Severe Thunderstorm Warning 24, NWS Missoula, MT

000 
WWUS55 KMSO 210353
SVSMSO

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
952 PM MDT WED JUN 20 2007

MTC047-063-210402-
/O.EXP.KMSO.SV.W.0024.000000T0000Z-070621T0400Z/
MISSOULA MT-LAKE MT-
952 PM MDT WED JUN 20 2007

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN LAKE AND NORTHERN 
MISSOULA COUNTIES EXPIRES AT 1000 PM MDT...

LAT...LON 4762 11363 4760 11361 4760 11348 4754 11348
      4744 11379 4759 11392 4770 11365 4770 11361

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
906 PM MDT WED JUN 20 2007

.UPDATE...INCREASED PRECIPITATION CHANCES THIS EVENING OVER
NORTHERN IDAHO AND MAINLY SOUTHWEST MONTANA FOR THIS EVENING AS A
A LARGE AREA OF RAINFALL WITH ISOLATED THUNDERSTORMS CONTINUES TO
REMAIN FAIRLY ORGANIZED AS IT MOVES THROUGH NORTH CENTRAL IDAHO.
ALSO INTRODUCED AREAS OF PATCHY VALLEY FOG FOR TONIGHT IN AREAS
THAT RECEIVED RAIN AND HAIL THIS AFTERNOON.

&&

.DISCUSSION...QUITE THE SUPERCELL THUNDERSTORM THAT MOVED OUT OF
NORTHEAST OREGON AND THROUGH THE US HIGHWAY 95 CORRIDOR NEAR SLATE
CREEK IDAHO AND POINTS EAST. GOLF BALL SIZED HAIL AND VERY HEAVY
RAIN WAS REPORTED WITH THIS CELL. THE REMNANTS OF THIS
THUNDERSTORM WILL CONTINUE TO BRING LIGHT TO MODERATE RAINFALL
OVER NORTH CENTRAL IDAHO AND PORTIONS OF SOUTHWEST MONTANA THIS
EVENING BEFORE DISSIPATING AFTER MIDNIGHT. ISOLATED THUNDERSTORMS
ARE STILL POSSIBLE OVER WEST-CENTRAL MONTANA TONIGHT AS MOISTURE
AND AND AN UNSTABLE AIRMASS REMAIN OVER THE REGION.

.AVIATION...AIR MASS WILL REMAIN UNSTABLE WITH VERY ISOLATED BUT
STRONG CELLS THROUGH MIDNIGHT OR SO. BRIEF HEAVY RAIN AND HAIL
APPEAR TO BE THE MAIN THREAT TO AVIATION. THERE IS THE THREAT FOR
CONVECTION AGAIN THURSDAY AFTERNOON...BUT IT SHOULD BE MORE
CONFINED TO SOUTHWEST MONTANA...AND WILL NOT BE AS STRONG. PLEASE
SEE APPROPRIATE TAFS AND TWEBS.

&&

.PREV DISCUSSION... /ISSUED 218 PM MDT WED JUN 20 2007/

DISCUSSION...TONIGHT THROUGH FRIDAY...A SHORTWAVE UPPER LEVEL
DISTURBANCE WILL CONTINUE TO MAKE ITS WAY THROUGH CENTRAL IDAHO
AND SOUTHWEST MONTANA THIS EVENING...HELPING TO PRODUCE
THUNDERSTORMS AND A FEW SHOWERS OVER THIS AREA. THE MAIN THREAT
WITH THESE STORMS WILL BE STRONG WINDS...LITTLE PRECIPITATION IS
EXPECTED. SOUTHWEST FLOW WILL BRING CONTINUED WARM TEMPERATURES
AND THE THREAT OF ISOLATED AFTERNOON THUNDERSTORMS THROUGH
FRIDAY.

FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE UPPER RIDGE AXIS WILL BE
EAST OF THE CONTINENTAL DIVIDE WITH A WELL DEVELOPED LOW PRESSURE
SYSTEM MEANDERING JUST OFF VANCOUVER ISLAND. THE RESULTANT SOUTHWEST
FLOW ALOFT WILL BE QUITE ORGANIZED WITH SPOKES OF ENERGY SWEEPING
NORTHEAST THROUGH THE NORTHERN ROCKIES REGION. TIMING OF THESE MINOR
FEATURES WILL BE MORE DIFFICULT TO PIN DOWN...BUT THE GENERAL SENSE
OF THE FORECAST WILL BE GENERALLY UNSTABLE AND BREEZY WITH A COOLING
TREND...ESPECIALLY BY SUNDAY MORNING. MEDIUM RANGE MODELS ARE IN
FAIR AGREEMENT WITH THE LARGE SCALE FEATURES.

SUNDAY THROUGH MONDAY...THE UPPER LOW SYSTEM MOVES INLAND AND OPENS
UP INTO A TROUGH. A COOLER AIR MASS WILL BE USHERED IN BY BREEZY
LOW-LEVEL WESTERLY WINDS. COOLER TEMPERATURES WITH LOW CHANCE
POPS WILL PREDOMINATE THROUGH THIS PERIOD.

TUESDAY...A RIDGE OF HIGH PRESSURE IS EXPECTED TO RETURN TO THE
REGION OFFERING DRY...WARMER CONDITIONS.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
ID...NONE.
&&

UPDATE...CHURCH
PREVIOUS DISCUSSION...STEGEMILLER/JOHNSON
AVIATION...WHITMORE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
733 PM MDT WED JUN 20 2007

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

0634 PM     HAIL             SLATE CREEK             45.64N 116.28W
06/20/2007  E1.75 INCH       IDAHO              ID   PUBLIC

&&

WHITMORE