Funnel Cloud in Montana, May 30, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
905 AM MDT FRI MAY 30 2008

.UPDATE...MADE A FEW TWEAKS TO FORECAST CHANCES OF PRECIPITATION...CLOUD
COVER AND WEATHER FOR TODAY.

&&

.DISCUSSION...LOW LEVEL MOISTURE REMAINS RATHER PREVALENT THIS
MORNING ACROSS MUCH OF WESTERN MONTANA AND CENTRAL IDAHO RESULTING
IN THE FORMATION OF FOG AND/OR LOW STRATUS CLOUDS. A WEAK MID
LEVEL BOUNDARY...PARTIALLY RESPONSIBLE FOR LAST NIGHTS CONVECTION...HAS
STALLED OVER CENTRAL IDAHO AND MONTANA THIS MORNING. GIVEN THE
ABUNDANCE OF MOISTURE...LIGHT TO BRIEFLY MODERATE RAIN SHOWERS
HAVE DEVELOPED AND WILL REMAINS SCATTERED ACROSS THE AREA WITH
LITTLE ORGANIZATION THROUGH THE MORNING HOURS. PRECIPITATION
AMOUNTS GENERALLY WILL BE LIGHT AND ON THE ORDER OF ONLY A FEW
HUNDREDTHS OF AN INCH.

EXPECT CLOUD COVER TO REMAIN FAIRLY THICK THROUGH MUCH OF THE DAY
ACROSS CENTRAL IDAHO AND WESTERN MONTANA WITH REDEVELOPMENT OF
SHOWERS AND SOME THUNDERSTORMS AFTER 18Z. THE BEST CHANCES FOR
PRECIPITATION WILL BE ALONG THE DIVIDE...ACROSS CENTRAL IDAHO AND
OVER THE CENTRAL AND SOUTHERN PORTIONS OF WESTERN MONTANA. FURTHER
UPDATES ARE NOT EXPECTED TODAY.

&&

.AVIATION...PLENTY OF LOW LEVEL MOISTURE EXISTS THROUGHOUT WESTERN
MONTANA AND NORTH-CENTRAL IDAHO. CLOUDS WILL CONTINUE TO OBSCURE
MOUNTAINS AND PASSES THROUGH THE DAY. CLOUD BASES MAY RISE A BIT
THIS AFTERNOON...BUT OVERALL CONDITIONS WILL SHOW ONLY MODEST
CEILING IMPROVEMENT. SHOWER ACTIVITY WILL PICK THIS AFTERNOON AS
THE ATMOSPHERE BECOMES MORE UNSTABLE. THUNDERSTORMS WILL ALSO BE
PART OF THE AFTERNOON/EVENING FORECAST. SOUTHWEST MONTANA AND
LEMHI COUNTY WILL BE THE MOST FAVORABLE REGION FOR THUNDERSTORMS.

OVERALL CONDITIONS ARE EXPECTED TO IMPROVE AFTER DARK TONIGHT...
WITH SHOWERS DIMINISHING AND SKY CONDITIONS TRENDING TOWARD
PARTIAL CLEARING.

&&

.PREV DISCUSSION... /ISSUED 338 AM MDT FRI MAY 30 2008/

DISCUSSION...LOW LEVEL MOISTURE AND A WEAK DISTURBANCE WILL
CONTINUE TO CAUSE A FEW SHOWERS ACROSS THE NORTHERN ROCKIES
TODAY...ESPECIALLY ACROSS SOUTHWEST MONTANA AND NORTH CENTRAL
IDAHO. THE BEST CHANCE FOR THUNDERSTORM DEVELOP THIS AFTERNOON AND
EVENING APPEARS TO BE IN THE AFOREMENTIONED REGION. A WEAK RIDGE
OF HIGH PRESSURE WILL BUILD OVER THE AREA TONIGHT CAUSING THE
ATMOSPHERE TO STABILIZE. SO SHOWERS AND THUNDERSTORMS SHOULD
QUICKLY DIMINISH AFTER SUNSET. TEMPERATURES FOR TODAY AND TONIGHT
SHOULD BE NEAR SEASON NORMALS.

THE UPPER LEVEL FLOW WILL TRANSITION TO SOUTHWESTERLY ON SATURDAY.
THIS FLOW WILL ALLOW FOR AMPLE MOISTURE AND ENERGY TO MOVE INTO
THE NORTHERN ROCKIES ESPECIALLY SATURDAY NIGHT. SHOWER ACTIVITY
IS EXPECTED TO INCREASE THROUGHOUT THE NIGHT TIME HOURS. A WARM
AIRMASS WILL BE USHER INTO THE REGION UNDER THIS FLOW PATTERN SO
EXPECT TEMPERATURES FOR SATURDAY AND SATURDAY NIGHT TO BE ABOVE
SEASON NORMALS.

THE SOUTHWESTERLY FLOW WILL CONTINUE SUNDAY AHEAD OF A CLOSED UPPER
LEVEL LOW SPINNING ALONG THE WASHINGTON COAST. THIS FEATURE WILL
PUMP MOISTURE AND ENERGY INTO THE NORTHERN ROCKIES BRINGING WIDESPREAD
SHOWERS AND THE POSSIBILITY OF THUNDERSTORMS THROUGH THE DAY.
TEMPERATURES WILL COOL SIGNIFICANTLY OVER SATURDAY AS A COOLER
AIRMASS IS USHERED INTO THE REGION.

THE LOW PRESSURE SYSTEM WILL SLOWLY MEANDER THROUGH THE AREA
MONDAY CONTINUING COOLER TEMPERATURES AND SHOWER ACTIVITY. A
SHORTWAVE RIDGE WILL FOLLOW IN ITS WAKE TUESDAY...BUT WILL LEAD
ONLY TO A SHORT BREAK IN PRECIPITATION. BEYOND TUESDAY...LONG
RANGE MODELS BEGIN TO DIVERGE BUT GENERALLY AGREE ON THE
CONTINUATION OF A FAIRLY ENERGETIC FLOW WITH WEATHER DISTURBANCES
BRINGING PERIODICALLY SHOWERY PERIODS. TEMPERATURES ARE EXPECTED
TO REMAIN AT OR SLIGHTLY BELOW NORMAL THROUGH THIS TIME FRAME.

&&

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

SHORT TERM...DICKERSON
LONG TERM....VIA
AVIATION...MSJ