FXUS65 KPIH 290312
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
812 PM MST SAT NOV 28 2009

.UPDATE...HAVE MADE A MINOR UPDATE TO GRIDS FOR SATELLITE TRENDS.
FOG/IR SAT IMAGERY SHOW LARGE PATCH OF STRATUS/LOW CLOUDS OVER
SIGNIFICANT PORTION OF EASTERN MAGIC VALLEY EXTENDING SOUTH INTO
VALLEYS OF SOUTHERN HIGHLANDS...AND NOW BEGINNING TO PUSH UP SNAKE
RIVER CHANNEL ALONG INTERSTATES 86 AND 15. AREA WEBCAM IMAGERY
AND SFC OBS INDICATE ONLY LIGHT VISIBILITY RESTRICTIONS SO WILL
HOLD OFF ON A DENSE FOG ADVISORY UNLESS CONDITIONS WORSEN. THUS
ONLY GRID ADJUSTMENTS ARE TO SPREAD COVERAGE OF PATCHY FOG AND
STRATUS THROUGH VALLEYS FOR THE REST OF OVERNIGHT. DMH

&&

.PREV DISCUSSION... /ISSUED 148 PM MST SAT NOV 28 2009/ 

SHORT TERM...TONIGHT THROUGH MONDAY NIGHT.

CLOUD BANK IN UPPER MAGIC VALLEY HAS BEEN SLOW TO DISSIPATE THIS
AFTERNOON AND HAVE ISSUED NOWCAST TO DISCUSS THIS. WITH LEFT OVER
MOISTURE AND CLEAR SKIES EXPECT SOME PATCHY LOW CLOUDS AND FOG TO
REDEVELOP IN THE SNAKE RIVER VALLEY AND ALSO IN THE CACHE AND BEAR
LAKE VALLEYS OVERNIGHT. OTHERWISE...RIDGE OF HIGH PRESSURE WILL
CONTINUE TO BUILD THROUGH THE REST OF THE WEEK. ANOTHER ROUND OF
PATCHY FOG IS EXPECTED MONDAY MORNING. VLP

LONG TERM...TUESDAY THROUGH SATURDAY. 

SHORT WAVE EXPECTED TO DROP SOUTH ACROSS THE NORTHERN ROCKIES ON
TUESDAY...PASSING PRIMARILY TO THE NORTH AND EAST OF THE FORECAST
AREA. LIMITED MOISTURE WILL SPILL INTO THE CENTRAL MOUNTAINS AND
ALONG THE WYOMING BORDER...OTHERWISE EXPECT COOL AND DRY NORTHWEST
FLOW INTO TUESDAY NIGHT. BEHIND THIS SYSTEM...A RIDGE REBUILDS
ALONG THE WEST COAST THROUGH WEDNESDAY NIGHT. MODELS REALLY START
TO DIVERGE ON THURSDAY WITH THE ECMWF MOVING A FEW WEAK BUT
PROGRESSIVE SYSTEMS THROUGH THE REGION THURSDAY AND FRIDAY WHILE
THE GFS DIGS A SLOWER AND DEEPER TROUGH INTO THE GREAT BASIN
THURSDAY NIGHT THROUGH SATURDAY. FOR NOW WILL LEAVE FORECAST AS
IS...CLOSER TO THE ECMWF SOLUTION...WITH LIGHT POPS IN THE HIGHER
ELEVATIONS FOR THE LATER HALF OF THE WEEK.

AVIATION...LOW STRATUS AND FOG PERSISTING THIS AFTERNOON IN THE 
LOWER SNAKE PLAIN...NEAR KBYI AND EXTENDING TO KSUN.  EXPECT THIS 
LAYER TO CONTINUE TO SHRINK THROUGH THIS EVENING...THEN REBUILD 
THROUGHOUT THE SNAKE PLAIN (INCLUDING KBYI...KIDA...AND KPIH) AFTER 
SUNSET.  KSUN WILL SEE FOG/STRATUS MOVE BACK OUT OF THE AREA AFTER 
03Z AS WINDS TURN MORE NORTHERLY.  STRATUS AND FOG IS EXPECTED TO 
DIMINISH BY 18Z SUNDAY.

&&

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

$$