993  
FXUS65 KPIH 100842  
AFDPIH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE POCATELLO ID  
242 AM MDT WED AUG 10 2022  
   
SHORT TERM
 
TODAY THROUGH THURSDAY NIGHT.  
A DYNAMIC WEATHER DAY IS IN STORE ACROSS EASTERN IDAHO TODAY WITH A  
CLOSED UPPER LEVEL LOW OFF THE PACIFIC COAST AND BROAD HIGH PRESSURE  
CENTERED OVER THE CENTRAL UNITED STATES DRIVING STRONG MONSOONAL  
MOISTURE UP THROUGH THE GREAT BASIN. BEING IN A FAVORED MOISTURE  
TRANSPORT REGION TODAY IN BETWEEN THESE TWO UPPER LEVEL FEATURES,  
MOIST SOUTHWEST FLOW WILL BRING SCATTERED SHOWERS AND  
THUNDERSTORMS ALONG WITH THE POTENTIAL FOR FLASH FLOODING CONCERNS  
AND POTENTIALLY SEVERE GUSTY OUTFLOW BOUNDARIES. THE WEATHER  
PREDICTION CENTER HAS ISSUED A SLIGHT 15 PERCENT RISK FOR  
EXCESSIVE RAINFALL EXCEEDING FLASH FLOOD GUIDELINES EXTENDING FROM  
THE NEVADA/UTAH BORDER REGION IN SOUTH-CENTRAL IDAHO UP THROUGH  
THE FRANK CHURCH WITH A MARGINAL 5 PERCENT RISK FOR THE REMAINDER  
OF SOUTHEAST IDAHO. PWATS BETWEEN 0.75 AND 1.50 INCHES WILL  
APPROACH 3 TO 5 SIGMA ABOVE NORMAL NEARING 200 TO 300 PERCENT OF  
NORMAL FOR THIE TIME OF YEAR ACROSS THE REGION THIS AFTERNOON AND  
EVENING. PRECIPITATION WILL START OFF TODAY IN WESTERN IDAHO,  
GRADUALLY WORKING EAST THROUGHOUT THE DAY WITH AFTERNOON  
CONVECTION HELPING TO INITIATE AND DEVELOP STRONG THUNDERSTORMS.  
THE MAIN CONCERN WITH THUNDERSTORMS TODAY WILL BE LOCALIZED FLASH  
FLOODING CONCERNS, STRONG GUSTY OUTFLOW WINDS, AND HAIL UP TO  
AROUND HALF-INCH TO QUARTER SIZE WITH SUFFICIENTLY AVAILABLE  
DCAPE/CAPE IN ADDITION TO 30 TO 50 KTS OF 0 TO 6 KM SHEAR  
ENABLING THE ENVIRONMENT TODAY TO PRODUCE STRONG THUNDERSTORMS.  
 
