911 
FXUS65 KMSO 252054
AFDMSO

WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
200 PM MST SAT DEC 25 1999

SURFACE HIGH PRESSURE AND RIDGE ALOFT TO DOMINATE THROUGH THE
PERIOD...SO WILL LET PERSISTENCE FORECAST RIDE ON WITH CONTINUED
WIDESPREAD STRATUS/FOG. TEMPS IN THE LOWER VALLEYS ARE CLOSE TO
EQUILIBRIUM IN STAGNANT AIRMASS...THUS WILL KEEP THOSE HIGHS AND LOWS
JUST A COUPLE DEGREES FROM EACH OTHER. SIGLER

EXTENDED...MODELS HINTING AT SLOWLY BREAKING DOWN THE RIDGE DURING
THE PERIOD. HOWEVER...UNTIL A SIGNIFICANT SHORT WAVE MIGRATES THROUGH
THE AREA TO HELP MIX THE INVERSION...VALLEY LOW CLOUDS AND FOG WILL
CONTINUE. WILL ADJUST THE SKY COVER ABOVE THE STRATUS/FOG TO PARTLY
CLOUDY. PERSISTENCE RULES JOHNSON