Severe Thunderstorm Warning 29, NWS Billings, MT

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
900 PM MDT SUN JUN 10 2001

.MON AND TUE...
CONVECTION HAS YET TO GET GOING...BUT STILL HOLDING OUT THE CHANCE OF
DEVELOPMENT. WHAT CONVECTION THERE HAS BEEN THIS EVENING...HAS BEEN
NORTH. THIS HAS SENT OUTFLOW BOUNDARIES THROUGH SOUTH CENTRAL MONTANA
AND KNOCKED THE EDGE OFF THE INSTABILITY. AT THE SAME TIME...SURFACE
COLD FRONT HAD EASED INTO SOUTHWEST AND SOUTH CENTRAL MONTANA. THE FRONT
FLIRTING WITH THE SOUTHEAST...WHICH IS THE MOST UNSTABLE. MAIN MID LEVEL
COOLING WEST OF THE AREA...AND AS HEIGHTS LOWER...THIS WILL ADVANCE EAST
AND ALLOW CAPPING TO ERODE FURTHER. SECONDLY...A SHORTWAVE WAS MOVING UP
FROM NORTHEAST IDAHO THAT THE NEW ETA DID NOT HANDLE WELL AT ALL.
EXTRACTING THIS OUT...WILL TAKE IT OVER THE AREA TONIGHT. THIS COMBINED
WITH MID LEVEL COOLING WOULD LEAD TO SCATTERED SHOWERS AND T-STORMS.
WILL KEEP THE MENTION OF SEVERE IN THE SOUTHEAST WHERE THE BEST
INSTABILITY LAYS...BUT REMOVE IT FROM SOUTH CENTRAL MONTANA. POPS STILL
LOOK GOOD. WILL TAKE A LOOK AT WINDS WHILE I AM AT IT. HUMPHREY

.WED...THU...FRI...SAT...SUN...
EXPECT WET WEATHER EARLY AND MAINLY BELOW NORMAL TEMPERATURES THROUGHOUT
THE EXTENDED. THERE IS SIMILITUDE IN THE MEDIUM RANGE MODEL FORECASTS.
AN UPPER LOW WILL TRAVERSE THE ROCKIES WEDNESDAY AND THURSDAY. THIS WILL
PRODUCE A HIGH PROBABILITY OF RAIN OVER THE AREA WEDNESDAY. NORTHEAST
FACING SLOPES STAND TO GET THE MOST PRECIPITATION. THOSE WHO HAVE PLANS
TO VISIT YELLOWSTONE PARK DURING THE MIDDLE OF THE WEEK (VIA BEARTOOTH
PASS AND EAST ENTRANCE ESPECIALLY) CAN EXPECT SNOW. 700MB TEMPERATURES
ARE FORECAST TO COOL AS LOW AS -5C TO -7C WEDNESDAY UNDER THE COLD UPPER
CORE PASSING OVER YELLOWSTONE AND GRAND TETON PARKS. THE CENTER OF THE
UPPER LOW EJECTS FROM WYOMING LATE WEDNESDAY AND IS ACROSS THE DAKOTAS
THURSDAY. THIS PLACES SOUTHERN MONTANA UNDER OPTIMUM UPWARD VERTICAL
MOTION. TO BLEND IN WITH THE SHORT TERM FORECASTER...WILL GO LIKELY
PROBABILITIES WEDNESDAY THEN LOWER THEREAFTER AS THE FLOW BECOMES WEAK
CYCLONIC. AN OPEN SHORTWAVE PASSES FROM WASHINGTON TO NORTHERN MONTANA
FRIDAY AND SATURDAY. OFTEN WHEN MOST ENERGY PASSES TO OUR NORTH LIKE
THIS...OUR CHANCES FOR SHOWERS ARE MINIMAL. R CANEPA

    MON     TUE     WED     THU     FRI     SAT     SUN
-----------------------------------------------------------
BIL 052/072 048/065 044/053 042/063 046/070 048/073 047/075
    43/T    46/T    77/R    43/W    22/B    22/B    22/B
LVM 046/070 042/059 035/046 037/058 044/070 046/073 048/074
    33/T    46/T    77/O    43/W    22/B    22/B    22/B
HDN 048/073 045/066 041/054 040/064 044/072 046/075 048/078
    43/T    46/T    77/R    43/W    22/B    22/B    22/B
MLS 055/074 050/069 045/057 044/066 046/074 049/077 049/078
    42/T    46/T    44/W    43/W    22/B    22/B    22/B
4BQ 055/074 048/070 044/056 043/065 045/073 048/076 048/078
    42/T    46/T    44/W    43/W    22/B    22/B    22/B
BHK 053/074 047/071 043/058 042/064 044/072 047/075 047/077
    42/T    46/T    44/W    43/W    22/B    22/B    22/B
SHR 052/073 047/072 042/055 040/063 042/070 044/073 045/075
    32/T    46/T    77/R    43/W    22/B    22/B    22/B