FXUS65 KBOI 261047
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
347 AM MST SAT DEC 26 2009

.SHORT TERM...TODAY THROUGH SUNDAY...STRATUS HAS CONTINUED TO WORK
WESTWARD INTO NORTH CENTRAL MALHEUR COUNTY/JORDAN VALLEY...WEISER
RIVER BASIN AND BAKER VALLEY AS WELL AS TO DREWSEY AND NEW
PRINCETON BASED ON SATELLITE SPLIT WINDOW /11-3.9MICRON/ IMAGERY.
IT CONTINUED ACROSS THE TREASURE AND MAGIC VALLEYS. LOCALLY SLICK
CONDITIONS ARE EXPECTED WITH DENSE FOG WITH SUB-FREEZING
TEMPERATURES IN THE MAGIC VALLEY THIS MORNING. UPPER LEVEL SHEAR
AXIS SEEN ON WATER VAPOR TO THE ORE-IDA BORDER LOOKS TO PUSH WEST
THROUGH NE OREGON THIS MORNING HELPING TO DRAG STRATUS TO
BAKER/BURNS BEFORE THE SHEAR AXIS BECOMES NEARLY STATIONARY NW-SE
ACROSS OREGON TONIGHT AND SUNDAY. SO THE STRATUS LOOKS TO REMAIN
SOLIDLY ACROSS THE LOWER TREASURE VALLEY THROUGH SUNDAY. CUT OFF
UPPER HIGH OVER SW CANADA AND DEVELOPING UPPER LOW OFF THE COAST
RESULT IN DRY WEATHER UNTIL SUNDAY WHEN A SLIGHT CHANCE OF SNOW
NUDGES INTO HARNEY COUNTY DUE TO THE LOW OFFSHORE. ANY QPF WILL BE
VERY LIGHT AS SPLIT FLOW REMAINS OVER SE OREGON AND SW IDAHO. HIGH
PRESSURE CENTERED TO OUR EAST AND LOWER PRESSURE OFFSHORE WILL
BRING LIGHT NE TO SE WINDS ACROSS THE REGION THE NEXT TWO DAYS
EXCEPT CHANNELED AREAS SUCH AS JEROME WHERE 10-20 MPH NE WINDS
ARE EXPECTED AT TIMES.

STAGNANT CONDITIONS IN OREGON MAY IMPROVE SOME THIS AFTERNOON AS
EAST WINDS AT THE SURFACE INCREASE SLIGHTLY THE NEXT TWO DAYS.
THIS INCREASE IN WIND IS IN RESPONSE TO THE OFFSHORE LOW MOVING
CLOSER WHILE HIGH PRESSURE SURFACE AND ALOFT CONTINUE FROM SW
CANADA THROUGH THE NORTHERN ROCKIES...INCREASING THE GRADIENT OVER
OREGON. 

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...WITH THE FLOW SPLIT OFF 
THE COAST AND MOST OF THE ENERGY WELL SOUTH OF US WE ARE KEEPING 
POPS LOW THROUGH MONDAY NIGHT. AS A RIDGE BEGINS TO BUILD OFFSHORE 
...MOIST NORTHWEST FLOW ALOFT WORKS ITS WAY FAR ENOUGH NORTH TUESDAY 
AND WEDNESDAY TO RAISE POPS TO A LITTLE ABOVE CLIMATOLOGY. THE GFS40 
AND ITS ENSEMBLE MEAN...AND THE CANADIAN...MOVE THE RIDGE INLAND 
THURSDAY AND FRIDAY. ENOUGH FLOW CONTINUES THROUGH THE RIDGE TO KEEP 
POPS NEAR CLIMATOLOGY. THE ECMWF WANTS TO BRING A SHORTWAVE TROUGH 
OVER THE PACIFIC NORTHWEST ON FRIDAY...AND THIS WOULD ALSO SUPPORT 
POPS AT LEAST NEAR CLIMATOLOGY. MODEL SOUNDINGS SHOW A STABLE 
BOUNDARY LAYER WITH A SURFACE BASED INVERSION THROUGH THE PERIOD. SO 
WE ARE KEEPING TEMPERATURES A FEW DEGREES BELOW NORMAL THROUGH 
THURSDAY...THEN NEAR NORMAL FRIDAY.
 
&&

.AVIATION...WIDESPREAD MVFR STRATUS COVERS THE SNAKE RIVER VALLEY 
AND ADJACENT LOWER ELEVATIONS...INCLUDING THE NORTHERN HALF OF 
MALHEUR COUNTY AND BAKER COUNTY. THIS AREA HAS BEEN EXPANDING WEST 
AND NORTH AND IS EXPECTED TO PERSIST AT LEAST UNTIL MID AFTERNOON... 
BUT LIKELY CONTINUE THROUGH TONIGHT. PATCHY VLIFR STRATUS AND FOG IN 
THE MAGIC VALLEY WILL IMPROVE TO MVFR BY 18Z. OTHERWISE VFR 
CONDITIONS WILL PREVAIL WITH MOSTLY CLEAR SKIES. SURFACE WINDS WILL 
BE LIGHT. WINDS ALOFT WILL BE LIGHT TO MODERATE FROM THE EAST. 

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...AIR STAGNATION ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ061-
     ORZ062.
&&

$$

WEATHER.GOV/BOISE

SHORT TERM...VM
LONG TERM....JT
AVIATION.....JT