FXUS65 KPIH 241020
AFDPIH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
320 AM MST THU DEC 24 2009
.SHORT TERM...TODAY THROUGH SUNDAY.
WIDESPREAD STRATUS STILL PERSISTING ACROSS SNAKE RIVER PLAIN AND
EASTERN HIGHLANDS THIS MORNING. THAT IS BIG FORECAST PROBLEM AS
PRESENCE GREATLY INCREASING LOW TEMPERATURES IN SNAKE PLAIN
OVERNIGHT. AT THIS POINT LIMITING FOG FORMATION AS WELL AND REMOVED
FROM LOWER SNAKE PLAIN THIS MORNING. SOME FOG HAS MADE IT INTO
IDAHO FALLS WHERE AIRPORT REPORTING LOWER VISIBILITY. OTHER THAN
THE STRATUS...THE FORECAST PRETTY STRAIGHT FORWARD WITH COLD
NORTHERLY FLOW ALOFT PERSISTING THROUGH SATURDAY. VALLEY DOWN SLOPE
FLOW SHOULD INCREASE SATURDAY AND THINK THAT SHOULD ERODE THE
STRATUS FOR GOOD IN THE SNAKE PLAIN. FLOW ALOFT GETS CONVOLUTED
ON SUNDAY AS PACIFIC TROF COMES ON SHORE BUT SHOULD HAVE LITTLE
EFFECT ON SOUTHEAST IDAHO AS MOISTURE SHOULD NOT MAKE IT INTO
REGION. SO OVERALL EXPECT LITTLE TO NO PRECIPITATION THROUGH
SUNDAY. WILL BE VERY COLD DESPITE THE STRATUS ELEVATING
TEMPERATURES IN THE SNAKE PLAIN. HIGH TEMPERATURES ARE WELL BELOW
NORMAL FOR THE MOST PART.
GK
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY.
RIDGE OF HIGH PRESSURE BEGINS TO MOVE EAST AND THE NEXT STORM SYSTEM
WILL BE COMING ASHORE. LOOKS MORE LIKELY THAT THIS SYSTEM WILL SPLIT
WITH MOST OF THE ENERGY HEADED WELL SOUTH OF THE AREA. THE PATTERN
BECOMES NEARLY ZONAL AFTER THE SPLIT WITH LOTS OF WEAK SYSTEMS
MOVING THROUGH THE AREA. WILL CONTINUE TO MENTION SLIGHT CHANCES IN
THE MOUNTAINS...PERHAPS BETTER CHANCES EVERYWHERE MID TO LATE WEEK
AS A MORE POTENT SYSTEM COMES ASHORE.
&&
.AVIATION...LOW STRATUS AND FOG WILL CONTINUE TO BE PROBLEMATIC
ACROSS THE SNAKE PLAIN TODAY. MODELS DO NOT SHOW THIS MOISTURE
BREAKING UP UNTIL MAYBE SATURDAY. EXPECT IFR/MVFR CONDITIONS MOST
PLACES.
&&
.AIR STAGNATION...A BLOCKING RIDGE OF HIGH PRESSURE POSITIONED
ACROSS THE WRN STATES IS EXPECTED TO DOMINATE THE WEATHER PATTERN
THROUGH SUNDAY. BY MONDAY...PAC SYSTEMS ARE EXPECTED TO BEGIN TO
UNDER-CUT THE RIDGE AND BY AS EARLY AS TUESDAY THE SURFACE BASED
INVERSION MAY BREAK ACROSS SE IDAHO. HUSTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
