Hail and Damaging Winds in Montana, May 10, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1140 AM MDT THU MAY 10 2007

.UPDATE...
DUE TO CLOUDS AND RAIN ACROSS NORTH CENTRAL MONTANA TEMPERATURES
ARE SLOW WARM UP THIS MORNING. WILL UPDATE AGAIN TO LOWER HIGH
TEMPERATURES ACROSS THE NORTH. MEIER

&&

.AVIATION...
UPDATED 1740Z.
A WEATHER DISTURBANCE WILL BE MOVING THROUGH THE AREA THE REST OF
THIS AFTERNOON AND THROUGH THIS EVENING. AHEAD OF IT THERE WILL
SHOWERS AND THUNDERSTORMS. IT LOOKS LIKE THE AREA FROM KCTB TO KHVR
WILL BE TOO STABLE FOR MUCH THREAT OF THUNDER. NEAR AND SOUTH OF A
LINE FROM KGTF TO KLWT EXPECT THE THREAT OF SOME STRONG
THUNDERSTORMS WITH A RISK OF WIND GUSTS TO 50 KNOTS AND HAIL. SOME
OF THESE STORMS WILL ALSO HAVE MVFR OR EVEN IFR CONDITIONS IN HEAVY
RIAN. SHOWERS AND THUNDERSTORMS WILL END IN THE WEST EARLY THIS
EVENING AND BY MIDNIGHT IN THE EAST. EXPECT CLEAR OR NEARLY CLEAR
SKIES LATE TONIGHT INTO EARLY FRIDAY MORNING. ALTHOUGH NOT INDICATED
IN THE TAFS THERE IS A SMALL THREAT OF FOG OR LOW CLOUDS AT KHVR AND
AT KLWT LATE TONIGHT AND EARLY FRIDAY MORNING. JMB

&&

.PREV DISCUSSION... (ISSUED 400 AM MDT THU MAY 10 2007)

DISCUSSION...
A RATHER ACTIVE...EARLY SUMMER LIKE WEATHER PATTERN SETTING UP OVER
THE REGION FOR THE NEXT FEW DAYS.

TODAY...A WEAK WARM FRONT IS PUSHING NORTH THROUGH THE REGION THIS
MORNING. THIS FRONT WAS LOCATED ALONG A LINE FROM JUST NORTH OF
DILLON TO LEWISTOWN. SHOWERS AND ISOLATED THUNDERSTORMS WERE
DEVELOPING ALONG THIS FRONT. THESE SHOWERS WILL GRADUALLY PUSH
NORTHWARD THROUGH NORTH CENTRAL MONTANA THIS MORNING. ANY PRECIP
WITH THIS ACTIVITY THIS MORNING WILL BE LIGHT THOUGH. FOR THIS
AFTERNOON...A STRONGER UPPER LEVEL DISTURBANCE WILL MOVE INTO
SOUTHWEST MONTANA...AS AN AREA OF SURFACE LOW PRESSURE MOVES EAST
ACROSS THE SOUTHERN PORTIONS OF MONTANA. THUNDERSTORMS WILL
REDEVELOP EARLY THIS AFTERNOON OVER SOUTHWEST MONTANA...THEN MOVE
NORTHEAST TOWARDS THE GREAT FALLS AND LEWISTOWN AREAS. THIS AREA OF
THUNDERSTORMS WILL BECOME MORE WIDESPREAD OVER CENTRAL/SOUTHWEST
MONTANA BY EVENING. A FEW STORMS WILL BE SEVERE...WITH DAMAGING
WINDS/HAIL. SEE HWO FOR MORE DETAILS. TEMPERATURES WILL BE SLIGHTLY
COOLER TODAY WITH CLOUDS/PRECIP...BUT STILL ABOVE NORMAL.

FOR TONIGHT...EXPECT SHOWERS AND THUNDERSTORMS DURING THE EVENING
HOURS...BUT MOST OF THIS ACTIVITY WILL DIMINISH BY MIDNIGHT AS THE
SURFACE AREA OF LOW PRESSURE PULLS TO THE EAST.

FOR FRIDAY/FRIDAY NIGHT...EXPECT A BIT WARMER TEMPERATURES TO MOVE
BACK INTO THE REGION...AS WEAK UPPER LEVEL RIDGING TAKES PLACE
ALOFT. A WEAK UPPER LEVEL DISTURBANCE WILL DEVELOP OVER SOUTHWEST
MONTANA DURING THE AFTERNOON HOURS...PRODUCING A FEW ISOLATED
THUNDERSTORMS OVER SOUTHWEST MONTANA...AND THE WESTERN PORTIONS OF
NORTH CENTRAL MONTANA. AT THIS TIME...MOST STORMS ARE EXPECTED TO
REMAIN BELOW SEVERE CRITERIA.

