Hail in Idaho, June 6, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
238 PM MDT MON JUN 6 2011

...STRONG STORMS THIS EVENING FOLLOWED BY WET CONDITIONS TUESDAY
IMPACTING AREA RIVERS AND STREAMS...

.DISCUSSION...UNSTABLE SOUTHERLY FLOW AHEAD OF AN APPROACHING
UPPER LOW IS SETTING THE STAGE FOR SCATTERED THUNDERSTORMS ACROSS
NORTH CENTRAL IDAHO AND WESTERN MONTANA THE REMAINDER OF THIS
AFTERNOON INTO THIS EVENING. THE POTENTIAL FOR SOME STORMS TO
BECOME SEVER EXISTS MAINLY FROM THE CENTRAL CLEARWATERS THROUGH
MISSOULA AND SEELEY LAKE TO POINTS SOUTH AND EAST. THERE ARE TWO
MAIN THREATS FROM THESE STORMS. THE FIRST IS LARGE HAIL...HEAVY
RAIN AND ERRATIC GUSTY WINDS FROM THE CLEARWATER MOUNTAINS THROUGH
MISSOULA AND SEELEY LAKE TO ANACONDA AND WESTERN LEMHI COUNTY.
FURTHER SOUTH AND EAST (EASTERN LEMHI COUNTY AND BUTTE/PINTLAR
REGION) DRIER AIR AT THE SURFACE WILL RESULT IN DRY MICROBURST
POTENTIAL (DAMAGING WINDS WITH GUSTS OVER 55 MPH) THIS AFTERNOON.
AS THE UPPER LOW APPROACHES AND MOISTURE INCREASES ACROSS LEMHI
COUNTY AND SOUTHWEST MONTANA...THE THREAT ACROSS SOUTHWEST MONTANA
WILL TRANSITION TO HAIL AND BRIEF HEAVY RAIN. STAY TUNED FOR A
POTENTIAL SEVERE WEATHER WATCH FOR THIS EVENING.

AFTER MIDNIGHT THROUGH TUESDAY AFTERNOON...THE UPPER LOW WILL
SWING NORTH THROUGH EASTERN IDAHO AND SOUTH CENTRAL MONTANA. A MID
LEVEL CIRCULATION OVER SOUTHWEST MONTANA IS IN A GOOD LOCATION TO
BRING WIDESPREAD HEAVY RAIN FALL TO PORTION OF NORTH CENTRAL IDAHO
AND WEST CENTRAL MONTANA UP ALONG THE CONTINENTAL DIVIDE. THIS IS
THE SAME LOCATION THAT RECEIVED AMPLE MOISTURE LATE LAST WEEK
WITH THE MAIN DIFFERENCE BEING SNOW LEVELS WILL BE QUITE A BIT
HIGHER (AROUND 10000 FEET) WHICH WILL RESULT IN RAIN ATOP OF SNOW.
THE PAST WEEKENDS VERY HOT TEMPERATURES ALLOWED UPPER LEVEL SNOW
PACK TO COMPACT AND INCREASE MOISTURE CONTENT. RAIN WILL INCREASE
THE MOISTURE CONTENT FURTHER...AND IT WILL EVENTUALLY WILL REACH
SATURATION AND THE RAIN WILL RUN OFF. THIS SCENARIO WILL RESULT IN
HYDROLOGIC CONCERNS FOR AREA RIVERS AND STREAMS. PLEASE SEE
WWW.WEATHER.GOV/MISSOULA FOR LATEST HYDROLOGIC HEADLINES.

ANOTHER PACIFIC WEATHER SYSTEM WILL MOVE IN FROM THE BRITISH
COLUMBIA COAST TUESDAY NIGHT. THIS SYSTEM IS BRINGING ANOTHER ROUND
OF AMPLE PRECIPITATION...BUT NOT AS MUCH AS TONIGHTS SYSTEM. THE
TRACK OF THIS NEXT SYSTEM WILL BRING THE MAJORITY OF THE
PRECIPITATION TO NORTHWEST MONTANA. WITH ITS ORIGIN FURTHER
NORTH...THE AIRMASS WILL BE COOLER AND SNOW LEVELS LOWER. THIS
WILL DECREASE THE RUN OFF POTENTIAL THROUGH WEDNESDAY.

WEDNESDAY NIGHT THROUGH FRIDAY...THE UPPER LOW WILL MOVE INTO
SOUTHWEST MONTANA KEEPING THE CHANCE OF PRECIPITATION HIGH. THIS
WILL ADD MORE WATER TO STREAMS AND RIVERS...KEEPING THEM RUNNING
HIGH.

ON SATURDAY...WESTERN MONTANA AND NORTH CENTRAL IDAHO WILL GET A
BRIEF BREAK BEFORE THE NEXT TROUGH OF LOW PRESSURE MOVES SOUTH OUT
OF CANADA AND KEEPS A CHANCE OF PRECIPITATION OVER THE REGION FOR
THE REST OF THE EXTENDED FORECAST PERIOD.

&&

.AVIATION...SCATTERED TO WIDESPREAD SHOWERS WILL AFFECT THE
NORTHERN ROCKIES TODAY. PLENTY OF DAYTIME HEATING AND
INSTABILITY ACROSS THE REGION WILL INTRODUCE THUNDERSTORM POTENTIAL
AT ALL TERMINALS THIS AFTERNOON INTO THIS EVENING. PERIODS OF
HEAVY RAIN AND SMALL HAIL MAY ACCOMPANY THE THUNDERSTORMS THIS
AFTERNOON...MAINLY IMPACTING KMSO...KBTM...AND KSMN UNTIL 07/03Z.
GUSTY AND ERRATIC WINDS WILL BE A FREQUENT FEATURE WITH THE
THUNDERSTORMS AFFECTING KBTM AND KSMN. MORE ISOLATED STORMS CAN BE
EXPECTED AT KGPI. BEYOND 07/03Z...THUNDERSTORM ACTIVITY SHOULD
LESSEN...ALLOWING FOR MORE PERSISTENT RAIN SHOWERS TO AFFECT THE
ENTIRE NORTHERN ROCKIES. CLOUD DECKS WILL THEN LOWER TO MVFR
LEVELS THROUGH TUESDAY.

&&

NOTE: FLOOD WATCHES...WARNINGS AND ADVISORIES WILL NOT BE LISTED BELOW.

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

SHORT TERM...MEAD
LONG TERM....KOLATA
AVIATION...ALLEGRETTO

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
453 PM MDT MON JUN 06 2011

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

0416 PM     HAIL             POWELL                  46.58N 114.72W
06/06/2011  E0.75 INCH       IDAHO              ID   TRAINED SPOTTER

&&

ZUMPFE