Severe Thunderstorm Warning 111, NWS Great Falls, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
237 PM MDT FRI AUG 8 2008

.DISCUSSION...

TONIGHT THROUGH SUNDAY...THE AIRMASS HAS BECOME UNSTABLE AND SHOWERS
ARE MOVING THROUGH SOUTHWEST MONTANA. THESE WILL SPREAD NORTH AND
EAST THROUGH LATE AFTERNOON AND EVENING. LARGE HAIL IS NOT EXPECTED
HOWEVER STRONG GUSTY WINDS ARE POSSIBLE. AN UPPER LEVEL LOW PRESSURE
SHORTWAVE OVER THE ZONES WILL MOVE EAST AND THUNDERSTORM ACTIVITY
WILL ALSO MOVE EAST WITH ACTIVITY DECREASING DURING THE EVENING
BEHIND THIS SHORTWAVE. ALTHOUGH CONVECTION WILL NOT BE AS
WIDE-SPREAD ON SATURDAY...THE SUPPORT FOR ORGANIZED CELLS IS MORE
INTERESTING. THE AIRMASS WILL STILL BE RELATIVELY MOIST FOR THIS
TIME OF THE YEAR AND SHEAR WILL BE STRONG ENOUGH TO LEND SUPPORT TO
LONGER LASTING CELLS. BY SATURDAY NIGHT...A DEEP LOW PRESSURE
SYSTEM  MOVES EAST...AND A COLDFRONT WILL BE APPROACHING THE
ROCKIES. THIS COLDFRONT MOVES ACROSS THE ROCKIES SUNDAY MORNING AND
ACROSS THE ZONES DURING THE DAY. THE AIRMASS WILL BE UNSTABLE DURING
THE AFTERNOON AHEAD OF THIS FRONT AND THUNDERSTORM ACTIVITY WILL
AGAIN DEVELOP. AT THIS TIME...THE EASTERN ZONES APPEAR TO HAVE A
BETTER CHANCE FOR THUNDERSTORM ACTIVITY...AREAS BEHIND THE FRONT
WILL BE WINDY BUT GENERALLY FREE FROM CONVECTION. TEMPS WILL REMAIN
WELL ABOVE NORMALS THROUGH SATURDAY NIGHT BUT DROP CLOSER TO NORMALS
ON SUNDAY. ZELZER

SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...NO SIGNIFICANT CHANGES FOR
THE PERIOD FROM PREVIOUS FORECAST. MODELS SHOWING BETTER AGREEMENT
AND RUN-TO-RUN CONSISTENCY. UPPER LEVEL LOW TO TRACK ACROSS
SOUTHERN/CENTRAL ALBERTA AND SASKATCHEWAN WITH SOUTHERN PORTION OF
TROUGH DRAGGING ACROSS CWA MONDAY AND EARLY TUESDAY. AS TROUGH
TAPS INTO SOUTHWEST MONSOONAL MOISTURE...SMALL EMBEDDED WEATHER
SYSTEMS WILL PROVIDE ENOUGH DYNAMICS TO SET OFF A FEW SHOWERS AND
THUNDERSTORMS. LOW CENTER THEN EXPECTED TO DROP TO THE
SOUTHEAST...CLIPPING NORTHEAST MONTANA...TUESDAY NIGHT AND EARLY
WEDNESDAY. AGAIN...A FEW SMALL WEATHER SYSTEMS WILL DRAG ACROSS
THE CWA SETTING OFF A FEW SHOWERS AND THUNDERSTORMS... MAINLY
NORTH. MONDAY WILL LIKELY SEE THE COOLEST DAYTIME HIGH
TEMPERATURES WITH TUESDAY MORNING HAVING THE COOLEST OVERNIGHT
LOWS. OVERALL...TEMPERATURES SHOULD BE JUST A FEW DEGREES BELOW
NORMAL. TROUGH SLOWLY DRIFTS ACROSS THE DAKOTAS WEDNESDAY AS HIGH
PRESSURE BEGINS REBUILDING OVER THE CWA FOR MOSTLY DRY CONDITIONS
AND SLIGHTLY WARMER TEMPERATURES.

THURSDAY THROUGH FRIDAY...MODELS INDICATE A QUASI-STATIONARY UPPER
LEVEL RIDGE OF HIGH PRESSURE LINGERING OVER THE ROCKIES DURING THIS
PERIOD. WARM AND DRY CONDITIONS ARE EXPECTED. HOWEVER...LIMITED
MONSOONAL MOISTURE WORKS ITS WAY NORTHWARD FOR A FEW MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...MOSTLY OVER THE
CENTRAL AND SOUTHWEST MOUNTAINS. TEMPERATURES ARE EXPECTED TO BE
JUST A FEW DEGREES ABOVE SEASONAL AVERAGES.  EK
&&

.AVIATION...
UPDATED 1729Z.
THUNDERSTORM ACTIVITY WILL INCREASE AGAIN THIS AFTERNOON/EVENING
WITH MOIST AND INCREASINGLY UNSTABLE AIRMASS IN PLACE WITH A WEAK
DISTURBANCE MOVING IN FROM THE SW. STRONGER CELLS WILL AGAIN HAVE
THE POTENTIAL TO PRODUCE GUSTY WINDS AND SMALL HAIL...WITH AN
ISOLATED THREAT OF LARGE HAIL AND GUSTS IN EXCESS OF 50KTS.
THUNDERSTORMS WILL DIMINISH BY MIDNIGHT...HOWEVER ISOLATED SHOWERS
AND THUNDERSTORMS MAY LINGER THROUGH 8Z OVER EASTERN AREAS.
OCCASIONAL MVFR/IFR CONDITIONS ARE POSSIBLE IN CONVECTION WITH VFR
CONDITIONS PREVAILING ELSEWHERE. HOENISCH

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  61  93  57  84 /  50  30  30  20
CTB  57  88  53  75 /  40  20  30  20
HLN  63  93  60  84 /  60  30  30  20
BZN  56  95  54  89 /  60  30  40  20
WEY  49  78  49  76 /  50  40  30  30
DLN  56  85  52  80 /  80  40  30  20
HVR  63  95  59  88 /  40  20  40  20
LWT  59  90  55  83 /  50  20  40  30

&&

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

WEATHER.GOV/GREATFALLS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
558 AM MDT FRI AUG 8 2008

MTZ008>015-044>055-091200-
BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-
CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-
TOOLE-LIBERTY-EASTERN PONDERA-BLAINE-
SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS-
JEFFERSON-BROADWATER-MEAGHER-GALLATIN-
558 AM MDT FRI AUG 8 2008

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE POSSIBLE TODAY AND TONIGHT. SOME
THUNDERSTORMS MAY BECOME STRONG WITH GUSTY WINDS...HEAVY
RAIN AND SMALL HAIL.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SCATTERED THUNDERSTORMS ARE POSSIBLE SATURDAY. SOME THUNDERSTORMS
MAY BECOME STRONG WITH GUSTY WINDS...HEAVY RAIN AND SMALL
HAIL.

.SPOTTER INFORMATION STATEMENT...

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
317 PM MDT FRI AUG 08 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0302 PM     TSTM WND GST     6 N LAKEVIEW            44.68N 111.83W
08/08/2008  M66.00 MPH       BEAVERHEAD         MT   MESONET

            GUST WAS MEASURED AT RED ROCK RAWS SITE.

&&

ACOHEN