AFDPDT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 1043 PM PDT THU JUN 2 2022 .UPDATED AVIATION DISCUSSION. UPDATE...LINGERING SHOWERS WILL AFFECT PORTIONS OF THE BLUE MOUNTAINS THE REST OF TONIGHT, MAINLY PRIOR TO MIDNIGHT. HOWEVER, AMOUNTS ARE EXPECTED TO BE LIGHT AND WILL REMAIN UNDER A QUARTER OF AN INCH. CURRENT THINKING IS MORE LIKELY A TENTH OF AN INCH OR LESS WILL BE SEEN BY MOST. CONFIDENCE IS HIGH (80%) OWING TO THE COMBINATION OF RADAR TRENDS AND THE LATEST GUIDANCE INVOLVING THE 00Z HREF AND THE LAST FOUR RUNS OF THE HRRR. THUS THE FLASH FLOODING THREAT HAS ENDED AND THE FLASH FLOOD WATCH WAS ALLOWED TO EXPIRE AT 9 PM PDT THIS EVENING. AS SUCH, ATTENTION TURNS TO FRIDAY AS THE PATTERN REMAINS UNSETTLED WITH ADDITIONAL CHANCES FOR SHOWERS. MODERATE RAINFALL AMOUNTS IN EXCESS OF A HALF INCH IS EXPECTED IN PARTS OF THE EASTERN MOUNTAINS ON FRIDAY. PREV DISCUSSION... /ISSUED 849 PM PDT THU JUN 2 2022/ EVENING UPDATE... SHOWERS AND T-STORMS ARE ON THE DECREASE THIS EVENING AS THE BULK OF THE ACTIVITY HAS SHIFTED NORTH OF OUR CWA INTO PORTIONS OF EASTERN WASHINGTON; THIS TREND CONTINUES INTO THE OVERNIGHT HOURS. THAT SAID, GUIDANCE STILL PROJECTS A CHANCE FOR SOME LINGERING ISOLATED TO SCATTERED SHOWERS OVERNIGHT INTO EARLY FRIDAY MORNING OVER THE EASTERN MOUNTAINS BUT OVERALL THE REGION LOOKS DRIER ALBEIT ONLY TEMPORARILY. ON FRIDAY ANOTHER SHORTWAVE AND ACCOMPANYING FRONTAL BOUNDARY EMBEDDED IN THE SW FLOW ALOFT SWINGS INTO THE REGION BRINGING ANOTHER ROUND OF WIDESPREAD SHOWERS ACROSS THE CWA AND POTENTIAL T-STORMS AS WELL. COMPARED TO TODAY(THURSDAY), THE ENVIRONMENT DOESNT LOOK AS CONDUCIVE FOR CONVECTIVE DEVELOPMENT WITH NOTICEABLY LOWER CAPE VALUES PROJECTED BY THE GFS/NAM. HOWEVER A RUMBLE OF THUNDER OR TWO CANT BE RULED OUT IN STRONGER SHOWER ACTIVITY, MAINLY OVER THE EASTERN MOUNTAINS. ACTIVE AND UNSETTLED WEATHER CONTINUES THROUGH THE WEEKEND BEFORE A RIDGE OF HIGH PRESSURE FINALLY PROGRESSES INTO THE REGION EARLY NEXT WEEK USHERING IN THE RETURN OF DRY AND CALMER CONDITIONS. 99 PREV DISCUSSION... /ISSUED 244 PM PDT THU JUN 2 2022/ SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...SHOWERS AND THUNDERSTORMS ARE INCREASING IN COVERAGE ACROSS THE SOUTHERN HALF OF EASTERN OREGON AND ALONG THE CASCADES THIS AFTERNOON. NOTHING SEVERE AT THIS TIME, BUT ECHO TOPS ARE PUSHING 32K FEET SO UPDRAFTS ARE FAIRLY DECENT. STORMS ARE MOVING AROUND 15-17 KTS AND FFMP IS SHOWING ESTIMATED RAINFALL RATES OF 1-2 INCHES PER HOUR. HOWEVER, THE INSTANTANEOUS PRECIPITATION RATE AND OHA SHOWS A FEW CELLS THAT MAY HAVE BROUGHT 0.5-0.7 INCHES. FLASH FLOOD WATCHES HAVE BEEN ISSUED FOR THE BLUE MOUNTAINS AND THE OREGON PORTION OF THE BLUE MTN FOOTHILLS. TRAINING STORMS AND SLOW MOVEMENT OF STORMS MAY OCCUR IN THIS AREA THAT EXPERIENCED HEAVY RAIN AND FLOODING LAST WEEKEND. DEBRIS FLOWS ARE ALSO POSSIBLE IN THE BURN SCAR AREAS OF ELBOW CREEK AND GREEN RIDGE FIRES FROM 2021. THE SHORTWAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL TRAVEL INTO NORTHERN ID TONIGHT WITH PRECIPITATION TAPERING OFF. HOWEVER, ANOTHER SHORTWAVE AND WEAK FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ON FRIDAY. BASED ON VARIOUS HREF PARAMETERS SUCH AS PAINTBALL REFLECTIVITY > 40 DBZ AND THE QPF ENSEMBLE, SOME