FXUS65 KPIH 252051
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
200 PM MST WED NOV 25 2009

.SHORT TERM...TONIGHT THROUGH SATURDAY. LATEST SATELLITE IMAGERY 
SHOWING UPPER RIDGE OVER THE REGION WITH RELATIVELY DRY CONDITIONS. 
RIDGE WILL CONTINUE TO DOMINATE TONIGHT AND THURSDAY WITH AREAS OF 
VALLEY FOG RETURNING TO MOUNTAINS AND SNAKE RIVER PLAIN TONIGHT AS 
PARTICULATE MATTER CONTINUES TO BUILD UP UNDER INVERSION. RIDGE 
BREAKS DOWN THURSDAY NIGHT/FRIDAY AS NEXT PACIFIC TROUGH MOVES 
INLAND. LATEST GFS MAKING A DEFINITE MOVE TOWARD THE ECMWF SOLUTION 
WITH A STRONG INDICATION THAT THE INCOMING TROUGH WILL UNDERGO A 
SPLIT AS IT MOVES INTO/THROUGH THE GREAT BASIN FRIDAY/FRIDAY NIGHT. 
THUS HAVE SCALED BACK PRECIPITATION POTENTIAL IN RESPONSE. SPLIT 
WAVE EXITS THE REGION SATURDAY AS SECONDARY ENERGY DIVES SOUTH 
THROUGH THE PANHANDLE WHILE LONG-WAVE RIDGE HOLDS FIRM ALONG THE 
COAST. THUS HAVE CONTINUED CHANCE/SLIGHT CHANCE POPS IN DIRTY 
(MOIST) NW FLOW FOR SATURDAY. RIDGES SHOWED SOME WARMING DURING PAST 
24HRS AND EXPECT THE SAME TONIGHT/THURSDAY AS VALLEY INVERSIONS KEEP 
COLDER AIR TRAPPED IN VALLEYS. HOPEFULLY WE MIX OUT THURSDAY 
NIGHT/FRIDAY AS FLOW INCREASES FROM SW AND SURFACE AND UPPER TROUGH 
PROGRESS THROUGH THE AREA. HUSTON

.LONG TERM...SATURDAY NIGHT THROUGH NEXT WEDNESDAY. BOTH THE GFS AND 
ECMWF SHOW A QUICK MOVING SECONDARY WAVE MOVING THROUGH EASTERN 
IDAHO SATURDAY NIGHT...DROPPING SOUTH INTO THE CLOSED LOW ACROSS THE 
DESERT SOUTHWEST/NORTHERN MEXICO. HAVE KEPT WITH HIGHEST POPS IN THE 
CENTRAL MOUNTAINS AND SOUTHERN/EASTERN HIGHLANDS AS WELL AS THE 
SOUTHERN/EASTERN FRINGES OF THE SNAKE PLAIN. THIS KEEPS IN LINE WITH 
AREAS THAT TYPICALLY SEE SOME ENHANCEMENT IN PRECIP CHANCES IN NW 
UPSLOPE FLOW. THE MODELS CONTINUE TO BRING A RIDGE IN AND DRY OUT 
THE AREA. WE HAVE CONTINUED TO TREND THE FORECAST IN THAT DIRECTION 
AND LEFT IN VERY LOW POPS ACROSS THE NORTHERN MOUNTAIN PEAKS. BOTH 
MODELS THEN BRING ANOTHER DIGGING WAVE ACROSS EASTERN IDAHO TUESDAY 
AND NORTHERLY FLOW ON WEDNESDAY. HAVE AGAIN TRENDED TOWARD A LITTLE 
BETTER CHANCE OF SNOW ON TUESDAY ACROSS THE AREA...NEAR CLIMO 
NUMBERS...THEN TRIMMED POPS BACK TO SLIGHT CHANCE IN THE CENTRAL 
MOUNTAINS AND SLIGHT CHC/LOW CHANCE IN THE EASTERN MOUNTAINS. 
TEMPERATURES WILL NOT WARM TOO MUCH WITH MOSTLY 20S AND 30S FOR 
HIGHS DURING THE PERIOD. IT DOES APPEAR SOME OF TYPICALLY WARMER 
VALLEYS DOWN SOUTH WILL BE AROUND 40 ON MONDAY AND TUESDAY. KEYES 
&&

.AVIATION...VFR CONDITIONS ARE FORECAST DURING THE NEXT 24 HOURS. 
THE ONLY CAVEAT IS POSSIBLE FOG AT KIDA AND/OR KPIH. DUE TO THE 
FORECAST OF VERY PATCHY FOG...CHOSE NOT TO INCLUDE IT IN TAFS AT 
THIS TIME. THIS POSSIBILITY WILL NEED TO BE MONITORED CLOSELY. KEYES 
&&

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

$$