Weather Service Report


425 
FXUS65 KPIH 231950
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
150 PM MDT SAT AUG 23 2014

.SHORT TERM...TONIGHT THROUGH TUESDAY. THE LATEST SATELLITE IMAGERY 
WAS SHOWING A LOW PRESSURE SYSTEM OVERHEAD WITH SEVERAL WELL DEFINED 
VORT FEATURES EMBEDDED IN THE FLOW. CURRENT RADAR TRENDS ARE SHOWING 
A RAPID INCREASE IN SHOWER ACTIVITY EARLY THIS MORNING AND CURRENTLY 
ANTICIPATE THIS CONTINUE AND BECOME MORE LINEARLY FOCUSED THROUGH 
THE AFTERNOON AS ONE OF THE EMBEDDED VORT FEATURES PLUNGES SOUTH 
THROUGH THE SNAKE RIVER PLAIN AND THE SURFACE WINDS BEGIN TO FORM A 
CONVERGENCE AREA WITH THUNDERSTORMS ACROSS THE UPPER VALLEY THAT 
DRIFTS SOUTH LATE THIS AFTERNOON BEFORE DISSIPATING LATER THIS 
EVENING AS THE UPPER LOW BEGINS TO LIFT NE INTO SRN MONTANA. 
ANTICIPATING A BRIEF BRAKE IN THE ACTION SUNDAY MORNING BEFORE THE 
NEXT PAC THROUGH DIGS INTO THE NW STATES SUNDAY AFTERNOON FURTHER 
WEST THAN PREVIOUS PROGS SPINNING UP A SHALLOW CLOSED LOW OVER THE 
NRN GREAT BASIN SUNDAY AFTERNOON/NIGHT WITH AN INCREASE IN SHOWER 
ACTIVITY WHICH LINGERS THROUGH MONDAY NIGHT/TUESDAY AS THE LOW 
SLOWLY FILLS AND GRADUALLY SWINGS EAST ALONG THE NEVADA/UTAH BORDER 
BEFORE EXITING EAST OF THE REGION TUESDAY EVENING.

.LONG TERM...TUESDAY NIGHT THROUGH NEXT SATURDAY. DRIER AND WARMER 
CONDITIONS DEVELOP ACROSS SRN IDAHO WEDNESDAY THROUGH FRIDAY AS A 
TRANSIENT UPPER RIDGE MIGRATES EAST ACROSS THE AREA AHEAD OF THE 
NEXT APPROACHING PAC STORM SYSTEM. THE 12Z GFS CONTINUES TO TAP INTO 
THE REMNANTS OF HURRICANE MARIE AS IT LIFTS NE OUT OF THE 
SUB-TROPICAL ERN PACIFIC WATERS OFF THE MEXICAN COAST TO A POSITION 
WELL OFF THE CALIFORNIA COAST FRIDAY AHEAD OF THE INCOMING TROUGH. 
AS THE TROUGH MOVES INLAND SATURDAY...THE GFS BEGINS TO INTERACT 
WITH THE SUB-TROPICAL MOISTURE PRODUCING WIDESPREAD SHOWER ACTIVITY 
ACROSS IDAHO. THE 12Z ECMWF TAKES MARIE ON A MORE NWRLY TRAJECTORY 
PREVENTING THE INCOMING TROUGH FROM TAPPING INTO THE MOIST 
SUB-TROPICAL SYSTEM WITH DRIER CONSEQUENCES. WE WILL CONTINUE TO 
MONITOR THE MODEL TRENDS FOR ANY CHANGE IN EITHER MODEL. HUSTON
&&

.AVIATION...UPPER LOW IS SLOWLY DRIFTING ACROSS SOUTHEAST IDAHO THIS 
AFTERNOON. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN THE 
COLD CORE REGION WITH MOST OF THE STRATIFORM PRECIP WRAPPING AROUND 
THE LOW INTO THE SALMON/CHALLIS AREA. STARTING TO SEE CEILINGS AT 
KIDA LIFT FROM IFR TO MVFR...AND SHOULD SCATTER OUT IN THE EARLY 
AFTERNOON. HRRR SIGNALS INCREASING SHOWER ACTIVITY AROUND 
MID-AFTERNOON AND INTO THE EVENING AS LOW MOVES INTO THE YELLOWSTONE 
AREA. FORECAST SOUNDINGS FAVORING 6000 FT TO 10000 FT CEILINGS 
OVERNIGHT INTO TOMORROW.  HINSBERGER
&&

.FIRE WEATHER...A LITTLE LESS COVERAGE OF SHOWERS AND THUNDERSTORMS 
TODAY AS UPPER LOW SLOWLY DRIFTS ACROSS SOUTHEAST IDAHO TODAY. 
HEAVIER PRECIP IS BEING WRAPPED AROUND THE LOW INTO LEMHI COUNTY. 
DRIER WEATHER IS EXPECTED SUNDAY AS INFLUENCE OF LOW WANES...BUT 
MODELS ARE PROJECTING ANOTHER UPPER LOW TO DROP INTO OR/ID SUNDAY 
NIGHT. IMPULSES OF ENERGY AROUND THE LOW WILL BRING MORE SHOWERS AND 
THUNDERSTORMS TO THE AREA DURING THE DAY MONDAY...AND MAY LINGER 
INTO TUESDAY MORNING. UPPER RIDGING WILL BRING DRIER WEATHER TO THE 
REGION LATER ON TUESDAY AND SHOULD LAST THROUGH FRIDAY. A PACIFIC 
TROUGH WILL APPROACH THE WEST ON FRIDAY. REMNANTS OF HURRICANE MARIE 
MAY BE POSITIONED TO CONTRIBUTE ITS TROPICAL MOISTURE THOUGH THERE 
IS STILL SOME UNCERTAINTY WITH ITS TRACK IN RELATION TO THE PACIFIC 
TROUGH...BUT SIGNS POINT TO ANOTHER WET WEEKEND.  HINSBERGER 
&&

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

$$







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