Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 190918
AFDPIH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO ID
318 AM MDT SAT JUL 19 2014

.SHORT TERM...TODAY THROUGH SUNDAY AFTERNOON. WESTERLY FLOW REMAIN
IN PLACE TODAY JUST BRINGING WITH SOME CLOUDS BUT MORE DRY
WEATHER. IT WILL BE BREEZY ESPECIALLY IN THE AFTERNOON AND EVENING
HOURS. WE SHOULD HIT THE LOW END THRESHOLD FOR A LAKE WIND
ADVISORY FOR AMERICAN FALLS RESERVOIR...BUT JUST ABOUT ALL BODIES
OF WATER WILL LIKELY SEE SOME ROUGH CONDITIONS. WE TRANSITION TO
SOUTHWEST FLOW TOMORROW AS ANOTHER STORM DEVELOPS ALONG THE WEST
COAST. THIS WILL FINALLY PULL THE MONSOON MOISTURE TO OUR SOUTH
INTO EASTERN IDAHO. WE MAY SEE A STRAY SHOWER OR STORM SUNDAY
MORNING BUT DEVELOPMENT WILL RAMP UP IN THE AFTERNOON. THE BEST
CHANCE OF SEEING STORMS WILL BE SOUTH OF A STANLEY-ARCO-
BLACKFOOT-DRIGGS LINE. THE HIGHEST CHANCES WILL BE SOUTH OF THE
SNAKE PLAIN. BRIEF DOWNPOURS WILL BE POSSIBLE WHERE STORMS CAN TAP
INTO A LITTLE BETTER MOISTURE BUT THE BIGGER THREAT WILL BE FROM
DOWNBURST WINDS THAT MAY BE IN EXCESS OF 50MPH. TEMPERATURES WILL
REMAIN ABOVE AVERAGE BY SEVERAL DEGREES BOTH DAYS EVEN WITH
INCREASING CLOUDS SUNDAY. KEYES

.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE BIG PUSH OF
MONSOON MOISTURE WILL BE SUNDAY NIGHT AND MONDAY. THERE WILL BE
PLENTY OF MOISTURE TO TAP INTO FOR RAIN...INCLUDING LOCALLY HEAVY
RAIN WITH STRONGER STORMS. RIGHT NOW...THERE IS SOME UNCERTAINTY
ON HOW UNSTABLE THINGS WILL BE BY MONDAY. THIS WILL PLAY INTO WHEN
AND WHERE WE COULD GET STRONG STORMS AND POSSIBLY SEVERE STORMS TO
FIRE OFF. THE MODELS SEEMS TO HINT AT THE LEADING BAND TO SLOWLY
PUSH INTO THE CENTRAL MOUNTAINS AND UPPER SNAKE HIGHLANDS BY
MONDAY AND REMAIN THERE. IF SO...THAT AREA WOULD BE MORE CLOUDY
AND STABLE...LEADING TO MORE GENERAL RAIN AND LESS STORMS. TO THE
SOUTH...THAT MAY BE WHERE THE MORE POWERFUL STORMS COULD FIRE DUE
TO LESS CLOUD COVER AND BETTER INSTABILITY. FOR NOW WE ARE GOING
WITH SHOWERS AND ISOLATED STORMS ACROSS THE BOARD UNTIL WE GET A
BETTER HANDLE ON THIS. MONDAY DEFINITELY LOOKS COOLER WITH MORE
CLOUDS AROUND. TUESDAY AND WEDNESDAY LOOK DRIER AS THE LOW
CONTINUES TO STAY TO OUR NORTHWEST. THE MODELS ARE KEYING IN ON
ANY REAL CHANCE OF SHOWERS AND STORMS BEING ACROSS THE CENTRAL
MOUNTAINS AND UPPER SNAKE HIGHLANDS. THE LOW FINALLY SHIFTS INTO
SOUTHERN CANADA FOR THE END OF THE WEEK AND TURNING THE FLOW BACK
TO WESTERLY AND A RIDGE BUILDING BACK TOWARD IDAHO. THIS WILL
SIGNAL A QUICK RETURN TO VERY DRY WEATHER. WITH THE DRY AIR IN
PLACE...THIS WILL ALLOW FOR COOLER NIGHTS BUT ALSO WARM
AFTERNOONS SIMILAR TO WHAT WE`VE SEEN THE PAST FEW DAYS. KEYES

&&

.AVIATION...UPPER LOW SHEARING EAST THROUGH CANADA WILL SUSTAIN A
DRY AND STABLE NW FLOW ALOFT ACROSS SE IDAHO TODAY. EXPECT VFR SCT
HIGH CLOUDS AND GUSTY AFTERNOON WINDS AT ALL TERMINALS TODAY. HUSTON