THE DEVELOPMENT OF MODERATE TO HEAVY PRECIPITATION ASSOCIATED WITH  
AREAS OF CONVECTION WILL BEGIN MID-AFTERNOON BETWEEN 2 TO 4PM AND  
EXTEND THROUGH ABOUT MIDNIGHT WITH LINGERING SHOWERS OVERNIGHT  
ACROSS THE HIGHER TERRAIN NORTH AND EAST AND ACROSS THE EASTERN  
SNAKE PLAIN. AFTER A BRIEF BREAK TOMORROW MORNING FROM  
PRECIPITATION, THERE WILL BE THE POTENTIAL FOR PATCHY FOG  
DEVELOPMENT ACROSS THE SNAKE PLAIN GIVEN SATURATED LOWER LAYERS AND  
QUIETER WINDS BUT WITH CLOUD COVER OVERHEAD, THIS COULD STIFLE ANY  
SIGNIFICANT FOG DEVELOPMENT. IN AREAS THAT DO GET TO SEE THOSE CLEAR  
SKIES, CHANCES WILL INCREASE GIVEN MORE EFFECTIVE RADIATIVE COOLING.  
KEEP AN EYE ON THE SKY THROUGHOUT THURSDAY MORNING AND YOU WILL SEE  
TOWERING CUMULUS BUILDING OVER THE HIGHER TERRAIN FOR ANOTHER DAY OF  
AFTERNOON SHOWERS AND THUNDERSTORMS BUT WITH SCATTERED COVERAGE  
REMAINING OVER THE HIGHER TERRAIN AS MORE ISOLATED COVERAGE MOVES IN  
FOR THE SNAKE PLAIN AND MAGIC VALLEY. THE WPC HAS AGAIN ISSUED A  
MARGINAL 5 PERCENT RISK FOR EXCESSIVE RAINFALL EXCEEDING FLASH  
FLOOD GUIDANCE FOR THURSDAY ACROSS ALL OF SOUTHEAST IDAHO WITH A  
PREDOMINANT FOCUS ON THE HIGHER TERRAIN. TEMPERATURES THROUGH THE  
PERIOD WILL REMAIN NEAR NORMAL IF NOT ABOVE NORMAL TODAY IN THE  
80S TO MID 90S, COOLING SLIGHTLY FOR THURSDAY INTO THE 80S TO LOW  
90S. SYNOPTIC WINDS OUTSIDE OF CONVECTION BE UP TO AROUND 20 TO 30  
MPH WITH THUNDERSTORMS CAPABLE OF PRODUCING WINDS IN EXCESS OF 40  
TO 50 MPH. MACKAY  
   
LONG TERM
 
FRIDAY THROUGH NEXT WEDNESDAY.  
THE MODELS AND CLUSTER FORECASTS ARE FAIRLY CONSISTENT ON MONSOON  
MOISTURE REMAINING ACROSS CENTRAL AND EASTERN IDAHO INTO NEXT  
WEEK. THERE WILL BE SOME DAILY FLUCTUATIONS IN WHERE THE BEST  
CHANCE AND ALSO WHERE HEAVIER RAINFALL WILL OCCUR, BUT THE GENERAL  
IDEA IS OVER THE HIGHER ELEVATIONS...ESPECIALLY THE SOUTHERN AND  
EASTERN HIGHLANDS. THIS PATTERN IS ALSO CONDUCIVE TO POTENTIALLY  
SEE AN UPTICK ACROSS THE CENTRAL MOUNTAINS FROM THE WOOD RIVER  
VALLEY TO AROUND GILMORE SUMMIT. WE WILL HAVE TO MONITOR HOW MUCH  
RAIN FALLS IN THE COMING DAYS TO SEE WHERE ANY RISK FROM FLASH  
FLOODING/DEBRIS FLOWS EVOLVES AS WHERE GET INTO THE WEEKEND AND  
NEXT WEEK. AFTERNOON TEMPERATURES WILL GENERALLY BE AT OR JUST  
BELOW AVERAGE BASED ON THE BLEND OF MODELS. HOWEVER, A LOT OF THAT  
WILL BE FLUCTUATING DAY TO DAY BASED ON WHERE WE SEE MORE SUN VS  
CLOUDS DOWN THE ROAD.  
 

 
   
AVIATION
 
 
THE START OF MORE MONSOONAL MOISTURE MAKES IT INTO THE AREA TODAY.  
RAIN CHANCES INCREASE AT KSUN IN THE FIRST HALF OF THE DAY BEFORE  
MOISTURE SPREADS FARTHER EAST WITH MORE WIDESPREAD RAIN AND STORMS  
HEADING TOWARDS KBYI, KPIH, KIDA, AND KDIJ AROUND 23Z WEDNESDAY.  
CONDITIONS COULD DROP TO MVFR OR EVEN IFR AS RAIN PASSES OVER THE  
TERMINALS DUE TO REDUCED VISIBILITY. MOST OF THE ACTIVITY WRAPS UP  
AROUND 09Z THURSDAY. WITH LIGHT WINDS EARLY THURSDAY, THERE IS THE  
POTENTIAL FOR SOME DEVELOPMENT OF LIGHT MIST, THOUGH CONFIDENCE IS  
NOT HIGH DUE TO SOME DISAGREEMENT BETWEEN CAMS.  
 

