Area Forecast Discussion
Issued by NWS Pocatello, ID

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
000
FXUS65 KPIH 301447
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
847 AM MDT SAT MAY 30 2015

.UPDATE...SHOWERS HAVE DEVELOPED ACROSS THE CENTRAL MOUNTAINS AND
WEST THROUGH NORTHEAST OREGON THIS MORNING. MODELS MAINTAIN ENOUGH
MOISTURE AND INSTABILITY MAINLY HIGHER ELEVATIONS TODAY FOR
ADDITIONAL CONVECTIVE DEVELOPMENT THROUGH THE AFTERNOON AND
EVENING. 12Z NAM HAS BACKED OFF SLIGHTLY ON AMOUNT OF PRECIP
EXTENDING INTO THE SNAKE PLAIN TODAY. HOWEVER SFC DEWPOINTS IN
THE UPPER 40S AND JUST ENOUGH INSTABILITY TO MAINTAIN ISOLATED
MENTION THIS AFTERNOON. HAVE NUDGED POPS HIGHER MAINLY THIS
MORNING THROUGH THE CENTRAL MTNS FOR AFOREMENTIONED ONGOING WEAK
ACTIVITY AND TWEAKED COVERAGE FOR THIS AFTERNOON WITH RECENT MODEL
TRENDS. DMH


&&

.PREV DISCUSSION... /ISSUED 315 AM MDT SAT MAY 30 2015/

SHORT TERM...SATURDAY THROUGH MONDAY.
A WEAK UPPER LEVEL SYSTEM WILL MOVE OVER THE UPPER LEVEL RIDGE IN
IDAHO AND BRING SHOWERS AND THUNDERSTORMS TODAY MAINLY TO THE
CENTRAL MOUNTAINS AND SOUTHERN AND EASTERN HIGHLANDS. EXPECT
ISOLATED ACTIVITY IN THE SNAKE RIVER PLAIN. TEMPERATURES WILL
CONTINUE TO MODERATE WITH LOW 80S EXPECTED IN SNAKE PLAIN AND 70S
IN THE MOUNTAINS. SUNDAY SHOULD SEE CONTINUED WARMING WITH
SOUTHERLY FLOW ALOFT INCREASING. HIGHS WILL BE IN THE 70S IN THE
MOUNTAINS TO MID TO UPPER 80S IN THE SNAKE RIVER PLAIN. EXPECT
SHOWERS AND THUNDERSTORMS TO BE CONFINED MAINLY TO THE MOUNTAINS
ON SUNDAY. FIRST UPPER LEVEL TROF BEGINS TO MOVE TO THE NORTH OF
IDAHO ON MONDAY AND THE SOUTHERLY FLOW WILL KEEP THE THREAT OF
SHOWERS AND THUNDERSTORMS GOING MONDAY. TEMPERATURES WILL BEGIN TO
COOL DOWN AS WELL.
GK

LONG TERM...TUESDAY THROUGH SATURDAY.
A SECOND TROF APPROACHES IDAHO LATE NEXT WEEK THURSDAY THROUGH
SATURDAY. EUROPEAN M MODEL CLOSES OFF A LOW IN NEVADA BY SATURDAY
WHILE GFS IS MORE OPEN AND PROGRESSIVE WITH THE TROF. GFS IS THE
MUCH DRIER SOLUTION WITH MOST ENERGY TO NORTH WHILE THE EUROPEAN
IS MUCH WETTER. FOR NOW JUST KEPT IN THE SHOWERS AND THUNDERSTORMS
ALREADY IN GRIDS NEXT WEEK AS MODEL UNCERTAINTY AND DIFFERENCES
ARE LEADING ME TO NOT MAKE TOO MANY CHANGES. TEMPERATURES SHOULD
BE NEAR SEASONAL NORMAL THROUGH THE PERIOD.
GK

AVIATION...A FLAT RIDGE WAS POSITIONED OVER THE REGION EARLY THIS
MORNING AS A PAC DISTURBANCE WAS SHEARING EAST INTO/THROUGH THE
PANHANDLE. THE MODELS SUPPORT SCATTERED SHOWERS NEAR KSMN THIS
MORNING WITH THUNDERSTORMS BREAKING OUT NORTH OF A LINE FROM KETCHUM
TO SPENCER THIS AFTERNOON. FURTHER SOUTH...STRONG SURFACE HEATING
WILL PROMOTE CONVECTION HOWEVER THERE SEEMS TO BE SOME DISAGREEMENT
BETWEEN THE NAM AND GFS OVER THE EXTENT OF AVAILABLE LOW LEVEL
MOISTURE TO FUEL THUNDERSTORM DEVELOPMENT. HARD TO SAY AT THIS POINT
WHICH MODEL HAS THE BETTER HANDLE ON DEPTH OF BOUNDARY LAYER
MOISTURE SO WE WILL ADD A MENTION OF VCTS TO KBYI...KPIH AND KIDA TO
COVER THE POTENTIAL FOR BUILDUPS FROM 21-03Z TODAY. HUSTON

FIRE WEATHER...A BROAD/FLAT RIDGE OF HIGH PRESSURE WAS POSITIONED
OVER THE WRN STATES EARLY THIS MORNING AS THE NEXT UPSTREAM PAC LOW
WAS ADVANCING TOWARD THE CALIFORNIA COAST. A DISTURBANCE EJECTING
FROM THE PAC LOW WILL TOP THE RIDGE OVER NRN IDAHO TODAY RESULTING
IN SCATTERED SHOWERS AND AFTERNOON THUNDERSTORMS FOCUSED PRIMARILY
ACROSS THE CNTRL MOUNTAINS NORTH OF HAILEY AND EAST TO THE MONTANA
BORDER. THERE MAY BE ENOUGH MOISTURE AND INSTABILITY ACROSS THE
SOUTHERN HIGHLANDS TO SUPPORT ISOLATED BUILDUPS IN THAT REGION LATE
THIS AFTERNOON/EVE. THE RIDGE AMPLIFIES OVER THE GREAT BASIN SUNDAY
AS THE PAC LOW REACHES THE NRN CALIFORNIA COAST RESULTING IN
SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS FOCUSED OVER SW
MONTANA AND TO A LESSER EXTENT THE BORDER REGIONS OF THE CNTRL AND
NE MOUNTAINS. THE LOW LIFTS INTO WASHINGTON AND OREGON SUNDAY
NIGHT/MONDAY RESULTING IN SOME FAIRLY DECENT DYNAMICAL FORCING
ACROSS SW IDAHO INTO THE CNTRL MOUNTAINS...IDAHO PANHANDLE AND WRN
MONTANA MONDAY AFTERNOON...POSSIBLY IMPACTING THE SAWTOOTH AND
SALMON-CHALLIS REGION WITH ENHANCED OR POTENTIALLY SEVERE
THUNDERSTORM ACTIVITY. A BROAD TROUGH LINGERS OVER THE REGION
TUESDAY THROUGH FRIDAY SUPPORTING A CHANCE MENTION OF SHOWERS AND
AFTERNOON THUNDERSTORMS CONTINUING INTO THE LATTER HALF OF THE WEEK.
HUSTON


&&

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

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.