655 FXUS66 KPDT 191045 AAA AFDPDT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 344 AM PDT TUE MAR 19 2013 UPDATED AVIATION DISCUSSION .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...A WARM FRONT WILL MOVE INTO CENTRAL OREGON TODAY AND SPREAD PRECIPITATION NORTH AND EAST ACROSS THE CWA THIS AFTERNOON. THE PRECIPITATION WILL BE PRIMARILY RAIN AS SNOW LEVELS WILL RISE TO 5000-6000 FEET BY THIS EVENING. BREEZY SOUTHERLY WINDS WILL DEVELOP TONIGHT, PARTICULARLY IN THE SOUTHERN GRANDE RONDE VALLEY. A STRONG COLD FRONT WILL MOVE THROUGH THE AREA WEDNESDAY AFTERNOON AND EVENING. THIS WILL KEEP PRECIPITATION OVER THE AREA. RAIN SHADOWING WILL DEVELOP OVER THE LOWER COLUMBIA BASIN AND DESCHUTES PLATEAU, BUT OROGRAPHIC EFFECTS WILL KEEP POPS HIGH IN THE MOUNTAINS. WINDS WILL BE WINDY TO LOCALLY VERY WINDY BEHIND THE COLD FRONT...ESPECIALLY IN THE COLUMBIA BASIN AND THE FOOTHILLS OF THE BLUE MOUNTAINS. THE UPPER TROUGH SUPPORTING THE FRONT WILL MOVE EAST WEDNESDAY NIGHT WITH DECREASING PRECIPITATION. COONFIELD .LONG TERM...THURSDAY THROUGH MONDAY NIGHT...MODELS ARE BEGINNING TO AGREE WITH A TROUGH OF LOW PRESSURE DROPPING ACROSS THE PACIFIC NORTHWEST FROM THE NORTH THURSDAY INTO FRIDAY. THIS WILL KEEP TEMPERATURES BELOW NORMAL AND SNOW LEVELS WILL REMAIN AROUND 2000-3000 FEET. WITH SOME MOISTURE AND AN UPSLOPE FLOW...THERE WILL REMAIN A CHANCE OF PRECIPITATION IN THE AREA MOUNTAINS THROUGH FRIDAY. MODELS BEGIN TO DIVERGE SATURDAY INTO NEXT WEEK WITH THE GFS SHIFTING THE TROUGH OVER THE ROCKY MOUNTAINS AND LEAVING THE PACIFIC NORTHWEST IN A NORTH FLOW. THE EUROPEAN MODEL MOVES THE TROUGH EASTWARD WITH A RIDGE BUILDING INTO THE REGION. HAVE LEANED TOWARD THE GFS AS IT HAS HAD THE BETTER CONSISTENCY OVER THE LAST FEW DAYS. WITH THE NORTHERLY FLOW...SOME DISTURBANCES MOVING THROUGH IT WILL KEEP A CHANCE OF PRECIPITATION OVER THE AREA THROUGH SUNDAY. SUNDAY NIGHT INTO MONDAY...THE GFS BUILDS THE RIDGE OF HIGH PRESSURE OFF SHORE...PUSHING THE TROUGH FURTHER EAST AND LEADING TO A DRYING AND WARMING TREND. DMH && .AVIATION...12Z TAFS...A WARM FRONT WILL MOVE ACROSS THE AREA TUESDAY AFTERNOON AND EVENING...BRINGING LOWERING CEILINGS AND RAIN TO ALL TAF SITES. WHILE VFR CONDITIONS WILL PREVAIL MOST OF THE DAY...MVFR CONDITIONS ARE POSSIBLE UNDER THE HEAVIER SHOWERS. SURFACE WINDS ARE EXPECTED TO REMAIN LESS THAN 12 KTS THROUGH THE PERIOD...WITH SOME GUSTY WINDS POSSIBLE TUESDAY EVENING FOR KBDN. DMH && .PRELIMINARY POINT TEMPS/POPS... PDT 58 42 60 36 / 10 60 60 30 ALW 59 45 60 39 / 10 60 60 30 PSC 57 43 63 42 / 10 60 40 20 YKM 54 35 58 32 / 20 70 50 20 HRI 58 41 62 36 / 10 60 40 20 ELN 55 35 56 32 / 20 70 50 20 RDM 61 37 54 24 / 50 60 50 20 LGD 50 44 55 34 / 10 70 70 30 GCD 59 38 53 28 / 40 70 60 30 DLS 55 40 56 36 / 40 80 50 20 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && THREAT INDEX TODAY : GREEN WEDNESDAY : YELLOW THURSDAY : GREEN GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES. YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 76/84/84