&&

.FIRE WEATHER...THE PACIFIC STORM TRACK WAS POSITIONED ALONG THE
CANADIAN BORDER EARLY THIS MORNING WHILE A PAIR OF PAC LOWS WERE
NOTED SHEARING EAST THROUGH WRN CANADA. THESE PASSING FEATURES WILL
HELP TO GENERATE ANOTHER ROUND OF GUSTY WINDS AND LOW RH ACROSS THE
REGION TODAY...THUS A RED FLAG WARNING HAS BEEN ISSUED FOR FIRE
ZONES 410 422 425 AND 427 FOR THIS AFTERNOON AND EVENING. THE STORM
TRACK REMAINS JUST NORTH OF THE REGION SUNDAY WHILE SUB-TROPICAL
MOISTURE THAT HAS BEEN POOLING ACROSS THE GREAT BASIN BEGINS TO
SURGE NORTH THROUGH NEVADA AND INTO THE BORDER DISTRICTS SUNDAY
AFTERNOON. BELIEVE THAT THE BEST DYNAMICAL SUPPORT FOR WIDESPREAD
TSTM ACTIVITY RESIDES OVER NWRN NEVADA AND THAT SRN IDAHO WILL ONLY
SEE ISOLATED COVERAGE SUNDAY AFTERNOON. ZONES 410 AND 422 MAY NEED
FURTHER EXAMINATION FOR A POTENTIAL RED FLAG WIND/LOW RH EVENT
SUNDAY AFTERNOON. CONFIDENCE IS MIXED AT THIS POINT DUE TO INFLUX OF
MOISTURE/CLOUDS FROM THE SOUTH WHICH MAY INHIBIT FULL
HEATING/MIXING. BY MONDAY...A FAIRLY DEEP PAC LOW SWINGS INTO THE
CANADIAN COASTAL WATERS AMPLIFYING THE MOIST SUB-TROPICAL FETCH
ACROSS SRN IDAHO. MAIN QUESTION HERE IS WILL IT BE TOO
CLOUDY...DIMINISHING THUNDERSTORM POTENTIAL DUE TO THE LACK OF
HEATING...OR WILL EJECTING DISTURBANCES LIFTING NE THROUGH
OREGON/NRN IDAHO BE ENOUGH TO FORCE SCATTERED THUNDERSTORM ACTIVITY
(AND A RED FLAG EVENT). MORE QUESTIONS THAN ANSWERS AT THIS POINT
SO WILL CONTINUE TO DIGEST MODEL OUTPUT TO SEE WHICH WAY TO LEAN.
WEDNESDAY OR THURSDAY OF NEXT WEEK...THE LOW OFF THE NW COAST KICKS
INLAND AND WE SHOULD SEE A FAIRLY DECENT FRONTAL PASSAGE AND BREEZY
CONDITIONS ACROSS THE AREA AS A RESULT. THE LATEST MODEL RUNS APPEAR
TO BE DELAYING THE RESURGENCE OF THE 4-CORNERS HIGH AND HOTTER
TEMPERATURES UNTIL LATE IN THE WEEKEND OR EARLY NEXT WEEK. HUSTON

&&

.AIR STAGNATION...SMOKE FROM NUMEROUS FIRES ACROSS THE WEST WILL
REMAIN IN PLACE ACROSS EASTERN IDAHO. WITH THE WIND FLOW COMING
FROM THE WEST...THIS WILL HELP TO KEEP SMOKE AROUND EVEN WITH
BREEZY CONDITIONS IN THE AFTERNOON AND EVENING HOURS. SOME RELIEF
MAY COME LATER SUNDAY INTO MONDAY FOR TWO REASONS. SHOWERS AND
THUNDERSTORMS WILL OVER TAKE THE AREA...WITH RAIN POTENTIALLY
CLEARING OUT THE AIR. THE SECOND WILL BE A SWITCH TO MORE
SOUTHERLY/SOUTHWESTERLY FLOW WHICH WOULD HELP DIRECT MORE OF THE
SMOKE INTO MONTANA AND NORTHERN IDAHO. DUE TO POOR AIR
QUALITY...AN AIR QUALITY ALERT IS IN EFFECT FOR
BLAINE...CASSIA...LINCOLN AND MINIDOKA COUNTIES THROUGH MONDAY
UNLESS IT IS CANCELLED EARLY.  KEYES

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 9 PM MDT THIS
EVENING IDZ410-422.-425-427.

LAKE WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 9 PM MDT THIS
EVENING IDZ021.

&&

$$







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