HAMweather.com Area Forecast Discussion for County Warning Area MSO

Thu, 16 Feb 2012 12:09:41 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
323 AM MST THU FEB 16 2012

.DISCUSSION...

OVERNIGHT LOW CLOUDS REMAINED OVER MUCH OF NORTHWESTERN MONTANA 
AND THE NORTHERN CLEARWATER MOUNTAINS. TODAY CLOUDS WILL 
INCREASE DUE TO A WEAK SYSTEM APPROACHING FROM WASHINGTON. SNOW 
SHOWERS WILL INCREASE THROUGH THE DAY AND MAINLY AFFECT 
NORTHWESTERN MONTANA UNTIL THIS EVENING WHEN SHOWERS SPREAD ACROSS
THE WHOLE REGION.

WITH DAYTIME HIGHS FORECAST IN THE MID 30S TO NEAR 40...SOME
VALLEYS WILL BRIEFLY SEE RAIN OR A RAIN SNOW MIX. RE-FREEZING MAY
CAUSE ICY CONDITIONS...ESPECIALLY DURING THE EVENING HOURS. SNOW
ACCUMULATIONS WILL BE LESS THAN HALF AN INCH IN THE VALLEYS AND 2
TO 4 INCHES IN THE MOUNTAINS...SO MOUNTAIN PASSES WILL ALSO BE
SLICK. FRIDAY MORNING CONDITIONS WILL IMPROVE WITH A BRIEF PERIOD
OF HIGH PRESSURE BETWEEN SYSTEMS. 

A TROUGH IS EXPECTED TO BRING WEATHER IMPACTS TO THE REGION FROM
FRIDAY NIGHT THROUGH SUNDAY. THE MAIN SNOW WITH THE SYSTEM IS
FORECAST TO OCCUR WITH A FRONTAL FEATURE FRIDAY NIGHT THROUGH
SATURDAY MORNING. THE HIGH TERRAIN INCLUDING MOUNTAIN PASSES ARE
EXPECTED TO RECEIVE 3 TO 7 INCHES OF SNOW DURING THIS TIME-FRAME.
MODEL GUIDANCE AGREE THAT THERE WILL BE A SHORT PERIOD OF TIME
SATURDAY MORNING WITH MODERATE TO HEAVY SNOWFALL IN THE HIGH
TERRAIN...THAT COULD RESULT IN A COUPLE OF OF HOURS OF POOR
DRIVING CONDITIONS. MOST VALLEY LOCATIONS ARE NOT CURRENTLY
EXPECTED TO RECEIVE AS MUCH SNOWFALL WITH AMOUNTS LESS THAN 2
INCHES. COOLER AIR ALOFT WILL MOVE IN BEHIND THE COLD FRONT AND
THE RESULTANT UNSTABLE ATMOSPHERE WILL PROMOTE SNOW SHOWERS
THROUGH SUNDAY.
 
BRIEF HIGH PRESSURE IS POSSIBLE ON MONDAY BEFORE THE REGION
TRANSITIONS INTO AN ACTIVE NORTHWESTERLY FLOW. TEMPERATURES ARE
ALSO EXPECTED TO WARM TUESDAY AND WEDNESDAY WITH MOUNTAIN SNOW AND
VALLEY RAIN. A STRONGER JET THAN WE HAVE SEEN LATELY WILL ALSO
PASS OVER THE REGION WITH BREEZY CONDITIONS THROUGH THURSDAY.

.AVIATION...SOME AREAS OF LOW CLOUD REMAIN OVER THE REGION THIS
MORNING...MAINLY AFFECTING KGPI...LIBBY AND EUREKA. CEILINGS AT
THESE LOCATIONS WILL LIKELY NOT LIFT SIGNIFICANTLY TODAY DUE TO
AMPLE LOW LEVEL MOISTURE AND INCREASING HIGH CLOUDS. SNOW SHOWERS
WILL START TODAY IN NORTHWEST MONTANA AND SPREAD TO WESTERN
MONTANA AND CENTRAL IDAHO THIS EVENING CAUSING REDUCED
VISIBILITY...LOWERING CEILINGS...AND MOUNTAIN OBSCURATIONS. 

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