Severe Thunderstorm Warning 33, NWS Glasgow, MT

NORTHEAST MONTANA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
239 PM MDT SUN JUL 2 2000

ON THE SFC AT 18Z...DRY LINE ACROSS MY CENTRAL CWA AGAIN TODAY. LOW
SC OVR MY NORTHEAST KEEPING THEM IN THE 60S WITH DEW POINTS IN THE
MID 50S. 60 DEW POINTS IN SOUTHERN AND SOUTHWESTERN ND SHOULD ONCE
AGAIN RIDE UP THE DRY LINE THIS LATE AFTERNOON AND EVENING AS IT
MAKES IT/S SWING BACK ACROSS THE CWA. LAST NIGHT TORNADIC SUPERCELLS
DEVELOPED OFF THE DRYLINE IN WESTERN SASK...AND MOVED INTO NEMONT
OVERNIGHT. OUTFLOW BOUNDARY MADE IT ALL THE WAY INTO GGW FROM THEM.
TODAY IS A BIT DIFFERENT WITH THE LOW CLOUDS OVER THE EAST.

ON THE VIS SAX PIX...LOW CLOUDS ARE STUBBORN...BUT ARE MOVING NORTH
AND EAST OUT OF THE AREA. NEAR SDY OVR THE BIG SHEEP UPLANDS CU
FIELDS ARE FORMING ALREADY. ELSEWHERE AROUND MT A FEW TSRA ARE NOTED
IN THE CENTRAL MOUNTAINS AND ARE MOVING INTO THE PLAINS EAST OF HVR
MOSTLY NORTH OF THE LITTLE ROCKIES RANGE IN MY FAR WESTERN CWA.
OTHERWISE CLEAR SKIES RULE...WITH ONLY SOME FAIR WEATHER CU NOTED
HERE AT GGW AT 19Z.

ON THE MODEL FRONT...POOR SFC FIELDS BY ALL COMPUTER GUESSES TODAY.
ETA DID NOT INIT WELL WITH 400MB RH FIELDS...AVN DID A BETTER JOB.
HOWEVER THE AVN LOOKS A BIT ODD IN THE LATER PERIODS. NGM HAS AN OK
SOLUTION COMPARABLE TO THE ETA. WILL MIX AND MATCH THE MODELS FOR
THE FORECAST SOLUTION TODAY.

12Z SOUNDINGS...HERE AT KGGW...AN ALMOST LOADED GUN SOUNDING SHAPING
UP FOR GGW. -4 LI... PW 1.06...CAPE AROUND 1000 J/KG. KTFX SOUNDING
A MORE TAMER OF THE TWO. AT 17Z ON THE GOES SOUNDER DATA... -7 LI/S
OVER MY CWA WITH THE -3/S GOING ALL THE WAY BACK OVER THE WESTERN
MOUNTAINS. CAPES IN THE 1000 J/KG DISTRICT.

19Z SOUNDING...NEW VIEW INTO THE UPPER LEVELS...SHOWS A GOOD CAP AT
540 MB WHICH WOULD TAKE A 92 DEGREE SURFACE TO SURPASS....LOWER CAP
AT 720MB WOULD TAKE A TEMP OF 87 TO BREAK. GOOD DIRECTIONAL AND
SPEED SHEAR NOTED WITH THE SPECIAL SOUNDING. CAPE AROUND 800-900
J/KG.

FOR TONIGHT...SVR WX IS POSSIBLE ACROSS THE AREA. SW WITH HIGH BASED
TSRA COMING OFF THE WESTERN MTS (AT 19Z SOME STRIKES IN THE SW MTS
ALREADY) MAKING IT INTO THE PLAINS...MAIN THREAT WILL BE HIGH WINDS.
THE NE IS PRIMED UP WITH PLENTY OF LOW LEVEL MOISTURE...GOOD SHEAR
PROFILE...ETC FOR LARGE HAIL AND HIGH WINDS.

MONDAY...LOOKS BETTER FOR SVR. THE NE COULD EVEN BE IN A MODERATE
RISK WITH THE ELEMENTS ALL THERE FOR A BIG EVENT. WILL EVEN
HIGHLIGHT IN THE ZONES FOR SVR NE. ALONG THE MISSOURI RIVER AN AREA
OF 3000 J/KG OF CAPE SHOWS UP AND MOVES NE THROUGH THE REGION. WITH
THE DEVELOPING SFC LOW IN THE REGION...LOOK FOR A STRONGER E/SE WIND
CWA WIDE TO AIDE IN BRINGING MORE LOW LEVEL MOISTURE INTO THE
REGION. EVEN ON INTO THE OVERNIGHT PERIOD ON MONDAY AN 850MB LOW
LEVEL JET WRAPS INTO THE REGION STRAIGHT FROM GULF OF MEXICO...JUST
TO ADD TO THE PILE OF SVR ELEMENTS.

TUESDAY...WITH THE CURRENT MODEL TREND...SEEMS TO LOOK A BIT TAMER
FOR NEMONT...BUT VERY WELL COULD BE ANOTHER SVR WEATHER OVER THE
EASTERN ZONES.

TEMPS...WILL TREND ABOVE GUIDANCE FOR THE SHORT TERM.             PROTON

EXTENDED...PATTERN CONTINUES WITH SOUTHWEST FLOW ALOFT INTO MONTANA
FROM TROF ALONG WEST COAST. RIDGE REBUILDING OVER HIGH PLAINS
WEDNESDAY WITH THICKNESS VALUES INCREASING AGAIN FOR TEMPERATURE
HEADING BACK TOWARD 90. SHORTWAVES GET EJECTED FROM WEST COAST TROF
ACROSS MONTANA THROUGH THE PERIOD. MODELS HAVE BEEN INCONSTANT ON
SPEED AND POSITION OF SHORT WAVE ENERGY AND ATMOSPHERE REMAINING AT
LEAST MARGINALLY UNSTABLE WILL EXPECT THUNDERSTORM DEVELOPMENT EACH
DAY. EBERT

GGW TTTTT 060/088 060/080 055/082 056/086 059/088 946654/90333
GDV TTTTT 063/088 062/080 055/083 056/087 058/087 946654/90333