STORMS COULD BRING HEAVY RAIN OF 0.5 INCH, MAINLY IN THE BLUE MOUNTAINS, GRANDE RONDE VALLEY, AND WALLOWA COUNTY. HOWEVER, THE STEERING FLOW WILL INCREASE AND LIMIT THE POTENTIAL FOR TRAINING STORMS OR SLOW STORM MOVEMENT AND THE FLASH FLOOD THREAT IS NOT AS HIGH AS TODAY. THE STRONG LOW OFFSHORE WILL SEND ANOTHER SHORTWAVE EAST OF THE CASCADES FRIDAY NIGHT AND SATURDAY. THERE WILL BE EXTENSIVE CLOUD COVER AND THE THREAT OF ANY THUNDERSTORMS IS MINIMAL. HOWEVER, THERE WILL BE NUMEROUS SHOWERS FOR ANOTHER UP TO 0.25 INCH OF ADDITIONAL RAIN IN MANY AREAS, LOCALLY 0.25-0.5 INCH IN THE NORTHEAST MOUNTAINS. WISTER/85 LONG TERM...SUNDAY THROUGH THURSDAY...THE LONG TERM CONTINUES THE PERIOD OF WET WEATHER AS A SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE INLAND NORTHWEST. THUNDERSTORM CHANCES LOOK BETTER THAN SATURDAY, THOUGH AT THIS TIME THEY SHOULD NOT PRESENT A NOTABLE SEVERE RISK. RATHER, CONTINUING THE RISK FOR HEAVY RAINFALL, PRECIPITATION AMOUNTS BETWEEN 0.25-0.75 INCH WIDESPREAD ARE EXPECTED, WITH LOCALLY HEAVIER AMOUNTS IN STRONGER DOWNPOURS AND STORMS. THIS WILL CONTINUE THE FLOOD RISK FOR THE CWA AS ALREADY SATURATED REGIONS SEE MORE PRECIPITATION. INTO MONDAY A RIDGE WILL BEGIN TO DEVELOP OVER THE REGION, WHICH SHOULD HELP END SUBSTANTIAL PRECIPITATION FOR THE FORECAST AREA AND ALLOW TEMPERATURES TO BEGIN WARMING. ENSEMBLE CLUSTER ANALYSIS DOES REVEAL MOSTLY UNANIMOUS AGREEMENT ON A WARMER AND DRIER PERIOD, THOUGH A VERY LOW AMOUNT OF OUTLIERS EXPECT THIS RIDGE WILL NOT BE AS STRONG AS FORECAST. DETERMINISTIC GUIDANCE DOES SHOW A SHORTWAVE APPROACHING THE PACNW COASTLINE ON WEDNESDAY WHICH COULD BRING SOME MOUNTAIN SHOWERS AS WELL AS CLOUD COVER TO THE FORECAST AREA, BUT NONETHELESS IT IS UNLIKELY TO PRODUCE ANY NOTEWORTHY IMPACTS. AND BY THE END OF THE FORECAST PERIOD, HIGH PRESSURE HAS RE-ESTABLISHED ITSELF YET AGAIN, THOUGH MORE SOUTHWESTERLY FLOW MAY BEGIN WHICH COULD BRING MORE MOISTURE TO THE REGION JUST BEYOND THE FORECAST PERIOD. GOATLEY/87 && .AVIATION...06Z TAFS... ANTICIPATE GENERALLY VFR CONDITIONS THROUGH THE TAF PERIOD. SHOWERS HAVE LARGELY COME TO AN END THIS EVENING WITH ANY LINGERING ACTIVITY OVERNIGHT INTO EARLY FRIDAY PINNED NEAR THE HIGHER TERRAIN FEATURES LIKE THE BLUE MTNS AWAY FROM THE LOCAL TAF SITES. AS FRIDAY PROGRESSES SHOWER ACTIVITY LIKELY REGENERATES, INCREASING MOST NOTICEABLY DURING THE LATE AFTERNOON INTO THE EVENING AT DLS, RDM/BDN, PDT, AND ALW AS A FRONTAL BOUNDARY MOVES THROUGH THE AREA. THE BEST CHANCES FOR T-STORMS SHOULD REMAIN CLOSER TO THE BLUE MTNS FRIDAY AFTERNOON BUT A RUMBLE OF THUNDER OR TWO AT PDT/ALW CANT BE RULED OUT. ANY STRONGER SHOWER ACTIVITY COULD BRIEFLY DROP CONDITIONS TO MVFR, MAINLY LATE IN THE PERIOD AND AT RDM/BDN, PDT, AND ALW. EXPECT WINDS TO BE BREEZY FRIDAY AFTERNOON AS WELL WITH GUSTS AROUND 20-25KTS POSSIBLE MOST SITES. 99 && .PRELIMINARY POINT TEMPS/POPS... PDT 55 72 51 66 / 70 60 60 60 ALW 59 77 54 69 / 70 60 50 70 PSC 62 81 57 72 / 50 40 50 40 YKM 56 76 51 71 / 50 50 40 30 HRI 58 78 54 71 / 50 40 60 50 ELN 54 72 49 68 / 60 60 30 30 RDM 50 70 47 67 / 40 20 70 50 LGD 51 70 49 63 / 70 90 60 80 GCD 49 74 50 66 / 60 70 60 80 DLS 60 73 52 71 / 50 50 50 50 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. &&