FOR SATURDAY...A MOIST SOUTHWEST FLOW WILL DEVELOP ALOFT...AS EVEN
WARMER AIR CONTINUES TO PUSH NORTHWARD INTO THE REGION. AFTERNOON
HIGHS ON SATURDAY WILL RANGE BETWEEN 15 AND 20 DEGREES ABOVE NORMAL.
ADDITIONALLY...ANOTHER ROUND OF SHOWERS/THUNDERSTORMS ARE EXPECTED
OVER THE REGION...SOME THUNDERSTORMS WILL BE SEVERE...AS THE AIRMASS
BECOMES QUITE UNSTABLE DURING THE AFTERNOON HOURS. BRUSDA

SATURDAY NIGHT THROUGH THURSDAY...THE UPPER LEVEL RIDGE OVER THE
DESERT SOUTHWEST IS PROGGED TO BREAK DOWN EARLY NEXT WEEK. SHORTWAVE
ENERGY WILL MOVE THROUGH THE REGION SATURDAY NIGHT FOR A CHANCE OF
SHOWERS AND THUNDERSTORMS...POSSIBLY SEVERE WITH LOCALLY HEAVY
RAINS. TEMPERATURES THAT ARE NEAR SEASONAL NORMS ALONG WITH
CONTINUED UNSETTLED CONDITIONS WILL PREVAIL SUNDAY AS THE FLOW ALOFT
TRANSITIONS TO A MORE WESTERLY FLOW BEHIND THE SHORTWAVE. MODELS ARE
IN DISAGREEMENT FOR MUCH OF EARLY AND MID WEEK WITH VARIOUS
DISTURBANCES TRANSITIONING THROUGH THE REGION AT TIMES SO HAVE
CONTINUED A BROAD-BRUSHED SLIGHT CHANCE TO CHANCE OF SHOWERS AND
THUNDERSTORMS WITH TEMPERATURES SLOWLY REBOUNDING ABOVE SEASONAL
NORMALS. BY NEXT THURSDAY IT APPEARS THAN AN UPPER LEVEL RIDGE COULD
BEGIN TO BUILD OVER THE NORTHERN ROCKY MOUNTAINS. MPJ

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  62  44  79  50 /  40  30  10  10
CTB  62  42  73  48 /  30  20  10  10
HLN  69  47  82  51 /  50  30  20  10
BZN  76  46  81  50 /  40  30  20  20
WEY  66  28  74  30 /  30  20  30  30
DLN  73  44  77  46 /  30  20  20  10
HVR  61  46  81  49 /  50  40  10  10
LWT  67  46  78  48 /  40  60  10  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...MEIER
LONG TERM...MPJ
AVIATION...BLANK

WEATHER.GOV/GREATFALLS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
900 AM MDT THU MAY 10 2007

MTZ008-012-014-015-050>055-111500-
BEAVERHEAD-CASCADE-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-
JUDITH BASIN-FERGUS-JEFFERSON-BROADWATER-MEAGHER-GALLATIN-
900 AM MDT THU MAY 10 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA
AND SOUTHWEST MONTANA.

.DAY ONE...TODAY AND TONIGHT

AS THE AIRMASS BECOMES UNSTABLE THIS AFTERNOON...THUNDERSTORMS
WILL DEVELOP OVER SOUTHWEST MONTANA. THESE STORMS WILL MOVE
NORTHEAST INTO CENTRAL MONTANA LATE THIS AFTERNOON AND EVENING. A
FEW OF THESE THUNDERSTORMS COULD BE SEVERE...WITH THE MAIN THREAT
BEING DAMAGING WIND GUSTS AND LARGE HAIL. THE BEST TIME FRAME FOR
THE SEVERE THUNDERSTORMS WILL BE FROM 3 PM THIS AFTERNOON...UNTIL
9 PM THIS EVENING.

LISTEN TO NOAA WEATHER RADIO...OR YOUR LOCAL MEDIA FOR THE LATEST
INFORMATION...FORECASTS...AND ANY POSSIBLE WATCHES OR WARNINGS
THAT COULD BE ISSUED LATER TODAY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

AN EARLY SUMMER LIKE WEATHER PATTERN WILL RESIDE OVER THE REGION
THROUGH SATURDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP DURING THE AFTERNOON AND EVENING HOURS ON SATURDAY. SOME
OF THESE STORMS COULD BE SEVERE. DAMAGING WIND GUSTS AND LARGE
HAIL WILL BE THE MAIN THREAT FROM ANY SEVERE THUNDERSTORMS THAT
DEVELOP.

.SPOTTER INFORMATION STATEMENT...

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

MTZ009>011-013-044>049-111500-
NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-CHOUTEAU-TOOLE-
LIBERTY-EASTERN PONDERA-BLAINE-SOUTHERN ROCKY MOUNTAIN FRONT-
EASTERN TETON-
900 AM MDT THU MAY 10 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
MONTANA.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

AN EARLY SUMMER LIKE WEATHER PATTERN WILL RESIDE OVER THE REGION
THROUGH SATURDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP DURING THE AFTERNOON AND EVENING HOURS ON SATURDAY. SOME
OF THESE STORMS COULD BE SEVERE. DAMAGING WIND GUSTS AND LARGE
HAIL WILL BE THE MAIN THREAT FROM ANY SEVERE THUNDERSTORMS THAT
DEVELOP.

.SPOTTER INFORMATION STATEMENT...

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