Severe Thunderstorm Warning 28, NWS Glasgow, MT

NORTHEAST MONTANA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
232 PM MDT SAT JUL 1 2000

SFC LOW LOCATED IN NORTHWEST SD AT 18Z WITH A TROF EXTENDING BACK
THROUGH BHK-GDV-OLF-WVN LINE ACROSS CWA. EAST OF THE LINE DEW POINTS
IN THE 50S... AND OVER IN ND GARRISON ALREADY WITH A DEW POINT OF 70.
THIS AIRMASS IS BEING FORCED EASTWARD WITH THE HEATING OF THE DAY.
YESTERDAY THE AIRMASS CAME BACK THROUGH GGW AROUND 7PM...WOULD
EXPECT A REPEAT TONIGHT. TEMPS THIS AFTERNOON... THE 80/90 LINE IS
THROUGH JDN-GGW-WKO WITH THE 90/S EAST AND 80/S WEST.

LOOKING AT THE MODELS TODAY...SHOWS A SIMILAR VIEW OF THE GENERAL
PATTERN. ALL MODELS MISSED THE ENHANCED AREA OF MOISTURE OVER NC MT
THIS EARLY AFTERNOON. HOWEVER THE ETA DID INIT WELL AND HAD A GOOD
HANDLE OF THE SITUATION AT 18Z. RUNS HAVE BEEN PRETTY CONSISTENT AS
WELL WITH THE MODEL OVER NEMONT.

SW FLOW WILL CONTINUE THROUGH THE SHORT TERM AS THE H5 LOW SLOWLY
MAKES IT/S WAY ACROSS BC. SHORTWAVES WILL SLIDE THROUGH THE PATTERN.
FIRST EXPECTED WAVE WILL BE TONIGHT OVER NEMONT...IT SHOULD START
EFFECTING THE SW BY 02Z AND WILL SLIDE OUT OF THE REGION AROUND 12Z.
ON THE SURFACE... THE TROF/DRYLINE/WARM FRONT FEATURE ACROSS NEMONT
WILL SLIDE BACK TO THE WEST WITH THE SETTING SUN...THIS WILL BRING
THE MOIST LOW-LEVEL AIR BACK INTO GGW/MALTA/JORDAN REGIONS BY
MORNING. ETA...THETA E RIDGE WHICH IS OVER SASK/ND AT 18Z TODAY WILL
BE OVER GGW-YYN LINE BY 18Z SUN. WITH YET ANOTHER SHORTWAVE MOVING
THROUGH THE FLOW REACHING NEMONT IN MID TO LATE AFTERNOON. MONDAY
THE PATTERN SLIGHTLY SHIFTS EAST...HOWEVER MY EASTERN ZONES COULD
SEE YET ANOTHER DAY OF TSRA. WITH PRETTY MUCH THE SAME CONDITIONS.

SVR WX...TONIGHT...MORE STRONG AND GUSTY WINDS FOR THE WEST IN AND
AROUND TSRA WITH HIGHER BASED STORMS. OVERNIGHT IN THE EAST A CHC OF
SVR WITH LRG HAIL AND GUSTY WINDS. TOMORROW IS A MUCH BETTER DAY FOR
A WIDESPREAD SVR EVENT. LOW LEVEL EASTERLIES...GOOD SHEAR...BETTER
TIMED SHORTWAVE... AND THE LIST GOES ON. MONDAY EVEN LOOKS GOOD FOR
SVR IN THE EAST...HOWEVER WILL NOT ADDING WORDING FOR SVR YET.

TEMPS...WILL GO WITH THE HIGHER END OF THE MODEL GUIDANCE TEMPS FOR
SUNDAY AND MONDAY FOR HIGHS...WILL TREND ABOVE GUIDANCE ON LOWS
THROUGH THE SHORT TERM.

WINDS ACROSS THE CWA...SHOULD BE NW THROUGH THE PERIOD IN THE
WESTERN ZONES...DAY/NIGHT SWITCH FROM NW TO NE IN THE CENTRAL
ZONES...WITH EAST WINNING OUT IN THE EASTERN ZONES. WILL ADD STRONG
AND GUSTY WINDS IN AND AROUND TSRA FOR TONIGHT ALL ZONES...WILL ALSO
ADD HAIL POSS FOR THE NE.                     PROTON

EXTENDED...ALL MODELS IN PRETTY GOOD AGREEMEMT WITH RIDGE AXIS
SHIFTING EAST AS WEST COAST TROF SPLITS. CLOSED LOW MOVES INTO
ALBERTA EARLY IN THE PERIOD AND THEN WEAKENS AS BASE OF TROF DIGS
FURTHER SOUTH ALONG WEST COAST BEFORE STRENGTHENING LATE IN THE
PERIOD. MONTANA REMAINS IN SOUTHWEST FLOW REGIME WITH SHORTWAVE
ACTIVITY. MAIN WAVE MOVES ALONG CANADIAN BORDER WITH UPPER LOW
MONDAY/TUESDAY. CYCLOGENESIS FURTHER SOUTH TO FOCUS PRECIP OVER
NORTHEAST MONTANA. WILL BREAKOUT MONDAY NIGHT FOR SHOWERS LIKELY
THEN LOWER CHANCE ON TUESDAY. WEDNESDAY ALTHOUGH HEIGHTS LOWER FOR A
BREAK IN THE HEAT. HEIGHT LOWERING WITH UPPER TROF SUPRESSING RIDGE
FOR A BREAK FROM THE HEAT. BY WEDNESDAY AIRMASS DRIES OUT...HOWEVER
WITH WEAK ENERGY MOVING THROUGH SOUTHWEST FLOW WILL KEEP MENTION OF
THUNDERSTORMS. SIMILAR ON THURSDAY ONLY WARMER WITH RIDGE REBOUNDING
TO THE WEST. EBERT

GGW TTWBT 062/083 060/080 058/079 055/082 055/085 946666/90333
GDV TTWBT 063/086 059/085 058/081 055/083 055/086 946666/90433