Severe Thunderstorm Warning 44, NWS Glasgow, MT

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
215 PM MDT MON JUL 2 2001

FINALLY STARTING TO SEE CONVECTION PRODUCING LIGHTNING...BUT NOWHERE
NEAR SEVERE YET. DID A SPECIAL 17Z SOUNDING AND STILL SHOWED VERY
UNSTABLE CONDS OVER GGW THIS AFTERNOON. CAPES STILL OVER 2000 WITH
AND LI OF -6. THINK LIMITING FACTORS ARE: A VERY WEAK INVERSION AT
AROUND 850 MBS AND DRY AIR EDGING IN FROM CANADA AT THE SFC. BESIDES
INVERSION...LAPSE RATES ARE PRETTY STEEP. MESOETA SHOWS A WEAK VORT
MAX MOVING THROUGH CENTRAL PORTION OF CWA BETWEEN 21 AND 00Z WHICH
MAY BE JUST ENOUGH TO SPARK DEEPER CONVECTION. PROGS ALSO SHOW A
FAIRLY STRONG VORT COUPLET CLIPPING THE NE CORNER OF MY CWA. THERE
IS ALSO A 50KT JET AT H5 IN THE SAME AREA...WHICH HISTORICALLY
SUPPORTS SEVERE CONVECTION OVER NEMONT. SHEAR PROFILES ARE MARGINAL
SO MAIN THREAT FROM ANY CELLS THAT DEVELOP WILL BE HAIL AND WIND.
WAS PLANNING TO KEEP MAINLY EVENING POPS...SINCE DAYTIME HEATING IS
MAIN TRIGGER...BUT WILL CARRY 30 POPS ALL NIGHT IN SRN ZONES PER
COORDINATION WITH BIL.

WEAK SFC HIGH PRESSURE MAY FINALLY BE ABLE TO MOVE IN OVER NEMONT
TONIGHT. WE SHOULD SEE DRIER AIR AT THE SFC TOMORROW AND WARMER
AFTERNOON TEMPS WITH LESS CUMULUS DEVELOPMENT. WE CAN/T SEEM TO
SHAKE THE UPWARD MOTION...HOWEVER...AND WITH SOME WEAK IMPULSES IN
THE NW FLOW ALOFT WILL STILL HAVE TO HAVE A 20 POP FOR THUNDER
TOMORROW AFTERNOON.

RIDGE STRENGTHENS A LOT OVER WRN MT ON WED WITH H5 THICKENESSES OVER
NEMONT RISING ABOUT 200 M BETWEEN TUE AND WED. PROGS GENERALLY
SHOWING HIGHS AROUND 90 ON WED SO WON/T STRAY FAR FROM THAT. FLOW
BECOMES WEAK SRLY ON WED WITH DEWPOINTS CREEPING BACK UP INTO THE
50S...EVEN LOW 60S OVER THE SE. DECENT VORT MAX COMES THROUGH THE
RIDGE DURING THE AFTERNOON WED. AVN HAS A STRONGER VORT THAN ETA BUT
KEEPS IT OVER SRN MT. EITHER WAY...WILL CONTINUE TO CARRY 20 POP FOR
THUNDER THROUGH WED.  WRIGHT

EXTENDED...RIDGE HOLDS IN FOR THE EARLY PART OF THE EXTENDED...THEN
IS BROKEN DOWN SOME WITH THE PASSAGE OF A GOOD H5 SHORTWAVE LATE
THURSDAY INTO FRIDAY...THEN A ZONAL FLOW. HEIGHTS ARE UP THERE AT
MID SUMMER LEVELS ON THURSDAY...90S ARE REALISTIC FOR THE REGION.
WILL ADD CHC TSRA FOR THURSDAY. CURRENT EXTENDED SEEMS TO HAVE A
GOOD HANDLE ON TEMPS WILL CONTINUE WITH STATUS QUO FOR NOW.   PROTON

KGGW 057/085 061/090 056/090 058/083 052/080 057/087 059/087
      BUTTUUU  953202/9433111
KGDV 055/086 061/091 052/090 057/085 052/081 053/088 056/088
      BUTTUUU  953202/9433111

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
109 PM MDT MON JUL 2 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0746 AM    2 SW FALLON               MT   .75 INCH HAIL
07/02/01   PRAIRIE

0904 AM    17 NW FALLON              MT   .88 INCH HAIL
07/02/01   PRAIRIE

0934 AM    18 W (GDV)GLENDIVE-DAWSON MT   1.75 INCH HAIL
07/02/01   DAWSON

0950 AM    3 SE GLENDIVE             MT   .75 INCH HAIL
07/02/01   DAWSON                         COVERING GROUND

PMG