 
   
FIRE WEATHER
 
 
TODAY BEGINS SEVERAL DAYS OF SHOWERS AND THUNDERSTORMS ACROSS  
CENTRAL AND EASTERN IDAHO, AS MONSOON MOISTURE CONTINUES TO STREAM  
INTO OUR AREA. THE FOCUS FOR HEAVIER RAINFALL WILL BE ACROSS THE  
WESTERN HALF OF OUR FIRE FORECASTING AREA, MEANING ZONES 475, 476,  
422, 425, 427, AND 410/411 WEST OF I-15. THERE IS A 40-60% CHANCE  
OF WETTING RAINS, ESPECIALLY WHERE WE CAN MULTIPLE STORMS TO  
TRACK OVER THE SAME LOCATIONS, ACROSS THOSE ZONES. IN FACT, THERE  
IS A 20-30% CHANCE OF SEEING BETWEEN 0.25-0.5" IN SOME OF THOSE  
SAME LOCATIONS. THE PROBABILITY OF MORE THAN 0.50" RAPIDLY DROPS  
OFF TO 10% OR LESS. THIS FITS THE CURRENT TREND WHERE BETTER AND  
DEEPER MOISTURE ARRIVES WITH THE MONSOON PUSH LATER TODAY. THAT  
SAID, IT DOES LOOK LIKE ONCE YOU GET TOWARD THE NORTHERN END OF  
475 AND THE MOOSE FIRE, WETTING RAINS LOOK LESS LIKELY...MAYBE  
ONLY AS HIGH AS 30%. IN FACT, ONCE YOU GET FARTHER EAST...THE  
PROBABILITY BARELY PUSHES ABOVE 30% AS THE PUSH OF DEEPEST  
MOISTURE DOESN'T SHIFT FAR ENOUGH EAST UNTIL TONIGHT AND FRIDAY.  
SOME OF THESE STORMS TODAY MAY PRODUCE WINDS OVER 40 MPH AND SMALL  
HAIL. THE GREATEST RISK OF HIGHER WINDS WILL BE WITH STORMS THAT  
ARE INITIALLY "DRIER" ACROSS PORTIONS OF THE SNAKE PLAIN (410),  
MAGIC VALLEY(425), AND SOUTH HILLS(427). WITH THE SHIFT IN BETTER  
MOISTURE EAST THURSDAY, SCATTERED COVERAGE LOOKS TO BE MAINLY  
ACROSS 476 IN THE CENTRAL MOUNTAINS, THE SNAKE PLAIN AND  
SOUTHERN/EASTERN HIGHLANDS(410/411/413). WETTING RAIN POTENTIAL IS  
HIGHEST ACROSS ZONE 413 AT 30-50%. ELSEWHERE, THE CHANCE IS 30%  
OR LOWER. AMOUNTS OVER 0.25 WILL BE SPOTTY, BUT STILL POSSIBLE  
ACROSS PORTIONS OF ZONES 476, 411 AND 413 WHERE THE PROBABILITY  
EXCEEDS 20%. THE RISK OF STRONG WINDS DROPS OFF TOMORROW, BUT SOME  
STORMS MAY STILL EEK OUT WINDS OVER 30 MPH. BEYOND THAT, THE  
PATTERN REMAINS IN PLACE. WE WILL NEED TO MONITOR TRENDS,  
ESPECIALLY WHEN WE CAN GET HIGHER RESOLUTION DATA IN THE MIX, TO  
SEE WHERE WE CAN TARGET HIGHER CHANCES AND HIGHER RAINFALL.  
 

 
   
PIH WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
WWW.WEATHER.GOV/POCATELLO  
WWW.FACEBOOK.COM/NWSPOCATELLO  
WWW.TWITTER.COM/NWSPOCATELLO  
 
SHORT TERM...MACKAY  
LONG TERM...KEYES  
AVIATION...AMM/KEYES  
FIRE WEATHER...KEYES  
 
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