FXUS65 KPIH 272127
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
227 PM MST FRI NOV 27 2009

.SHORT TERM...TONIGHT THROUGH MONDAY. TROUGH/UPPER LOW CONTINUING
TO MOVE INLAND PER WV IMAGERY. SHORTWAVE UNDERGOING SPLIT WITH
STRONGER UPPER LOW PULLING SOUTHEAST THROUGH CALIFORNIA THIS
AFTERNOON AND NORTHERN SHORTWAVE SKIPPING THROUGH PANHANDLE. BULK
OF MOISTURE ASSOCIATED WITH TROUGH PULLING SOUTH WITH MAIN LOBE OF
TROUGH. RADAR MOSAIC SHOWING WEAK PRECIP IN WESTERN IDAHO WITH SFC
OBS INDICATING LITTLE PRECIP MAKING IT INTO FCST AREA AT THIS
TIME. HAVE OPTED TO KEEP LIKELY POPS OVER HIGHER TERRAIN GIVEN
DYNAMICS OF THE SYSTEM BUT MOISTURE RAPIDLY BECOMING A QUESTION
UNDER THE SPLIT. VALLEY POPS WILL REMAIN LOW THROUGH TONIGHT
THOUGH ISOLATED SNOW SHOWERS NOT OUT OF THE QUESTION WITH VERY
LIGHT ACCUMULATIONS OVERNIGHT. AXIS OF NORTHERN STREAM TROUGH
PASSES THROUGH FCST AREA LATE TONIGHT/EARLY SATURDAY MORNING WITH
DEEP UPPER LOW CLOSED OFF OVER SOUTHERN CALIFORNIA BY THAT TIME.
MUCH OF THE PRECIPITATION SHOULD BE OVER WITH LINGERING ISOLATED
SHOWERS OVER HIGHER TERRAIN ALONG WYOMING BORDER. FOR THE
REMAINDER OF THE WEEKEND INTO MONDAY...UPPER RIDGE BUILDS INTO
PACNW FOR RETURN TO DRY AND COOL CONDITIONS. DMH

.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE GFS AND ECMWF STILL AT 
GREAT ODDS WITH EACH OTHER. SINCE THE ECMWF HAS BEEN THE MORE 
CONSISTENT MODEL...WE HAVE CONTINUED TO TREND THE FORECAST IN THAT 
DIRECTION. THE NEXT WAVE WILL CONTINUE TO DROP ACROSS AND THROUGH 
EASTERN IDAHO LATER TUESDAY AND WEDNESDAY. THIS WILL BE BRING A SHOT 
OF SNOW FOR THE MOUNTAINS AND A LOW CHANCE ACROSS THE SOUTHERN AND 
EASTERN FRINGES OF THE SNAKE PLAIN. AFTER THAT...NORTHERLY FLOW WILL 
TAKE OVER WITH COLDER AIR TAKING HOLD ACROSS EASTERN AREAS WHERE 
COLD AIR WOULD HAVE A BETTER CHANCE OF MAKING IT OVER/THROUGH THE 
DIVIDE. HAVE LEFT THE IDEA OF A VERY SLIGHT CHANCE OF SNOW ON THE 
HIGHER PEAKS. HIGHS WILL REMAIN IN THE 20S AND 30S...WITH AREAS 
FARTHEST FROM ANY COLD AIR INTRUSION SEEING TEMPERATURES CLOSER TO 
40 IN THE AFTERNOON.  KEYES 

&&

.AVIATION...A STORM SYSTEM WILL WORK ACROSS EASTERN IDAHO THROUGH 
SATURDAY. VFR CONDITIONS ARE EXPECTED SAVE FOR A 6 HOUR OR SO WINDOW 
TONIGHT AND SATURDAY MORNING FOR TAF SITES ACROSS EASTERN IDAHO. 
DURING THIS WINDOW SOME LIGHT SNOW...STRATUS AND/OR FOG IS FORECAST. 
KSUN SHOULD SEE THAT WINDOW DURING THE EVENING AND EARLY OVERNIGHT 
HOURS. BY 8Z TO 9Z TONIGHT...THE WINDOW SHIFTS TO KBYI...KPIH AND 
KIDA. WEATHER CONDITIONS SHOULD DROP TO MVFR/HIGH END IFR DURING 
THIS PERIOD. FOR THE WEEKEND...VFR CONDITIONS WILL PREVAIL WITH A 
SLIGHT CHANCE OF SNOW FOR THE MOUNTAINS REMAINING. AT THIS TIME...WE 
DO NOT HAVE FOG OR STRATUS IN MIND FOR THE VALLEY TAF SITES. 
HOWEVER...FORECAST DATA DOES SUGGEST THAT ENOUGH MOISTURE MIGHT POOL 
IN THE VALLEY FOR THAT TO HAPPEN.  STAY TUNED.  KEYES

&&

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

$$