FXUS65 KPIH 260248
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
748 PM MST FRI DEC 25 2009

.UPDATE...WITH WIDESPREAD FOG AND STRATUS OVER THE SNAKE RIVER
PLAIN AND EASTERN MAGIC VALLEY...DEWPOINTS ARE REMAINING FAIRLY
HIGH AND DO NOT BELIEVE THAT LOWS WILL GET AS COLD AS CURRENT
PREDICTIONS. THERE IS A FEATURE MOVING IN FROM THE NORTHEAST THAT
MAY HELP SCATTER OUT THE LOW LYING CLOUDINESS...BUT IT IS BRINGING
CLOUDS OF ITS OWN. WILL WARM TEMPERATURES SOME IN THE VALLEY
ZONES. HAVE SEEN NO SIGNS OF DENSE FOG...BUT THERE IS SOME FOG IN
THE DRAINAGES SOUTH OF THE SNAKE RIVER THAT JOINT THE SNAKE RIVER
BASIN. WILL ADJUST TONIGHTS LOWS AND PUT IN MORE FOG IN THE MORE
LIKELY LOCATIONS.  MESSICK

&&

.PREV DISCUSSION... /ISSUED 246 PM MST FRI DEC 25 2009/ 

SHORT TERM...THE 12Z NAM12 SURFACE AND BOUNDARY LAYER WINDS/RH
FIELDS SUPPORT NORTHEAST WINDS AND DOWN VALLEY MOVEMENT AND
THINNING OF STRATUS IN THE IDAHO FALLS...POSSIBLY THE POCATELLO AREA
TONIGHT BUT NOT UNTIL CLOSE TO MORNING. ADJUST FOR COLDER
TEMPERATURES SATURDAY MORNING. OTHERWISE...SOME ADDITIONAL CLOUD
COVER ROTATING AROUND THE MID WEST LOW ACROSS THE BORDER INTO
IDAHO AND WILL KEEP A SLIGHT CHANCE OF SNOW OVER THE HIGHER
TERRAIN FOR THAT TONIGHT. LITTLE ELSE HAPPENS UNTIL MONDAY NIGHT
WHEN SOME MOISTURE OFF THE PACIFIC BEGINS TO SLIP UNDER THE
WESTERN CANADA HIGH PRESSURE RIDGE. GFS HAS THE SOUTHERN BRANCH OF
THE JET MOVING PRETTY FAR SOUTH TOWARDS BAJA SO LOTS OF
UNCERTAINTY. RS

LONG TERM...MONDAY NIGHT THROUGH FRIDAY.  MODELS STILL HAVING 
DIFFICULTIES COMING TO A CONSENSUS IN TRANSITIONING THE GREAT BASIN 
INTO MORE WEST-NORTHWESTERLY FLOW AROUND MIDWEEK. WHILE MODEL TIMING 
AND POSITIONING OF SEVERAL WAVES MOVING INTO THE AREA BEYOND TUESDAY 
IS STILL A MYSTERY...THESE WAVES GENERALLY APPEAR TO BE ON THE 
WEAKER SIDE OF THINGS.  THEREFORE HAVE MADE LITTLE CHANGE OTHER THAN 
TO UP PRECIPITATION CHANCES JUST SLIGHTLY IN THE SNAKE RIVER PLAIN.  
TEMPERATURES OVERALL STAY BELOW NORMALS THROUGH TUESDAY AND MODERATE 
TO NORMAL FOR THE LATER HALF OF THE PERIOD.

AVIATION...LOW STRATUS AND AREAS OF FOG ARE EXPECTED TO HANG AROUND 
THE SNAKE PLAIN THIS AFTERNOON THROUGH SATURDAY MORNING. LOOK FOR AT 
LEAST MVFR CONDITIONS THIS EVENING AND IFR OVERNIGHT. MODELS 
INDICATE THAT THE STRATUS MAY FURTHER THIN SATURDAY AFTERNOON... 
PARTICULARLY IN THE KBYI AND KPIH AREAS. 

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$