FXUS65 KPIH 262055
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
200 AM MST THU NOV 26 2009

.SHORT TERM...TONIGHT THROUGH SUNDAY. THE LATEST SATELLITE IMAGERY 
WAS SHOWING A FLAT UPPER RIDGE POSITIONED OVER THE DIVIDE WITH THE 
NEXT UPSTREAM SPLIT-TROUGH APPROACHING THE COAST. THE GFS/ECMWF ARE 
BOTH DEPICTING THE SPLIT WAVE MOVING INLAND LATE TONIGHT AND FRIDAY 
WITH THE LEADING EDGE OF PRECIPITATION SHIELD SPREADING INTO THE 
CNTRL MOUNTAINS FRIDAY AFTERNOON. AS THE WAVE MOVES FURTHER INLAND 
AND THROUGH THE GREAT BASIN FRIDAY NIGHT...THE NRN AND SRN SECTORS 
OF THE TROUGH WILL SPREAD FURTHER APART (SPLIT AND WEAKEN) LEAVING 
SE IDAHO BETWEEN THE TWO MAIN DYNAMICAL BRANCHES OF THE TROUGH. 
TYPICALLY WE DO NOT RECEIVE MUCH IN THE WAY OF SIGNIFICANT 
PRECIPITATION FROM SPLIT TROUGHS AND THUS THE PRECIPITATION 
POTENTIAL WILL REMAIN LOW (CHANCE MENTION) THROUGH THE PERIOD. THE 
WAVE EXITS OFF TO THE EAST MONDAY AFTERNOON AS A RIDGE AMPLIFIES 
ALONG THE PAC COAST WITH COOL AND MOSTLY DRY CONDITIONS EXPECTED FOR 
SUNDAY. HUSTON

.LONG TERM...SUNDAY NIGHT THROUGH NEXT THURSDAY.  HIGH PRESSURE WILL 
HOLD THROUGH MONDAY ACROSS EASTERN IDAHO. HAVE CONTINUED TO DRY OUT 
THE FORECAST BUT STILL LEAVING A LESS THAN 10% CHANCE ACROSS THE 
NORTHERN MOUNTAINS FOR COLLABORATION PURPOSES. AFTER THAT...12Z GFS 
AND 0Z ECMWF NOT ONLY DISAGREE WITH ONE ANOTHER BADLY THEY DIFFERENT 
SOMEWHAT FROM 24 HOURS AGO ESPECIALLY THE GFS. HAVE LEFT THE 
PREVIOUS FORECAST PRETTY MUCH INTACT WITH A BETTER CHANCE OF SNOW 
TUESDAY AND TUESDAY NIGHT...THEN DROPPING BACK TO A SLIGHT CHANCE OF 
MOUNTAIN SNOW SHOWERS BEYOND THAT. TEMPERATURES WILL AGAIN NOT GET 
TOO WARM WITH HIGHS MOSTLY STAYING IN THE 20S AND 30S. THE ONLY 
PLACES THAT MIGHT GET TO 40 OR SO WILL BE IN THE WARMER SPOTS OF THE 
MAGIC VALLEY AND SOUTHERN HIGHLANDS. KEYES
&&

.AVIATION...VFR CONDITIONS EXPECTED THROUGH TOMORROW AFTERNOON. HIGH 
CLOUDS WILL CONTINUE TO MOVE IN DURING THE PERIOD. A FEW MOUNTAINS 
SNOW SHOWERS ARE POSSIBLE LATER IN THE AFTERNOON AROUND KSUN AS 
DEEPER MOISTURE ASSOCIATED WITH THE NEXT SYSTEM ARRIVES. FOR THE 
REST OF THE HOLIDAY WEEKEND...ALL TAF SITES COULD SEE CONDITIONS 
DROPPING TO IFR WITH SOME SNOW FRIDAY NIGHT AND SATURDAY MORNING AS 
THE NEXT SYSTEM MOVES THROUGH. VFR CONDITIONS SHOULD PREVAIL FOR THE 
REST OF THE WEEKEND...ALTHOUGH PILOTS WILL NEED TO MONITOR FOR THE 
POSSIBILITY OF LOW CLOUDS/FOG SUNDAY MORNING AT VALLEY TAF SITES 
ESPECIALLY KIDA AND KPIH. KEYES
&&

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

$$