Severe Thunderstorm Warning 14, NWS Billings, MT

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
256 PM MDT SUN JUN 15 2003

...UPDATED FOR SEVERE THUNDERSTORM WATCH...

.SHORT TERM...VALID FOR MON AND TUE...

BAND OF CLOUDS AND PRECIPITATION HANGING ON OVER THE SW ZONES...ALTHOUGH
IT IS SLOWLY PUSHING NORTH. ASSOCIATED CLOUDS HAVE KEPT TEMPERATURES
FROM WARMING OVER WESTERN AND CENTRAL ZONES...BUT THE EAST IS WARMING
INTO MID 80S WITH DEWPOINTS IN THE UPPER 50S.  SURFACE TO 6KM SHEAR
STILL LOOKS TO BE SUFFICIENT FOR SUPERCELL DEVELOPMENT GIVEN THE
CAPE. POTENTIAL FOR SEVERE IS NOT AS HIGH FROM SHR-BIL AND POINTS WEST
DUE TO COOLER TEMPS.  HOWEVER...CLEARING COULD STILL TAKE PLACE AND
WITH THE LATE SUNSET...CONDITIONS COULD STILL GET UNSTABLE. BASED ON
AFFOREMENTIONED PARAMETERS...THE GREATEST THREAT OF SEVERE STORMS IS IN
THE EAST. EXPECT THE CURRENT COVERAGE TO SLOWLY DEVELOP NORTH AND EAST.
ANOTHER AREA OF CONVECTION SHOULD GET GOING ALONG A SURFACE TROUGH
EXTENDING FROM NEAR MLS TO GCC AND HEAD EAST TONIGHT. WILL CONTINUE HIGH
CHANCE POPS.

THE SURFACE HIGH BUILDS SOUTH IN THE NORTHEAST ZONES FOR TUESDAY WHICH
SHOULD CAP THOSE LOCATIONS.  SHEAR IS MUCH WEAKER MONDAY AS IS THE
INSTABILITY/FORCING.  WILL KEEP SOME MENTION OF PRECIP IN...BUT IT
DOESNT LOOK AS GOOD AS TONIGHT.  BEST SHOT MONDAY WILL BE THE SE WHERE
A SURFACE BOUNDARY MAY HELP FOCUS CONVECTION.

TEMPS CONTINUE AT OR ABOVE NORMAL THROUGH TUESDAY WITHOUT ANY BIG
CHANGES. MOORE

.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
STRONG UPPER RIDGE BUILDS OVER THE FORECAST AREA WEDNESDAY AND THURSDAY
WITH WARMING TEMPERATURES AND DRY WEATHER. MODELS CONTINUE TO SHOW A
HINT OF SOUTHWEST FLOW ALOFT OVER THE AREA...BUT ANY WEAK FORCING
SHOULD BE OVERCOME BY STRONG SUBSIDENCE THAT WILL BE PRESENT ALONG
WITH A STABLE AIR MASS. STRONG THERMAL RIDGE TO CREEP INTO THE WESTERN
ZONES WEDNESDAY...AND MOVE EAST ON THURSDAY. HAVE BUMPED A FEW TEMPS
IN THE WEST ON WED AND LEFT THURS ALONE FOR NOW...THOUGH WITH LATEST
GFS PROGGING 700MB TEMPS AT +12C AND GREATER OVER THE CENTRAL ZONES
THURSDAY TEMPS MAY HAVE TO BE RAISED A FEW DEGREES. SURFACE FRONT STILL
FORECAST TO PUSH ACROSS THE FORECAST AREA LATE THURSDAY INTO FRIDAY.
TIMING ISSUES STILL EVIDENT IN THE MODELS...BUT THE TREND TO SLOW
EASTWARD PROGRESSION OF FRONT CONTINUES. GFS NOW KEEPING FRONT OUT OF
EASTERN ZONES THROUGH EARLY FRIDAY...ALONG WITH ANY ASSOCIATED PRECIP.
IF THIS SOLUTION CONTINUES TO SHOW UP...POPS FOR THURSDAY NIGHT IN THE
EAST MAY HAVE TO BE REMOVED. UPPER TROUGH DIGS INTO THE WESTERN US
THURSDAY WITH SOUTHWEST FLOW RETURNING TO THE AREA FRIDAY AND
SATURDAY. GOING POPS THOSE DAYS STILL ON TRACK AND WILL NOT MAKE ANY
CHANGES THERE. UPPER TROUGH MOVES THROUGH LATE SATURDAY WITH ZONAL FLOW
TRAILING ON SUNDAY. MACZKO

    MON     TUE     WED     THU     FRI     SAT     SUN
-----------------------------------------------------------
BIL 057/082 053/081 053/083 057/085 057/081 054/077 054/078
    42/T    20/B    00/B    00/B    33/T    33/T    30/B
LVM 052/079 048/077 048/085 053/081 053/077 049/073 049/074
    43/T    30/U    00/B    00/B    33/T    33/T    30/B
HDN 058/082 053/082 053/084 056/086 056/082 055/078 055/079
    42/T    20/B    00/B    00/B    33/T    33/T    30/B
MLS 059/081 054/083 053/083 057/086 057/083 054/077 054/078
    40/U    00/U    00/B    00/B    33/T    33/T    30/B
4BQ 059/082 054/081 053/082 055/084 057/081 055/076 055/077
    43/T    30/U    00/B    00/B    33/T    33/T    30/B
BHK 059/080 051/083 054/084 058/085 058/083 055/075 055/076
    43/T    00/U    00/B    00/B    33/T    33/T    30/B
SHR 055/082 051/082 052/083 055/087 055/084 054/080 054/081
    42/T    20/U    00/B    00/B    33/T    33/T    30/B

.BYZ...
MT...SEVERE THUNDERSTORM (WCN) WATCH UNTIL 800 PM MDT SUNDAY FOR
ZONES MTC011...MTC017...MTC025...MTC075.

WY...NONE.

MTZ028>042-056>058-WYZ098-099-161245-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BILLINGS MT
243 PM MDT SUN JUN 15 2003

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

.DAY ONE...

THERE IS A CHANCE OF SEVERE THUNDERSTORMS EAST OF ROSEBUD COUNTY
THIS AFTERNOON. A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR
CUSTER...CARTER...POWDER RIVER...AND FALLON COUNTIES. LARGE HAIL AND
DAMAGING WINDS ARE POSSIBLE WITH ANY THUNDERSTORMS THAT DEVELOP THIS
EVENING.

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

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL BE REQUIRED THIS EVENING. SPOTTERS SHOULD
REPORT ANY SIGNIFICANT WEATHER TO LOCAL LAW ENFORCEMENT OR THE
NATIONAL WEATHER SERVICE ACCORDING TO STANDARD OPERATING
PROCEEDURES.