Severe Thunderstorm Warning 46, NWS Glasgow, MT

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
250 PM MDT WED JUL 16 2003

.SHORT TERM...
UPPER RIDGE CONTINUES TO BUILD WITH UPPER TROF SLOWLY ROTATING
THROUGH SOUTHERN BC. MONSOONAL MOISTURE FINALLY MAKING AN APPEARANCE
OVER DESERT SOUTHWEST AND AS RIDGE AMPLIFIES WILL REACH INTO MONTANA
BY THURSDAY. WEAK SHORTWAVES IN THE SOUTHWEST FLOW EXPECTED TO
TRIGGER THUNDERSTORMS ACROSS MONTANA THIS AFTERNOON AND EVENING.
INITIAL STORMS EXPECTED TO BE DRY WITH MODIFIED INVERTED-V
SOUNDINGS. MAIN CONCERN FOR THUNDERSTORM DEVELOPMENT IS THAT AIRMASS
VERY WARM AND MODEL SOUNDINGS SUGGEST STRONG CAP OVER EASTERN
MONTANA FOR MOST OF THE DAY. EVEN THOUGH AIRMASS BECOMES
INCREASINGLY UNSTABLE...MAY NOT BE ENOUGH TO OVERCOME CAP. DECENT
LOW LEVEL SOUTHEAST JET PUSHES INTO EASTERN MONTANA THIS AFTERNOON
FOR RISING DEWPOINTS OVER EASTERN ZONES. THIS WILL HELP ESTABLISH
DRY LINE FRONT OVER CENTRAL MONTANA AND A FOCUS FOR CONVECTIVE
DEVELOPMENT. THUS WILL KEEP THE LOW POPS FOR DRY THUNDERSTORMS THIS
AFTERNOON AND EVENING. WILL UPGRADE FIRE WEATHER WATCH TO RED FLAG
WARNING MAINLY FOR INCREASE IN THUNDERSTORM POTENTIAL AFTER
PROLONGED DRY PERIOD.

THUNDERSTORMS TRANSITION TO WET LATE TONIGHT AS PRECIPITABLE WATER
INCREASES TO OVER AN INCH ACROSS THE CWA. DEW POINTS ALSO RISE TO
NEAR 60 OVER EASTERN ZONES. FRONT ALSO WORKS ITS WAY ACROSS THE CWA
ON THURSDAY WITH UPPER TROF MOVING INTO CENTRAL CANADA. HOWEVER
EXPECT ONLY SLIGHT COOLING WITH FLATTENING OF THERMAL RIDGE.

FRONT MOVES INTO DAKOTAS ON FRIDAY WITH DRY HIGH PRESSURE BUILDING
BACK INTO STATE. UPPER RIDGE REBOUNDS TO THE WEST FOR AGAIN SLIGHTLY
COOLER TEMPERATURES OVER NORTHEAST MONTANA. EBERT

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...
A LARGE RIDGE OF HIGH PRESSURE COVERS MUCH OF THE WESTERN CONUS
THROUGH EARLY NEXT WEEK. 500H HEIGHTS WILL APPROACH 600 DAM AT
TIMES IN THE VICINITY OF THE FOUR CORNERS WHICH IS COMMON FOR
MID-JULY. 500H HEIGHTS ARE PROGGED TO CLIMB INTO THE 580S AND LOW
590S AS FAR NORTH AS EASTERN MT SO TEMPERATURES WILL AVERAGE ABOVE
NORMAL WITH HIGHS WELL INTO THE 90S MOST DAYS WITH ISOLATED TRIPLE
DIGIT READINGS POSSIBLE. THE NEXT SIGNIFICANT SHORT WAVE TO PUSH
THROUGH THE RIDGE SATURDAY EVENING. PER COORDINATION WITH
SURROUNDING OFFICES WILL ADD IN A CHANCE OF THUNDERSTORMS FOR THIS
FEATURE ACROSS OUR EASTERN ZONES. OUR UPPER FLOW WILL AT LEAST
BRIEFLY TURN INTO THE NW BEHIND THIS FEATURE SUNDAY. HEIGHTS AND
THICKNESSES SUPPORT COOLER TEMPS FOR A DAY. THE UPPER RIDGE REBOUNDS
AGAIN EARLY NEXT WEEK FOR DRY AND HOT WEATHER WITH HIGHS IN THE 90S.
CB

KGGW BEU /097 064/096 056/088 9023330
     BBBB 057/091 057/087 057/088 056/094 056/ 92000000000
KGDV BEU /098 065/098 057/089 9023330
     TBBB 057/090 057/086 056/086 056/095 056/ 92033000000

.GGW...RED FLAG WARNING THIS AFTERNOON AND EVENING FOR FIRE WEATHER
ZONES 119>122.

MTZ016>027-059>062-171200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
215 PM MDT WED JUL 16 2003

.DAY ONE...

A RED FLAG WARNING IS IN EFFECT FOR THIS AFTERNOON AND EVENING.
REFER TO GTFRFWGGW OR WWUS85 KGGW FOR FURTHER DETAILS.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...

THE THREAT OF SEVERE THUNDERSTORMS EXISTS ON THURSDAY AFTERNOON
AND EVENING. STRONG WINDS ARE POSSIBLE WITH ANY THUNDERSTORMS THAT
DEVELOP.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

LYNN