Hail and Damaging Winds in Montana, July 26 to 27, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
217 PM MDT SAT JUL 26 2008

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
SEVERE THUNDERSTORMS POSSIBLE IN THE CWA TONIGHT THROUGH MONDAY.

ALL EYES THIS AFTERNOON ARE ON THE CONVECTIVE POTENTIAL FOR THIS
AFTERNOON AND EVENING. MODELS APPEAR TO BE A BIT TOO SLOW WITH IT/S
FORWARD SPEED. BIGGEST LIMITING FACTOR IS THE CAP OVER THE AREA.
ACTIVITY SHOULD WANE A BIT OVERNIGHT BUT AXIS OF INSTABILITY REMAINS
OVER THE AREA INTO SUNDAY. WITH CAPES OVER 1000 J/KG OVER THE
AREA...THERE STILL REMAINS THE POSSIBILITY OF SEVERE TSTORMS BUT THE
SHEAR MAY WEAKEN ON SUNDAY. SURFACE TROUGH DOES NOT LOOK TO EXIT
AREA UNTIL MONDAY (LATEST WITH NAM SOLUTION). THE EASTERN ZONES LOOK
TO BE MORE PRIMED MONDAY...BUT THE MORE CONSISTENT GFS IS SHOWING
THE SURFACE TROUGH TO BE EAST OF THE CWA BY 00Z TUESDAY. JAMBA

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
12Z GFS/ECMWF/CANADIAN ALONG WITH GFS ENSEMBLE MEMBERS ALL AGREE
FAIRLY WELL WITH THE SYNOPTIC PATTERN THROUGH WEDNESDAY. WEDNESDAY
NIGHT AND BEYOND THE MODELS THEN DIVERGE AS THEY ATTEMPT TO BRING
THE GULF OF ALASKA TROUGH ONSHORE.

SHORTWAVE RIDGING BUILDS IN MONDAY NIGHT BEHIND DEPARTING
SHORTWAVE TROUGH. LOWERED SKY COVER MONDAY NIGHT AND TUESDAY BASED
ON RISING HEIGHTS AND LOW MEAN LAYER RELATIVE HUMIDITY
VALUES...WHICH DOES NOT SUPPORT MUCH CLOUD COVER. ANOTHER PACIFIC
SHORTWAVE TROUGH QUICKLY APPROACHES WEDNESDAY NIGHT. UPPER HEIGHT
FALLS AND A LEE SIDE SURFACE TROUGH SUPPORT THUNDERSTORM DEVELOPMENT.
THE CHANCE OF THUNDERSTORMS WILL CONTINUE INTO WEDNESDAY BEFORE
THE TROUGH AXIS SWINGS THROUGH AND DRIVES THE SURFACE TROUGH TO
THE EAST.

THE ONLY CHANGES WERE THE AFOREMENTIONED SKY GRIDS. OTHERWISE THE
REMAINDER OF THE GRIDS HANDLE THE SITUATION WELL. AJZ

PREVIOUS SHORT TERM DISCUSSION...
THERE IS GENERAL AGREEMENT IN THE INITIAL PERIODS OF EXTENDED
MODELS. AN UPPER SHORTWAVE WILL BE EXITING THE REGION MONDAY NIGHT
WITH THE POSSIBILITY OF DIMINISHING THUNDERSTORMS FROM THE
PREVIOUS AFTERNOON. INHERITED POPS ARE VERY APPROPRIATE FOR MONDAY
NIGHT. AMPLIFIED UPPER RIDGING TUESDAY WILL LIKELY MAINTAIN DRY
CONDITIONS. HOWEVER MODELS SHOW A TROUGH PUSHING INTO THE
NORTHWEST LATE TUESDAY. UPPER FLOW WILL TURN SOUTHWEST AS A FRONT
PASSES THROUGH THE CWA OVERNIGHT...GENERATING A CHANCE FOR STORMS
INTO WEDNESDAY. RIDGING MOVES IN WEDNESDAY NIGHT BUT THEN THE
MODELS BEGIN TO DIFFER IN TREATMENT OF ANOTHER TROUGH MOVING INTO
CANADA. WILL GO CONSERVATIVE FOR NOW AND MAINTAIN A WEAK RIDGE IN
THE LATER PERIODS. EXTENDED PERIOD TEMPERATURES WILL REMAIN AT OR
ABOVE NORMAL. SCT

&&

.AVIATION...
PREDOMINANTLY VFR TONIGHT AND SUNDAY. THUNDERSTORMS ARE POSSIBLE
TONIGHT AND THEN AGAIN SUNDAY AFTERNOON...SOME OF WHICH COULD BE
SEVERE...AND TEMPORARILY PRODUCE MFVR CONDITIONS. THE WIND WILL BE
OUT OF THE EAST AT 10 TO 20KT WITH HIGHER GUSTS OF VARIABLE
DIRECTION IN AND AROUND ANY THUNDERSTORMS. AJZ

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

WEATHER.GOV/GLASGOW

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
337 AM MDT SAT JUL 26 2008

MTZ016>027-059>062-270945-
CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-
DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE-
RICHLAND-DAWSON-PRAIRIE-WIBAUX-NORTHERN PHILLIPS-
SOUTHWEST PHILLIPS-NORTHERN VALLEY-EASTERN ROOSEVELT-
337 AM MDT SAT JUL 26 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...TODAY AND TONIGHT

AN UPPER WAVE MOVING TOWARD THE REGION IS EXPECTED TO TRIGGER SOME
THUNDERSTORMS TODAY...SOME OF WHICH MAY BE SEVERE DURING THE EVENING.
THE BEST CHANCES FOR THIS TO OCCUR ARE SOUTH AND WEST OF A LINE
FROM MALTA TO SIDNEY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

ON SUNDAY...A BETTER COVERAGE OF THUNDERSTORMS ARE EXPECTED. SOME
OF THESE AGAIN MAY BE SEVERE AND BE MORE WIDESPREAD ACROSS THE
AREA COMPARED TO TODAY.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.