Severe Thunderstorm Warning 20, NWS Billings, MT

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
135 PM MDT SUN JUN 22 2003

.SHORT TERM...VALID FOR MON AND TUE...
SEVERE THUNDERSTORM WATCH ISSUED FOR SOUTHEAST MT FROM ROSEBUD COUNTY
EAST TIL 800 PM. PRIMARY THREAT WITH THESE STORMS IS HAIL WITH LOWERED
FREEZING LEVELS.

STORMS SHOULD END FAIRLY EARLY IN THE EVENING. WILL KEEP ISOLATED POPS
GOING THROUGH EARLY EVENING ACROSS FORECAST AREA. ETA/GFS SIMILAR
EXCEPT AVN MUCH MORE GENEROUS WITH QPF. NEXT SYSTEM WILL BRING ANOTHER
ROUND OF THUNDERSTORMS MONDAY AFTERNOON AND EVENING. ETA NOT AS
UNSTABLE. UPPER TROUGH APPROACHES ZONES MONDAY NIGHT THROUGH TUESDAY
NIGHT. AREA IN GOOD DEFORMATION NORTH OF LOW. AIRMASS LOOKS COOL AND
STABLE...SO PRECIP ACTIVITY WILL BE MOSTLY THUNDERSTORM FREE...WITH
HIGHEST POPS IN THE SOUTHERN PORTION OF FORECAST AREA. SCARLETT

.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
GFS AND EXTENDED ETA CONTINUE TO SHOW DIFFERENCES IN HOW FAST UPPER LOW
MOVES AWAY FROM THE AREA WEDNESDAY INTO THURSDAY. ETA MUCH FASTER IN
DRYING OUT THE AREA AND GFS BEGINNING TO FALL A LITTLE MORE IN LINE WITH
THIS SOLUTION. SOME LINGERING WAVE ENERGY HANGS ON IN THE SOUTHEASTERN
ZONES INTO EARLY THURSDAY...BUT THE LOWER LEVELS SHOWING SUBSIDENCE AND
SUFFICIENT DRYING. WITH MAIN SYSTEM DYNAMICS TRENDING TO BE FURTHER OFF
TO THE EAST HAVE DECIDED TO DRY THURSDAY OUT WITH THIS FORECAST. BEYOND
THURSDAY MADE NO CHANGES TO THE GOING FORECAST AS THE EXTENDED MODELS
CONTINUE TO SHOW DIFFERENCES IN HANDLING UPPER TROUGH LATE IN THE
PERIOD. MACZKO

    MON     TUE     WED     THU     FRI     SAT     SUN
-----------------------------------------------------------
BIL 045/071 049/058 045/062 049/072 051/076 051/080 054/082
    33/T    36/W    63/T    00/B    00/B    00/B    00/B
LVM 035/064 042/056 038/064 044/070 046/074 049/078 050/080
    34/T    46/W    63/T    00/B    00/B    00/B    00/B
HDN 044/074 050/058 046/062 050/072 052/076 052/080 055/082
    33/T    46/W    63/T    00/B    00/B    00/B    00/B
MLS 049/074 049/066 045/068 050/074 052/077 052/081 055/083
    40/B    44/W    43/T    00/B    00/U    00/B    00/B
4BQ 050/072 049/064 045/066 049/073 050/077 050/081 053/083
    43/T    46/W    64/T    30/B    00/U    00/B    00/B
BHK 048/073 047/066 043/068 048/073 050/075 050/079 053/081
    40/E    44/W    43/T    00/B    00/U    00/B    00/B
SHR 042/067 048/056 044/058 046/068 048/075 048/079 051/081
    43/T    46/W    64/T    00/B    00/U    00/B    00/B

.BYZ...
MT...SEVERE THUNDERSTORM WATCH UNTIL 800 PM MDT SUNDAY FOR
ZONES MTC011...MTC017...MTC025...MTC075...MTC087.

WY...SEVERE THUNDERSTORM WATCH UNTIL 800 PM MDT SUNDAY FOR ZONE
WYC033.

MTZ028>042-056>058-WYZ098-099-231930-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BILLINGS MT
133 PM MDT SUN JUN 22 2003

.DAY ONE...
A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 8PM FOR PORTIONS OF
SOUTHEAST MONTANA AND NORTHERN WYOMING. GUSTY WINDS OF UP TO 60 MPH
AND LARGE HAIL ARE POSSIBLE WITH ANY STORMS THAT MAY DEVELOP THIS
AFTERNOON AND EVENING.

.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.