FXUS65 KPIH 151003
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
303 AM MST TUE DEC 15 2009

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT. STRONG SOUTHWESTERN
PUSH OF MOISTURE MOVING ONSHORE IN THE NORTHWEST COAST THIS
MORNING. RIDGING IN PLACE OVER EASTERN IDAHO HAS PUT AN END TO THE
SNOW SHOWERS WITH A FEW EXCEPTIONS NEAR THE MONTANA BORDER. THIS
RIDGING WILL FLATTEN AND TURN MORE ZONAL THROUGH THE DAY WHILE THE
STREAM OF MOISTURE SAGS INTO THE FORECAST AREA. SNOW WILL PUSH IN
THE EASTERN BORDER OF THE AREA THIS MORNING THEN SPREAD EAST BY
THIS AFTERNOON. THIS STREAM OF MOISTURE WILL PERSIST WELL INTO
WEDNESDAY...HOWEVER EXPECT IT TO BE STEADY BUT RELATIVELY LIGHT.
HIGHER ELEVATIONS WILL PROVIDE THE GREATEST LIFT AND INSTABILITY
AND WILL THEREFORE SEE THE GREATEST SNOWFALL AMOUNTS. A WINTER
STORMS WARNING REMAINS IN EFFECT IN THE SAWTOOTH AND WOOD RIVER
AREAS AND THE WATCH WILL BE UPGRADED TO A WARNING FOR THE ISLAND
PARK AREA. LESSER AMOUNTS ARE EXPECTED IN THE SOUTHERN HIGHLANDS
WHERE A WINTER WEATHER ADVISORY IS IN EFFECT...WHILE THE SNAKE
PLAIN WILL SEE ONLY A FEW INCHES AND MAY MIX WITH RAIN AT TIMES
TODAY AND WEDNESDAY. THE BULK OF PRECIPITATION WILL TAPER OFF
WEDNESDAY NIGHT WITH BRIEF WEAK RIDGING NOSING INTO IDAHO. EXPECT
ONLY ISOLATED TO SCATTERED SNOW SHOWERS INTO THURSDAY
NIGHT...PRIMARILY IN THE HIGHER ELEVATIONS.

.LONG TERM...FRIDAY THROUGH NEXT TUESDAY. BOTH GFS/ECMWF MODEL
RUNS SHOWING A BIT MORE AMPLITUDE TO RIDGE OVER REGION FRIDAY AND
SATURDAY THAN PREVIOUS SOLUTIONS. MODELS BEGIN TO DIVERGE BEYOND
THAT TIME FRAME AS ECMWF STAYS WITH RIDGE SCENARIO THROUGH TUESDAY
BEFORE BRINGING NEXT PAC LOW INLAND. THE GFS ON THE OTHERHAND IS
MORE PROGRESSIVE WITH ENERGY WORKING INLAND AS EARLY AS SUNDAY.
THUS HAVE TRIMMED PRECIPITATION POTENTIAL BACK MOST AREAS THROUGH
SUNDAY THEN TRENDED TOWARD CLIMATOLOGICAL MENTION OF PRECIPITATION
BY MONDAY/TUESDAY. RUN TO RUN MODEL CONSISTENCY HAS BEEN POOR SO
CONFIDENCE IN ANY ONE SOLUTION IS LOW AT THIS TIME. GENERALLY
FOLLOWING STATISTICAL TEMPERATURE GUIDANCE THROUGHOUT FORECAST
PERIOD. HUSTON

&&

.AVIATION...MOIST PACIFIC SYSTEM PUSHING INLAND EARLY THIS
MORNING WITH ASSOCIATED PRECIPITATION AND IFR CIGS AND VISIBILITY
EXPECTED TO BEGIN IMPACTING CNTRL MOUNTAINS (KSUN) AS EARLY AS
11AM MDT TODAY THEN SPREADING INTO SNAKE PLAINS
(KBYI...KPIH...KIDA) BY APPROXIMATELY 5PM MDT. IFR CONDITIONS WILL
LIKELY CONTINUE THROUGH WEDNESDAY MORNING. HUSTON

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 11 AM THIS MORNING TO 5 PM MST 
WEDNESDAY FOR IDZ019.

WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 11 AM 
MST WEDNESDAY FOR IDZ017-022.

WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 11 AM MST 
WEDNESDAY FOR IDZ018-031.

&&

$$