FXUS65 KMSO 291116
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
416 AM MST SUN NOV 29 2009
.DISCUSSION...A HIGH PRESSURE RIDGE OVER THE WEST COAST WILL
INCREASE OVER THE NORTHERN ROCKIES. THERE IS QUITE A BIT OF
CLOUDS ACROSS MUCH OF WESTERN MONTANA THIS MORNING AND THESE
CLOUDS ARE EXPECTED TO LINGER ACROSS THE REGION THROUGH LATE THIS
AFTERNOON AND EVENING. MODELS INDICATE SOME LIFT ACROSS THE
MOUNTAINS IN NORTHWEST MONTANA AND SLOWLY PROGRESSING SOUTHWARD
THROUGH THE REGION...THOUGH ONLY LIGHT SNOW WITH SOME LOCAL
MOUNTAIN ACCUMULATIONS OF UP TO 2 INCHES OF SNOW AT HIGHER ELEVATIONS.
MONDAY NIGHT AND MORNING...THE RIDGE OF HIGH PRESSURE ESTABLISHES
ITSELF OVER THE REGION. THE MAIN IMPACT FROM THIS RIDGE IS
EXPECTED TO BE LOW CLOUDS AND FOG ACROSS THE VALLEYS BY EARLY
MORNING AS SKIES ARE EXPECTED TO CLEAR OUT.
TUESDAY AND TUESDAY NIGHT...THE RIDGE OVER THE REGION WILL BREAK
DOWN QUICKLY DURING THE EVENING. MODELS ARE INDICATING A CHANGE TO MORE
OF A NORTHWESTERLY FLOW WITH A VORT MAX PASSING ALONG THE
CONTINENTAL DIVIDE. THIS NORTHWESTERLY FLOW IS EXPECTED TO PREVENT
VALLEY FOG FROM REDEVELOPING OVERNIGHT DUE TO AN INCREASED MIXING
OF THE ATMOSPHERE AND MOSTLY CLOUDY SKIES.
WEDNESDAY THROUGH SATURDAY...CONFIDENCE REMAINS VERY LOW THROUGH
THIS PERIOD...MODELS ARE ALL OVER THE PLACE...WITH LITTLE
CONSISTENCY EVEN BETWEEN RUNS OF THE SAME MODEL. WHAT THE MODELS
DO SOMEWHAT AGREE ON IS A RIDGE OVER THE REGION WEDNESDAY INTO
THURSDAY. A DISTURBANCE MOVES ACROSS WESTERN MONTANA THURSDAY AND
FRIDAY...WITH A RIDGE BUILDING OFF OF THE PACIFIC COAST FOR THE
WEEKEND. WHAT THE MODELS DO NOT AGREE ON IS THE TIMING...PATH AND
STRENGTH OF THE DISTURBANCE. THERE IS ALSO LITTLE AGREEMENT OF
WHERE THE RIDGE WILL BUILD OFF OF THE PACIFIC COAST. WITH THESE
DIFFERENCES IN MIND...WILL INCREASE POPS TOWARD CLIMO AND BRING
TEMPERATURES MORE IN LINE WITH CLIMO.
&&
.AVIATION...NORTHWEST FLOW TODAY WILL PRODUCE SOME MAINLY
OROGRAPHIC SNOW SHOWERS. SOME OF THE HIGHER MOUNTAINS AND PASSES
COULD BE OBSCURED AT TIMES.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
ID...NONE.
&&
$$
SHORT TERM...RPN
LONG TERM....KOLATA
AVIATION...KOLATA
