Severe Thunderstorm Warning 9, NWS Great Falls, MT

752 
WUUS55 KTFX 082302 COR
SVRGTF
MTC101-082330-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING...CORRECTION...REMOVE PONDERA COUNTY
NATIONAL WEATHER SERVICE GREAT FALLS MT
501 PM MDT THU JUN 8 2000

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  TOOLE COUNTY IN NORTH CENTRAL MONTANA
  THIS INCLUDES THE CITY OF SHELBY

* UNTIL 530 PM MDT

* AT 457 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 6 MILES SOUTHWEST OF SHELBY...MOVING NORTHEAST
  AT 25 MPH.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN GREAT FALLS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT
THURSDAY EVENING FOR NORTHWESTERN MONTANA.

LAT...LON 4846 11213 4833 11194 4860 11149 4881 11180

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT THU JUN 8 2000

POTENT SEVERE WEATHER PATTERN FOR LATE THIS AFTERNOON INTO EARLY
TONIGHT...ESPECIALLY FOR NORTH CENTRAL MONTANA. EXPECT A WATCH FAIRLY
SOON FROM SPC. LOW LEVEL MOIST EASTERLY FLOW OVER NORTHERN PORTIONS WITH
SURFACE LOW DEVELOPING SOUTHWEST MONTANA AND MOVING INTO CENTRAL MONTANA
THIS EVENING. GOOD HELICITY FOR POSSIBLE TORNADOS WITH PATTERN. WOULD
LIKE TO SEE A SHORT WAVE...WHICH THE PROGS FORECAST FOR EARLY TONIGHT
NEAR THE CONTINENTAL DIVIDE...BUT PROBABLY TOO LATE FOR CONVECTION NORTH
CENTRAL MONTANA. HOWEVER THIS SHORT WAVE MAY KEEP GENERAL SHOWERS AND
THUNDERSTORMS GOING AFTER SEVERE WEATHER INTO LATE TONIGHT. DRY SLOT IN
SOUTHWEST MONTANA THIS AFTERNOON WITH TEMPERATURES QUITE WARM WILL BE
MOVING NORTHWARD ALOFT AND SUCK UP THE LOW LEVEL MOISTURE FOR POSSIBLE
SEVERE WEATHER. PROGS FORECAST DOWNSLOPE LATE TONIGHT ON PLAINS AS
NORTHERN BRANCH OF TROUGH MOVES INTO AREA. SCATTERED SHOWERS WITH
ISOLATED THUNDERSTORMS EXPECTED TO MOVE INTO SOUTHWEST MONTANA LATE
TONIGHT FROM IDAHO. DOWNSLOPE PLAINS LATE TONIGHT AND FRIDAY WILL DRY
OUT MANY SHOWERS. NEXT TROUGH DUE INTO PACIFIC NORTHWEST
SATURDAY...WHICH SHOULD START MORE CONVECTION IN AREA SATURDAY
AFTERNOON. OARD

EXTENDED DISCUSSION...LIKE MODEL RUNS THAT WERE AVAILABLE FOR WEDNESDAY
AFTERNOONS FORECAST...LATEST AVAILABLE MODEL RUNS OFFER WIDELY VARYING
SOLUTIONS IN THE 3 TO 5 DAY PERIOD. MODELS START OFF SUNDAY MORNING
REASONABLY SIMILAR WITH AN UPPER LOW OR UPPER TROUGH OVER WA. BUT THEN
SOLUTIONS DIVERGE. ECMWF TAKES THE UPPER LOW INTO SRN ID ON MON AND THEN
TAKES IT SW TO NEAR RNO BY 12Z WED. NOGAPS LIKE YESTERDAY IS MORE
PROGRESSIVE. IT HAS THE UPPER LOW INTO SRN SASK BY MONDAY MORNING AND N
OF THE GREAT LAKES ON WED. MRF OFFERS SOMEWHAT OF A COMPROMISE SOLUTION.
IT HAS UPPER LOW INTO SRN ALTA BY MON MORNING AND THEN DROPS IT INTO ND
BY WED MORNING. CMC HAS BROAD UPPER TROUGH GRADUALLY MOVING E AND HAS IT
E OF FORECAST AREA ON TUE. LATEST AVN EXTENSION IS WEAKER AND MORE
PROGRESSIVE THAN THE MRF RUN. NCEP FAVORS THE MRF SOLUTION BUT LEAVES
OPEN THE POSSIBILITY THAT THE AVN EXTENSION COULD BE BEST. PER NCEP
DISCUSSION WILL GO ALONG WITH THE MRF SOLUTION. BLANK
CCF NUMBERS
GTF NB 050/070 043/072 044 166312
CTB NB 046/065 040/067 040 166312
HLN NB 054/070 045/074 046 164312
BZN EB 050/070 042/075 042 163312
WEY EB 037/062 030/070 033 163312
DLN EB 047/067 040/072 040 163312
HVR EB 055/074 048/076 047 167331
LWT EB 052/070 042/072 040 166331