000 
FXUS65 KBYZ 012109
AFDBIL

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
210 PM MST THU FEB 01 2001

.FRI AND SAT...

LEE TROF WILL BE IN PLACE OVER THE AREA TONIGHT...BRINGING WINDY
CONDITIONS TO THE UPPER YELLOWSTONE VALLEY.  SHORTWAVE RESPONSIBLE FOR
THE TROF WILL EXIT THE REGION THIS EVENING...SO LEE TROF WILL WEAKEN
AND MOVE INTO THE DAKOTAS. STRONG PRESSURE GRADIENTS WILL REMAIN ACROSS
THE UPPER YELLOWSTONE VALLEY BECAUSE OF A BUILDING HIGH PRESSURE AREA
IN THE GREAT BASIN.  THE LEE TROF WILL REDEVELOP ACROSS CENTRAL
MONTANA FRIDAY AHEAD OF A STRONGER PACIFIC SYSTEM. JET STREAK
ASSOCIATED WITH THE SYSTEM HAS A FAVORABLE VERTICAL CIRCULATION FOR
TIGHTENING THE PRESSURE GRADIENTS ACROSS THE UPPER YELLOWSTONE VALLEY.
WITH TIGHTENING PRESSURE GRADIENTS AND 700 MB WINDS GREATER THAN 40
KNOTS...WILL ISSUE A HIGH WIND WARNING FOR THE UPPER YELLOWSTONE VALLEY.
INVERSION TRAPPING MOUNTAIN WAVES WILL DISSIPATE AROUND 20Z FRIDAY...
CAUSING WINDS ACROSS THE UPPER YELLOWSTONE VALLEY TO DECREASE. A WEAK
PACIFIC COLD FRONT IS ASSOCIATED WITH THIS SYSTEM AND WILL MOVE ACROSS
THE FORECAST AREA FRIDAY NIGHT. I WILL KEEP THE MENTION OF ISOLATED
SHOWERS IN THE FORECAST FOR THIS FRONTAL SYSTEM.  STRONG WEST TO
NORTHWEST WINDS WILL DEVELOP BEHIND THE FRONT OVER SOUTH CENTRAL AND
SOUTHERN CENTRAL MONTANA. MIDDENDORF

.SUN...MON...TUE...WED...THU...

RIDGE IS FORECAST TO BUILD INTO THE PACNW ON SUNDAY AND PROGRESS EAST
INTO THE AREA BY TUESDAY.  A MINOR RIPPLE MAY HEAD DOWN IN NORTHWEST
FLOW ON SUNDAY. BUT IT WILL PROBABLY BE QUITE WEAK...SO WILL KEEP THE
DRY FORECASTING GOING. AFTER TUESDAY ANOTHER SHORT WAVE TROUGH WILL
HEAD INLAND AND INTO THE ROCKIES FOR WEDNESDAY.  A SERIES OF
SHORT WAVES WILL FOLLOW THAT INITIAL SHORT WAVE AND CARVE OUT A LARGE
SCALE TROUGH OVER THE ROCKIES. THERE MAY BE SOME LIGHT SHOWERS OVER THE
AREA ON WEDNESDAY...BUT FOR NOW WILL KEEP DRY FORECAST GOING.  BUT
WILL INTRODUCE SHOWERS FOR THURSDAY. MOORE

    FRI     SAT     SUN     MON     TUE     WED     THU
-----------------------------------------------------------
BIL 025/044 022/035 022/037 025/040 024/036 025/038 017/033
    00/E    20/B    11/B    11/B    22/E    22/E    33/J
LVM 028/045 020/033 020/038 023/039 022/035 024/039 020/036
    02/N    22/B    11/B    11/B    22/E    22/E    33/J
HDN 020/045 018/036 020/035 023/042 022/037 023/036 019/032
    00/E    20/B    11/B    11/B    22/E    22/B    33/J
MLS 018/037 025/035 018/035 020/038 020/033 020/036 012/030
    00/E    20/N    11/B    11/B    22/E    22/E    33/J
4BQ 019/037 023/033 016/033 019/035 019/031 018/034 015/031
    00/E    20/N    11/B    11/B    22/E    22/E    33/J
BHK 016/035 019/030 015/030 017/033 017/029 016/032 012/028
    00/E    20/N    11/B    11/B    22/E    22/E    33/J
SHR 018/043 025/036 017/034 020/038 020/033 020/039 013/030
    00/E    20/B    11/B    11/B    22/E    22/B    33/J