A
GUST TO 63 MPH AROUND 15Z...SO WILL KEEP THE HIGH WIND GOING AS IT
SHOULD ONLY GET WINDIER TODAY WITH INCREASING GRADIENT AND LOW/MID
LEVEL WINDS. ACARS DATA FOR BILLINGS SHOWING ARCTIC ABOUT 2000 FEET
DEEP WITH AREA ABOVE FREEZING NOT THAT BIG SO PRECIPITATION THIS MORNING
SHOULD BE FREEZING RAIN WITH ICE PELLET MIX MIX. RADAR SHOWING BAND OF
MOISTURE CURRENTLY WORKING SOUTH FROM WHEATLAND/GOLDEN VALLEY WITH SOME
BRIGHT BANDING SHOWING UP. THIS IS LIKELY ASSOCIATED WITH STRONG WARM
AIR ADVECTION WORKING ACROSS THE AREA. HAVENT BEEN ABLE TO GROUND TRUTH
THE RETURNS YET. AM CONCERNED THAT WINTER WEATHER ADVISORY FOR
FREEZING RAIN MAY BE NEEDED FURTHER WEST FOR THIS...BUT WITH MIX
FORECAST ALREADY COVERED IN ZONES AND SMALL AREAL COVERAGE OF IT...WILL
LEAVE ADVISORY ALONE. IN THE EAST...WARM AIR ADVECTION PRODUCING LIGHT
SNOW AT THIS TIME SO HIGH POPS LOOK GOOD THERE. ETA IS A BIT FURTHER
NORTH AND EAST WITH MAIN BATCH OF MOISTURE THIS AFTERNOON...BUT LOOKING
AT THINGS NOW..THIS MAY BE TOO FAR TO THE NORTH AND EAST AND WILL KEEP
CURRENT ADVISORY WHERE IT IS PLACED.

WINDS AND TEMPERATURES...ETA ALSO FORECASTING AREA OF 50 KNOTS WINDS AT
850 MB TO WORK INTO EASTERN ZONES AND 50 KNOTS AT 700 MB ACROSS
WESTERN ZONES BY LATE AFTERNOON. THIS SHOULD REALLY HELP TO SCOUR OUT
THE ARCTIC AIR. 700-500 MB LAPSE RATES ALSO PROGGED TO INCREASE TO
6.5C/KM BY LATE THIS AFTERNOON ACROSS THE AREA RAISING THE RISK OF
MIXING SOME OF THIS AIR DOWN...IN ADDITION TO MODERATE PRESSURE GRADIENT
IN WESTERN ZONES. BELIEVE INVERSION WILL REMAIN IN EASTERN ZONES ENOUGH
TO KEEP WINDS DOWN. IN THE WEST WITH BETTER MIXING...HIGH WINDS A
BIGGER THREAT. BELIEVE LAPSE RATES IN LOWER LEVEL WILL REMAIN LOW
ENOUGH TO PREVENT HIGHER WINDS FROM MIXING DOWN AND WILL KEEP WINDS
BELOW HIGH WIND...AT CURRENT FORECASTED LEVELS OF 20 TO 35 MPH GUST TO
45 MPH. RASCH

.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...

