AFDPDT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 1007 PM PDT WED APR 6 2022 .UPDATED AVIATION DISCUSSION...06Z TAFS... VFR CONDITIONS CURRENTLY AT ALL TAF SITES. WINDS HAVE CALMED TO 10KTS AND BELOW, CIGS ARE 25KFT AND VIS IS P6SM ACROSS ALL TAFS. NO REAL CHANGE FROM PREVIOUS DISCUSSION AS THE FORECAST PERIOD WILL BE CALM AS WE ARE UNDER THE RIDGE. A FEW DIFFERENT MODELS ARE SHOWING A QUICK UPTICK IN THE WINDS FOR KRDM/KBDN FROM 23Z-01Z WHERE THEY ARE PICKING UP SOME GUSTS AT AROUND 15KTS. OTHERWISE, A CALM FORECAST PERIOD AHEAD. .EVENING UPDATE...NO CHANGES FROM PREVIOUS FORECAST SO JUST A RECAP. ECMWF/NAM/GFS AND A FEW OTHER MODELS ARE SHOWING THE AXIS OF THE HIGH PRESSURE RIDGE SITTING OVER OF THE CASCADES CURRENTLY. CLEAR SKIES AND WARM CONDITIONS EXPECTED WITH THE RIDGE, ESPECIALLY AS IT AMPLIFIES OVERNIGHT. DUE TO THE AMPLIFICATION, EXPECT ABOVE NORMAL TEMPERATURES THURSDAY OF 60S IN THE MOUNTAINS AND MID 70S FOR THE REMAINING REGIONS. THE NBM 4.1 IS HINTING THAT PARTS OF CENTRAL OREGON COULD SEE THE LOW 80S TOMORROW. UNFORTUNATELY, THE WARM TEMPERATURES DO NOT LAST VERY LONG AS ON FRIDAY ANOTHER LOW PRESSURE TROUGH MOVES IN FROM THE GULF OF ALASKA. WE WILL THEN SEE NORTHWESTERLY FLOW WHICH WILL USHER IN A COLD AIR MASS/COLD FRONT AHEAD OF THE TROUGH FRIDAY MORNING BRINGING THE TEMPERATURES DOWN TO THE MID 50S AND 60S FOR FRIDAY. THIS TROUGH APPEARS TO BE RELATIVELY DRY AND ONLY THE CRESTS OF THE CASCADES WILL SEE ANY PRECIPITATION ON FRIDAY PRIMARILY DUE TO OROGRAPHIC LIFT. THIS COLD FRONT DOES HOWEVER, BRING THE SNOW LEVELS DOWN TO AROUND 2KFT BY FRIDAY NIGHT SO ANY PRECIPITATION THAT FALLS ACROSS THE MOUNTAINS WILL BE SNOW OR A RAIN SNOW MIX. LAST BUT NOT LEAST, THE SURFACE GRADIENTS DO STRENGTHEN WITH THE ONSET OF THE FRONT WHICH MEANS THAT THERE WILL BE LOCALLY BREEZY CONDITIONS THROUGHOUT THE REGION ON FRIDAY AND INTO SATURDAY. BENNESE/90 PREV DISCUSSION... /ISSUED 236 PM PDT WED APR 6 2022/ SHORT TERM...TONIGHT THROUGH FRIDAY...CLEAR SKIES AND DRY, CALM CONDITIONS AT THE SURFACE HAVE PERSISTED THROUGH EARLY THIS AFTERNOON AS UPPER LEVEL RIDGING CONTINUES TO BUILD OVER THE REGION. THE UPPER LEVEL RIDGE WILL CONTINUE TO AMPLIFY OVER THE REGION THROUGH TOMORROW AS DRY CONDITIONS PERSIST. AT THE SURFACE, WEAK THERMAL TROUGHING UNDER THE RIDGE ALOFT WILL HELP TO PUSH WARMER AIR INTO THE REGION, WITH TEMPERATURES JUMPING INTO THE UPPER 60S TO 70S TOMORROW AFTERNOON. LATE THURSDAY, THE UPPER RIDGE AXIS WILL SHIFT EAST OF THE PACNW AS AN UPPER TROUGH AND SURFACE FRONTAL SYSTEM IN THE NE PACIFIC APPROACHES THE REGION. FRIDAY, THE FRONTAL SYSTEM WILL PUSH A MODERATE STRENGTH, BUT DRY, COLD FRONT ACROSS THE PACNW AND THE FORECAST AREA. SURFACE PRESSURE GRADIENTS WILL TIGHTEN AHEAD OF THE FRONTAL PASSAGE EARLY FRIDAY AND PERSIST INTO THE EXTENDED PERIOD, RESULTING IN BREEZY TO LOCALLY GUSTY WEST WINDS EAST OF THE CASCADES IN OR AND WA. CURRENT GUIDANCE DOES INDICATE THE POTENTIAL FOR