Severe Thunderstorm Warning 42, NWS Missoula, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
326 PM MDT FRI AUG 6 2010

...STRONG THUNDERSTORMS WITH HEAVY RAINFALL POSSIBLE ACROSS
SOUTHWEST MONTANA AND LEMHI COUNTY IN IDAHO DURING THIS EVENING...

.DISCUSSION...

TONIGHT...A VERY MOIST AND UNSTABLE ATMOSPHERE...COUPLED WITH
SOUTHWESTERLY WIND SHEAR...WILL ALLOW STRONG THUNDERSTORMS TO
DEVELOP ACROSS WESTERN MONTANA AND NORTH CENTRAL IDAHO. LARGE
HAIL...DAMAGING WINDS...AND HEAVY RAIN ARE POSSIBLE WITH SOME OF THESE
STORMS...PARTICULARLY ACROSS PORTIONS OF SOUTHWEST MONTANA.
THEREFORE A SEVERE THUNDERSTORM WATCH AS WELL AS A FLASH FLOOD
WATCH HAVE BEEN ISSUED FOR PORTIONS OF SOUTHWEST MONTANA. PLEASE
SEE WWW.WEATHER.GOV/MISSOULA FOR FURTHER INFORMATION. THESE STORMS
ARE ANTICIPATED TO MOVE EAST OF THE CONTINENTAL DIVIDE BEFORE
MIDNIGHT.

THE MAIN THUNDERSTORM THREAT WILL SHIFT SLIGHTLY SOUTH AND EAST
TOMORROW...FOCUSING MAINLY ACROSS SOUTHWEST MONTANA AND LEMHI
COUNTY IN IDAHO. THESE AREAS WILL MAINTAIN THE BEST INSTABILITY
AND MOISTURE PROFILES TO FAVOR THUNDERSTORMS. CONTINUED THREATS
WITH THESE THUNDERSTORMS WILL BE HEAVY RAIN...GUSTY WINDS AND
SMALL HAIL. A DISTURBANCE WILL MOVE THROUGH NORTHWEST MONTANA LATE
TOMORROW AFTERNOON INTO TOMORROW EVENING...PRODUCING MAINLY
SHOWERS WITH A FEW CLAPS OF THUNDER POSSIBLE. SOME WEAK
INSTABILITY WILL LINGER INTO SUNDAY...BUT THUNDERSTORMS ARE
EXPECTED TO GENERALLY BE ISOLATED AND WEAKER THAN PREVIOUS DAYS.
TEMPERATURES WILL REMAIN NEAR NORMAL FOR THIS TIME OF YEAR.

FORECAST MODELS INTRODUCE QUITE A BIT OF UNCERTAINTY EARLY NEXT
WEEK. WHILE ALL MODELS ARE GENERALLY INDICATING A TROUGH OVER THE
NORTHERN ROCKIES...LARGE DIFFERENCES IN STRENGTH OF THIS FEATURE
EXIST. THIS COULD MEAN THE DIFFERENCE BETWEEN NEAR NORMAL
TEMPERATURES AND WELL BELOW NORMAL TEMPERATURES BY THE TUESDAY TIME
FRAME AS WELL PRECIPITATION CHANCES. FOR THE TIME BEING HAVE
MAINTAINED NEAR NORMAL TEMPERATURES AND PRECIPITATION CHANCES.
HOWEVER...A FAIR AMOUNT OF UNCERTAINTY EXISTS FOR THE TIME BEING.

&&

.AVIATION...THUNDERSTORMS DEVELOPING ACROSS THE NORTHERN ROCKIES
DURING THIS AFTERNOON WILL IMPACT AVIATION THROUGH 07/0600Z. THE
HIGHEST PROBABILITY OF THUNDERSTORMS WITHIN 5NM OF TERMINALS IS
KBTM AND KSMN DURING THIS TIME. THESE STORMS HAVE THE POTENTIAL
FOR PRODUCING SMALL HAIL...GUSTY WINDS AND HEAVY RAIN THAT MAY
REDUCE VISIBILITY FOR A TIME. OTHERWISE...MENTION OF CB WILL
REMAIN FOR ALL OTHER AREA TERMINALS THROUGH THIS EVENING.
THEREAFTER...AVIATION IMPACTS WILL DECREASE SIGNIFICANTLY THROUGH
SATURDAY AFTERNOON.

&&

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

SHORT TERM...ZUMPFE
LONG TERM....PALLISTER/KITSMILLER
AVIATION...ZUMPFE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
349 PM MDT FRI AUG 6 2010

IDZ009-010-MTZ005-006-062230-
EASTERN LEMHI COUNTY-WESTERN LEMHI COUNTY-
BITTERROOT/SAPPHIRE MOUNTAINS-MISSOULA/BITTERROOT VALLEYS-
349 PM MDT FRI AUG 6 2010

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN RAVALLI AND NORTHERN
LEMHI COUNTIES UNTIL 430 PM MDT...

AT 342 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 10 MILES NORTH OF HALE GULCH EAST OF SHOUP...OR
29 MILES NORTHWEST OF SALMON...MOVING NORTH AT 20 MPH.

HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...MAINLY RURAL AREAS
OFSOUTHERN RAVALLI COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

&&

LAT...LON 4590 11438 4588 11398 4549 11400 4547 11432
TIME...MOT...LOC 2149Z 178DEG 18KT 4557 11420

ZUMPFE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
436 PM MDT FRI AUG 6 2010

MTZ007-062315-
BUTTE/BLACKFOOT REGION-
436 PM MDT FRI AUG 6 2010

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN DEER LODGE AND NORTHERN
SILVER BOW COUNTIES UNTIL 515 PM MDT...