A WEAK WAVE PUSHES ACROSS THE AREA MONDAY NIGHT INDUCING NORTHWEST FLOW
AND REDUCING DOWNSLOPE WARMING RESULTING IN SOMEWHAT COOLER TEMPERATURES
ON TUESDAY. COLD FRONT BACKS INTO THE AREA LATE TUESDAY WITH GFS
HOLDING COLD AIR ACROSS EASTERN ZONES...GIVEN RECENT HISTORY OF THE GFS
HANDLING OF CANADIAN AIRMASSES WOULD EXPECT COLD AIR TO MAKE IT INTO ALL
OF THE CWA AS A SHALLOW LAYER OF ARCTIC AIR. HIGHS ON TUESDAY LOOK GOOD
AS COLDER AIR WILL NOT MAKE IT INTO THE AREA UNTIL LATE IN THE DAY. LOWS
TUESDAY LOOK OK IN THE EAST BUT IN THE WEST MAY HAVE TO ADJUST
TEMPERATURES DOWNWARD GIVEN POTENTIAL FOR COLD AIR TO PUSH FURTHER WEST.
WILL HOLD OFF ON MAKING THIS CHANGE UNTIL NEXT MODEL RUN TO SEE IF MODEL
TRENDS FURTHER WEST AND TO KEEP GOOD ALIGNMENT WITH SURROUNDING OFFICES.
WARM MOIST PACIFIC FLOW RETURNS ON WEDNESDAY TO PUSH COLD AIR OUT OF THE
AREA ONCE AGAIN. MAY BE SOME LIGHT PRECIPITATION ASSOCIATED WITH WAA
PATTERN BUT NOT ENOUGH TO INTRODUCE POPS AT THIS POINT. FAIRLY STRONG
WAVE TOPS PACIFIC RIDGE AND DROPS INTO THE AREA ON THURSDAY WITH LOWER
THICKNESSES AND A CHANCE OF SNOW ACROSS THE ENTIRE AREA. FOR FRIDAY
SHORTWAVE RIDGE MOVES OVER THE AREA...BUT THICKNESSES HOLD STEADY FOR
PARTLY CLOUDY AND COOL CONDITIONS. ANOTHER PACIFIC WAVE MOVES ACROSS THE
AREA SATURDAY FOR ANOTHER CHANCE OF SNOW SHOWERS. CHAMBERS

    TDY MON     TUE     WED     THU     FRI     SAT
-------------------------------------------------------
BIL 042 036/046 027/038 021/042 024/039 024/037 024/037
    3/O 00/E    00/E    00/B    03/J    30/B    03/J
LVM 049 038/050 025/040 022/043 022/039 022/037 022/035
    3/S 00/E    00/E    00/E    02/J    23/J    33/J
HDN 042 032/047 024/037 021/043 021/040 021/038 021/038
    4/O 00/E    00/B    00/B    03/J    30/B    03/J
MLS 032 022/043 019/031 012/036 017/033 017/031 017/032
    +/O 00/E    00/B    00/U    03/J    30/B    03/J
4BQ 032 024/047 022/038 016/038 016/035 016/033 016/033
    +/O 00/E    00/B    00/B    03/J    30/B    03/J
BHK 027 020/043 017/029 010/034 013/031 013/029 013/031
    +/O 00/E    00/B    00/U    03/J    30/B    02/J
SHR 047 027/047 022/037 020/040 020/037 020/035 020/037
    4/O 00/E    00/B    00/B    03/J    30/B    03/J

.BYZ...
MT...HIGH WIND WARNING FOR TODAY AND TONIGHT FOR ZONE MTZ040.

WINTER WEATHER ADVISORY FOR TODAY FOR ZONES MTZ030>033...MTZ036>037.

WY...NONE.

MTZ028>042-056>058-WYZ098-099-271145-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BILLINGS MT
454 AM MST SUN JAN 26 2003

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

.DAY ONE...
SNOW OVER SOUTHEAST MONTANA WILL CHANGE TO A MIX OF SNOW...SLEET AND
FREEZING RAIN THIS AFTERNOON. A WINTER WEATHER ADVISORY IS IN EFFECT
FOR SOUTHEAST MONTANA TODAY. REFER TO GTFWSWBYZ FOR DETAILS.

ALSO...SOUTHWEST WINDS OF 35 TO 50 MPH WITH OCCASIONAL GUSTS TO 65
MPH WILL OCCUR THROUGH TONIGHT OVER THE UPPER YELLOWSTONE VALLEY. A
HIGH WIND WARNING IS IN EFFECT FOR PARK COUNTY. REFER TO GTFNPWBYZ
FOR DETAILS.

.DAYS TWO THROUGH SEVEN...
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

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

WCJIN-WYNW-WYNE

ARTHUR