Severe Thunderstorm Warning 49, NWS Glasgow, MT

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
230 PM MDT SAT JUL 19 2003

.SHORT TERM...TONIGHT THROUGH MONDAY
BIGGEST FORECAST PROBLEM WILL BE WHAT HAPPENS WITH THE THUNDERSTORMS
OVER THE SE ZONES THIS EVENING. SHORTWAVE ENERGY IN A VEERING UPPER
FLOW HAS HELPED TO GENERATED HIGH-BASED STORMS OVER FAR EAST-CENTRAL
MT THIS AFTERNOON. MESO-ETA SEEMS TO HAVE A GOOD HANDLE ON THE DYNAMICS
AND INSTABILITY WITH THESE STORMS AND TRACK THEM EAST AND SOUTH THIS
EVENING...EXPECTING THEM TO OUT OF THE CWA BY 9PM.

OTHERWISE...SEMI-PERMANENT UPPER RIDGE OVER THE WESTERN STATES
BUILDS TO OUR WEST THE NEXT COUPLE OF DAYS AS A TROF OVER THE EASTERN
STATES SHARPENS. THIS WILL PUT THE CWA IN A NW FLOW AND PUSH A SURFACE
LOW CURRENTLY OVER SE MT INTO E SD TOMORROW. A SURFACE HIGH OVER SASK
SHOULD PUSH INTO THE DAKOTAS WITH COOLER AIR WORKING IN ON THE LOWER
LEVELS INTO AT LEAST THE NE ZONES FOR SUNDAY.

FOR MONDAY...THE ETA AND GFS CONTINUE TO DISAGREE WITH SOME UPPER
LEVEL ENERGY AND MOISTURE THAT MOVES SE INTO THE AREA ON THE NW FLOW.
THE AVN KEEPS THIS AREA WELL TO OUR NE WHILE THE ETA MOVES THIS INTO
NE MT AND W ND. SOME LIFT AT THE LOWER LEVELS MAY BE AVAILABLE AS THERE
SHOULD BE A STATIONARY FRONT OVER EASTERN MT. WILL LEAVE FORECAST DRY...
BUT LATER SHIFTS WILL HAVE TO KEEP AN EYE ON THIS.  JAMBA

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
MEDIUM RANGE MODELS IN OKAY AGREEMENT TODAY. HIGH THAT RETROGRADES
TO GREAT BASIN EARLY IN THE PERIOD STAYS ANCHORED IN PLACE THROUGH
AT LEAST WEDNESDAY. TOP OF RIDGE NOSES INTO MONTANA WITH RATHER
DIRTY FLOW OVER THE TOP. GFS BRINGS STRONG WAVE THROUGH ON
WEDNESDAY...BUT BOTH CANADIAN AND ECMWF KEEP THIS ENERGY TO THE
WEST. FOR NOW...WILL LEAVE FORECAST DRY AND ALLOW ANOTHER MODEL RUN
OR TWO FOR BETTER CONSISTENCY. MAIN CHANGE TO MONDAY NIGHT THROUGH
WEDNESDAY WAS TO RAISE TEMPERATURES...ESPECIALLY LOWS. EVEN MODEST
MIXING SUPPORTS HIGH TEMPERATURES IN THE LOWER AND MID 90S..THUS
LOWS IN THE UPPER 50S AND LOWER 60S. MODEL DIFFERENCES EMERGE BY
THURSDAY. GFS SWINGS A FRONT ON THROUGH LATE THURSDAY WITH STRONG
UPPER LOW IN CANADA FLATTENING RIDGE. ECMWF SPLITS LOW WITH ENERGY
HANGING OFF THE COAST WHICH ALLOWS WARM AIR TO STAY IN PLACE AND
KEEPS RIDGE STRONGER. FORECAST ALREADY HAS GOOD TREND SO NO CHANGES
TO FRIDAY OR SATURDAY. STROOZAS

KGGW UBB 062/090 059/090 062/099 76000000
     BBTT 061/095 061/095 061/089 058/085 9600000333

KGDV UBB 064/091 058/086 062/095 76200000
     BBTT 060/098 063/096 062/094 059/090 9600000333

.GGW...NONE.

MTZ016>027-059>062-201200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
600 AM MDT SAT JUL 19 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MONTANA

.DAY ONE...

ISOLATED THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON AND EVENING
EAST OF A LINE FROM OPHEIM...TO GLASGOW...TO SOUTH OF JORDAN NEAR
THE GARFIELD COUNTY LINE. SOME STORMS COULD BE SEVERE WITH DAMAGING
WIND.

.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.