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000
FXUS65 KPIH 190900
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
300 AM MDT SUN MAY 19 2013

.DISCUSSION...ACTIVE TROUGH CONTINUES OVER THE NORTHERN ROCKIES
AND PACNW. WV SAT IMAGERY SHOWS A WEAK CIRCULATION OVER EASTERN
IDAHO WITH WEAK CONVECTION OCCURRING THIS MORNING IN THE UPPER
SNAKE PLAIN AND EASTERN HIGHLANDS. A SECOND STRONGER SHORTWAVE
SLIDING INTO WESTERN IDAHO THIS MORNING PROGGED TO REACH THE
REGION LATER TODAY. AIR MASS AGAIN WEAKLY UNSTABLE SO CONTINUED
HIGH CHANCE SHOWERS MOST LOCATIONS WITH ISOLATED THUNDERSTORMS
THIS AFTERNOON. SHORTWAVE EXITS THE REGION TONIGHT WITH FLOW ALOFT
TURNING NORTHERLY AHEAD OF BUILDING RIDGE. BOTH GFS AND NAM LINGER
SOME WEAK CONVECTION ALONG THE EASTERN HIGHLANDS INTO MONDAY BUT
OVERALL TREND IS DRIER. RIDGE AXIS IN PLACE FOR TUESDAY BUT GFS
HOLDING ON TO POTENTIAL FOR WEAK CONVECTION ALONG NORTHERN
FORECAST AREA BORDER. THUS KEPT WEAK COLLABORATION POPS ALONG THE
FRINGES OF THE REGION.

MUCH DEEPER UPPER LOW SETTLES INTO THE PACNW FOR MUCH OF THE
REMAINDER OF THE FORECAST PERIOD. MODELS IN GENERAL AGREEMENT WITH
CENTER OF THE LOW CIRCULATING OVER OREGON/WASHINGTON WITH MULTIPLE
SHORTWAVES ROTATING AROUND THE LOW ACROSS EASTERN IDAHO. THAT
SAID...BOTH GFS AND ECMWF REMAIN SOMEWHAT SKIMPY WITH QPF FIELDS
OVER EASTERN IDAHO AS LOW REMAINS WEST OF THE REGION THROUGH THURSDAY.
ECMWF SLIGHTLY WETTER THAN THE GFS...AND ENOUGH TO KEEP POPS
AROUND OR SLIGHTLY HIGHER THAN CLIMO THROUGH THAT TIME. BY
FRIDAY...BOTH MODELS BEGIN TO OPEN THE LOW AND LIFT IT NORTHEAST
ENDING IN SOUTHERN ALBERTA BY SATURDAY MORNING. GFS DROPS A
SECONDARY TROUGH ALONG THE COAST WITH DRY CONDITIONS OVER IDAHO
SATURDAY INTO SUNDAY WHILE THE ECMWF MAINTAINS A FLATTER AND
SLIGHTLY WETTER FLOW. MADE LITTLE CHANGE FROM PERSISTENCE FOR DAYS
7 TO 8. DMH

&&

.AVIATION...NORTHERLY FLOW ALOFT ON THE BACK SIDE AND EXISTING STORM
SYSTEM WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ACROSS
THE REGION TODAY.  MVFR CEILINGS ARE POSSIBLE THIS MORNING AT KIDA
AND KPIH.  THIS AFTERNOON ISOLATED THUNDERSTORMS MAY PRODUCE GUSTY
WINDS AND MVFR CEILINGS.  WINDS MAY GUST A LITTLE THIS AFTERNOON AS
WELL AS NEAR ANY THUNDERSTORMS.  PRESTON


&&

.FIRE WEATHER...ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE TODAY
ACROSS ALL DISTRICTS.  MONDAY AND TUESDAY A RIDGE OF HIGH PRESSURE
BUILDS WITH LIGHTER WINDS, WARMING TEMPERATURES AND LOWER RELATIVE
HUMIDITIES.  A LOW PRESSURE SYSTEM DEVELOPS IN THE PACIFIC NORTHWEST
BUT OUR AREA WILL REMAIN IN THE WARM AND DRY SECTOR EXPECT THE
CENTRAL IDAHO MOUNTAINS MAY SEE ISOLATED AFTERNOON THUNDERSTORM
POTENTIAL THROUGH FRIDAY.   PRESTON


&&

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

$$