WIND GUSTS 45 TO 50 MPH ACROSS PORTIONS OF THE BASIN, GORGE, AND BLUE MTN FOOTHILLS AS A 40-45KT 850MB JET SETS UP OVER THESE AREAS DURING THE DURATION OF THE COLD FRONT PASSAGE. SNOW AND RAIN SHOWERS ARE EXPECTED TO BEGIN LATE THURSDAY NIGHT IN THE CASCADES THEN SPREAD TO THE NORTHEAST MOUNTAINS DURING THE DAY FRIDAY AS THE SYSTEM TRANSITS THE AREA. SNOW LEVELS WILL START OFF ABOVE 7KFT ACROSS THE FORECAST AREA EARLY FRIDAY MORNING, THEN PLUMMET TO 2KFT TO 3KFT BY THE EVENING AS THE UPPER TROUGH FILTERS IN A COLDER AIRMASS ACROSS THE REGION. BY FRIDAY EVENING, ANY LINGERING RAIN SHOWERS WILL TRANSITION OVER TO SNOW SHOWERS IN THE MOUNTAINS, AND WILL PERSIST OVERNIGHT INTO THE WEEKEND. OTHERWISE, THE LOWER ELEVATIONS WILL STAY MAINLY DRY AS RAIN SHADOWING WILL BE FAIRLY PRODUCTIVE EAST OF THE CASCADES. FRIDAY WILL ALSO SEE A COOLING TREND WITH TEMPERATURES MAINLY IN THE MID 50S TO 60S IN THE AFTERNOON. LAWHORN/82 LONG TERM...SATURDAY THROUGH TUESDAY...THE LONG TERM WILL BE CHARACTERIZED BY COOL TO COLD TEMPERATURES UNDER BROAD TROUGHING WITH MOSTLY MOUNTAIN PRECIPITATION IN THE FORM OF SNOW, THOUGH SOME LOWER ELEVATIONS MAY SEE RAIN AND SOME SNOW MIX AS WELL. BEGINNING SATURDAY MORNING IN A POST-FRONTAL ENVIRONMENT, NORTHWESTERLY FLOW ALOFT WILL BE PRESENT ACROSS THE FORECAST AREA, BRINGING A COOLING TREND WHICH WILL DROP US BACK TO MORE WINTER- LIKE TEMPERATURES WITH THE COLDEST CONDITIONS ON SUNDAY AS HIGHS ONLY MAX IN THE LOW 50`S EXCEPT FOR THE COLUMBIA BASIN WHERE MID 50`S WILL BE POSSIBLE. LOWS SUNDAY NIGHT INTO MONDAY SHOULD BRING US FREEZING TEMPERATURES EXCEPT FOR ONCE AGAIN THE COLUMBIA BASIN WHICH WILL TOE THE LINE NEAR 32. INTO MONDAY THE NEXT SYSTEM FROM THE GULF OF ALASKA DROPS ACROSS THE REGION, WITH DETERMINISTIC MODELS STILL STRUGGLING TO HANDLE THE PATH OF THIS FEATURE. WHAT MAKES THIS EVEN MORE INTERESTING IS AT THE END OF THE LONG TERM PERIOD, THE ECMWF BRINGS ANOTHER CUTOFF LOW TOWARDS THE PACNW BUT STALLS IT JUST NORTHWEST ALONG THE CANADIAN COASTLINE, WHEREAS THE GFS HAS RIDGING STATIONED OVER THE WEST COAST. ENSEMBLE ANALYSIS REVEALS NO CLEAR WINNER AS SEVERAL CLUSTERS SHOW EITHER SCENARIO AS POSSIBLE, MAKING THE END OF THE FORECAST PERIOD A BIT UNCERTAIN. NONETHELESS, BELOW AVERAGE TEMPERATURES UNDER NORTHWESTERLY FLOW WILL OCCUR THIS WEEKEND, WITH A SLIGHT WARMING TREND INTO NEXT WEEK EXPECTED, AND MOUNTAIN SNOW THAT COULD APPROACH ADVISORY CRITERIA LATE THIS WEEK INTO THE WEEKEND WITH ANOTHER ROUND OF PRECIPITATION EARLY NEXT WEEK THAT MAY BRING SOME LIGHT RAIN AND POSSIBLE SNOW MIX INTO THE LOWER ELEVATIONS. GOATLEY/87 && .PRELIMINARY POINT TEMPS/POPS... PDT 34 71 44 64 / 0 0 0 10 ALW 37 73 48 66 / 0 0 0 10 PSC 37 71 47 69 / 0 0 0 0 YKM 32 68 45 64 / 0 0 0 10 HRI 36 71 45 66 / 0 0 0 0 ELN 34 66 43 56 / 0 0 0 10 RDM 31 80 42 62 / 0 0 0 0 LGD 33 66 43 65 / 0 0 0 10 GCD 34 73 43 69 / 0 0 0 10 DLS 39 72 48 61 / 0 0 0 20 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. &&