FXUS65 KBOI 281035
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
335 AM MST SAT NOV 28 2009

.SHORT TERM...TODAY THROUGH SUNDAY...PATCHY DENSE FOG IN SOUTH
CENTRAL IDAHO WITH TEMPERATURES CLOSE TO OR BELOW FREEZING IS
EXPECTED TO LIFT EARLY THIS MORNING. WEST WINDS AROUND 13 MPH
ACCOMPANIED THIS FOG. THAT FOG WAS LIKELY THE RESULT OF
COOLING/CONDENSATION WITH THE FRONT AS IT WAS ACCOMPANIED BY WSW WINDS
AROUND 13 MPH. WINDS AROUND 15 MPH...GUSTS AROUND 30 MPH IN
ONTARIO OREGON...INHIBITED RADIATION FOG MOST OTHER PLACES IN
SPITE OF RAIN AND SNOW FRIDAY. TONIGHT WILL BE A DIFFERENT STORY.
BUT FIRST TODAY...SURFACE HIGH CENTER BUILDING INTO OREGON/CENTRAL
IDAHO WILL KEEP NW-SE SFC PRESSURE GRADIENT AND SOME WIND ACROSS
THE REGION WITH MOSTLY SUNNY SKIES. THIS RESULTS IN TEMPERATURES
CLOSE TO MOS. ALOFT A FOLD-OVER RIDGE WITH A DEVELOPING SUBSIDENCE
INVERSION TODAY NARROWS ACROSS THE AREA TONIGHT ALLOWING SOME HIGH
CLOUDS FAR NORTH. THE SURFACE HIGH CENTER EXPANDS THROUGH THE
REGION FOR LIGHT WINDS AND COLD TEMPS. ENOUGH MOISTURE IS EXPECTED
TO BE AVAILABLE FOR AREAS OF FOG /AND STRATUS MAINLY KJER-FAFI1/
TO DEVELOP LATE TONIGHT AND PERSIST INTO SUNDAY MORNING. EXPANSIVE
HIGH REMAINS OVER THE AREA SUNDAY ...THO CENTERED IN CENTRAL IDAHO
MOUNTAINS...FOR VALLEY TEMPERATURES BELOW MOS. A COUPLE OF DAYS OF
STAGNANT CONDITIONS ARE LIKELY STARTING SUNDAY.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...INVERSION IN PLACE MONDAY 
WITH MORE FOG/STRATUS IN VALLEYS MONDAY MORNING. MODELS ARE HINTING 
TOWARD A MORE NEWD TRACK FOR THE TROUGH ON TUESDAY. EFFECT WOULD BE 
LOWER POPS AND TEMPS OVER WEST CENTRAL AND BOISE MTNS AND GREATER 
CHANCE THAT INVERSION IN THE LOWER VALLEYS REMAINS INTACT. STILL 
ENOUGH UNCERTAINTY TO KEEP FOG AND STRATUS OUT OF FORECAST FOR 
TUESDAY AT THIS POINT. RIDGE AXIS RESETS ALONG THE PAC NW COAST FOR 
WED-FRI KEEPING FORECAST AREA IN A DRY NW FLOW ALOFT. WEAK INVERSION 
REMAINS IN PLACE KEEPING VALLEY TEMPS NEAR NORMAL. NEXT CHANCE FOR 
PRECIP WOULD BE FRI/SAT...THOUGH WITH N-NW SOURCE NO SIGNS OF 
TAPPING INTO ANY DEEP MOISTURE WHICH WILL LIMIT PRECIP AMOUNTS.

&&

.AVIATION...IFR-VLIFR CONDITIONS OVER THE WESTERN MAGIC VALLEY  
IMPROVE TO VFR BY 17Z THIS MORNING. VFR CONDITIONS WILL LAST UNTIL 
AT LEAST 03Z SUNDAY MORNING WITH IFR IN FOG/STRATUS DEVELOPING 
ACROSS VALLEYS AFTER 03Z. HIGH CONFIDENCE THAT KBOI WILL SEE IFR 
CONDITIONS DEVELOP AFTER 06Z SUNDAY MORNING. WITH LIGHT W WINDS 
EXPECT SOURCE OF IFR TO BE FOG /NOT STRATUS/ WHICH COULD BRING 
LIFR-VLIFR CONDITIONS TO KBOI AND OTHER LOWER TREASURE VALLEY 
AIRPORTS SUNDAY MORNING.   

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&

$$

WEATHER.GOV/BOISE

SHORT TERM...VM
LONG TERM....DG
AVIATION.....DG