AT 429 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR GREGSON HOT SPRINGS...OR 11 MILES WEST OF
BUTTE...MOVING NORTHEAST AT 10 MPH.

HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...BUTTE...SILVER BOW...
WALKERVILLE...RAMSAY AND NISSLER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

&&

LAT...LON 4591 11279 4606 11291 4623 11258 4621 11256
      4618 11256 4618 11250 4613 11249 4608 11245
      4603 11245 4602 11243
TIME...MOT...LOC 2236Z 241DEG 10KT 4603 11274

ZUMPFE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
445 PM MDT FRI AUG 6 2010

MTZ001-002-062345-
KOOTENAI/CABINET REGION-WEST GLACIER REGION-
445 PM MDT FRI AUG 6 2010

...SIGNIFICANT WEATHER ADVISORY FOR LINCOLN AND NORTHWESTERN SANDERS
COUNTIES UNTIL 545 PM MDT/445 PM PDT/...

AT 444 PM MDT/344 PM PDT/...DOPPLER RADAR INDICATED A LINE OF
STRONG THUNDERSTORMS EXTENDING FROM 13 MILES NORTH OF EUREKA TO
CLARK FORK...AND MOVING NORTHEAST AT 25 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER...OR THE SIZE OF DIMES...HAS
BEEN REPORTED WITH THESE STORMS...ALONG WITH HEAVY RAIN.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...LIBBY...EUREKA...
KOOTENAI FALLS AND REXFORD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT FRIDAY
EVENING/800 PM PDT FRIDAY EVENING/ FOR WEST CENTRAL MONTANA.

&&

LAT...LON 4825 11568 4813 11606 4832 11607 4901 11519
      4900 11471
TIME...MOT...LOC 2245Z 246DEG 20KT 4907 11502 4812 11623

DEROSA

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
454 PM MDT FRI AUG 6 2010

MTZ002-003-070000-
FLATHEAD/MISSION VALLEYS-WEST GLACIER REGION-
454 PM MDT FRI AUG 6 2010

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL FLATHEAD COUNTY UNTIL 600
PM MDT...

AT 453 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM WEST GLACIER TO
EVERGREEN...AND MOVING NORTHEAST AT 30 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER IS EXPECTED WITH THESE STORMS...
ALONG WITH HEAVY RAIN.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...WEST GLACIER...
APGAR...LAKE MCDONALD...LOGAN PASS...NYACK AND PINNACLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT FRIDAY
EVENING FOR WEST CENTRAL MONTANA.

&&

LAT...LON 4869 11369 4865 11373 4861 11373 4857 11352
      4847 11346 4846 11347 4840 11346 4820 11421
      4826 11446 4867 11414 4872 11371
TIME...MOT...LOC 2254Z 234DEG 24KT 4843 11397 4828 11421

DEROSA

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
520 PM MDT FRI AUG 6 2010

MTZ005-006-070015-
BITTERROOT/SAPPHIRE MOUNTAINS-MISSOULA/BITTERROOT VALLEYS-
520 PM MDT FRI AUG 6 2010

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL RAVALLI COUNTY UNTIL 615
PM MDT...

AT 512 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 10 MILES SOUTHWEST OF CONNER...OR 28 MILES SOUTH
OF HAMILTON...MOVING NORTHEAST AT 20 MPH.

HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM.

LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...CONNER AND DARBY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF THREATENING WEATHER APPROACHES YOUR AREA...GO INDOORS AND STAY
AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...MOVE TO A WELL
PROTECTED AREA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT FRIDAY
EVENING FOR WEST CENTRAL MONTANA.

&&

LAT...LON 4594 11439 4622 11399 4601 11379 4576 11428
      4585 11438
TIME...MOT...LOC 2320Z 229DEG 19KT 4589 11427

ZUMPFE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
525 PM MDT FRI AUG 06 2010

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

0256 PM     HAIL             6 E DARBY               46.02N 114.05W
08/06/2010  E1.00 INCH       RAVALLI            MT   TRAINED SPOTTER

            SPOTTER AT THE DEER MOUNTAIN LOOKOUT REPORTED DIME TO
            QUARTER SIZE HAIL AND HEAVY RAIN.

0604 PM     HAIL             19 E HAMILTON           46.25N 113.76W
08/05/2010  M1.50 INCH       RAVALLI            MT   NWS STORM SURVEY

            STORM SURVEY OF SKALKAHO PASS 15 HOURS AFTER THE STORM
            PASSED REVEALED HAIL STONES 1.33 INCH TO 1.5 INCH
            DIAMETER WITH HAIL ACCUMULATIONS OF OVER 4 INCHES.

0428 PM     HAIL             ESE WHITEFISH           48.41N 114.34W
08/06/2010  M1.25 INCH       FLATHEAD           MT   TRAINED SPOTTER

0451 PM     TSTM WND GST     8 N SALMON              45.29N 113.89W
08/06/2010  M62 MPH          LEMHI              ID   MESONET

            MEASURED BY KRILEY CREEK RAWS STATION

0436 PM     TSTM WND GST     SALMON                  45.18N 113.89W
08/06/2010  M60 MPH          LEMHI              ID   MESONET

            MEASURED BY THE SALMON RAWS STATION.

&&

KITSMILLER