000 FXUS66 KPDT 151138 AAA AFDPDT AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PENDLETON OR 438 AM PDT SUN JUL 15 2007 UPDATED AVIATION DISCUSSION .SHORT TERM...TODAY THROUGH MONDAY NIGHT...CONDITIONS LOOK TO BE MORE TRANQUIL DURING THE NEXT 36 TO 48 HOURS OVER THE CWA. HOWEVER THE FLOW ALOFT WILL REMAIN FROM THE SOUTH TO SOUTHWEST AS A PERSISTENT UPPER RIDGE REMAINS OVER THE FOUR COVERS REGION AND AN UPPER TROUGH REMAINS OFF THE COAST. THIS FLOW WILL KEEP IT VERY WARM. THERE WILL ALSO BE SOME LIMITED LOW TO MID LEVEL MONSOON MOISTURE AND INSTABILITY. TODAY LOOKS TO BE THE MOST UNSTABLE DAY WITH AREAS IN SOUTHERN PORTIONS OF THE CWA HAVING ISOLATED THUNDERSTORMS THIS AFTERNOON...DECREASING THIS EVENING. AFTER TODAY THE ATMOSPHERE WILL BE MORE STABLE WITH DRIER AIR IN PLACE. THIS WILL RESULT IN MAINLY PARTLY CLOUDY SKIES BECOMING MOSTLY CLEAR BY PERIOD 4. THERE MAY STILL BE A FEW ISOLATED AFTERNOON THUNDERSTORMS OVER THE HIGHEST TERRAIN DUE TO DIURNAL MOUNTAIN INDUCED LIFTING... BUT ELSEWHERE IT WILL REMAIN DRY. BREEZY WINDS WILL BECOME PREVALENT IN THE WESTERN VALLEYS AGAINST THE CASCADE EAST SLOPES AS WELL AS THE EASTERN COLUMBIA RIVER GORGE. THIS WILL RESULT IN COOLER AND MORE STABLE MARINE AIR SPILLING OVER THE CASCADES INTO THE EAST SIDE OF OR/WA TODAY AND MONDAY. TEMPERATURES WILL REMAIN VERY WARM IN THE SOUTHERLY FLOW WITH THE LOWER ELEVATIONS IN THE 90S AND THE MOUNTAINS IN THE MID 70S TO MID 80S. 100 DEGREE TEMPERATURES ARE NOT EXPECTED...EXCEPT PERHAPS A FEW ISOLATED LOCATIONS...MAINLY IN THE LOWER BASIN AND HELLS CANYON. 88 .LONG TERM...TUESDAY THROUGH SATURDAY...DEEP UPPER LEVEL TROUGH WILL BE ALONG THE WEST COAST ON TUESDAY WITH A SOUTH FLOW OVER THE REGION. AT THIS TIME...MAIN MOISTURE TUESDAY LOOKS TO BE WEST OF THE CASCADE CREST. STILL SHOULD BE ENOUGH MOISTURE AND INSTABILITY FOR A STRAY SHOWER OR THUNDERSTORM OVER THE MOUNTAINS THOUGH. LOOKS THAT A STRONG WAVE WILL ROTATE AROUND THE BOTTOM OF THE TROUGH WEDNESDAY THROUGH THURSDAY. THIS SHOULD INCREASE THE MOISTURE AND ENERGY OVER THE REGION...POTENTIALLY LEADING TO MORE WIDESPREAD SHOWERS AND THUNDERSTORMS THAN INDICATED BY CURRENT FORECASTS. FOR NOW STILL ENOUGH UNCERTAINTY ON EXACT TIMING AND STRENGTH TO LEAVE FORECAST AS IS. BY FRIDAY AND SATURDAY...AREA LOOKS TO BE UNDER A MORE WESTERLY AND STABLE ONSHORE FLOW. THUS WILL CONTINUE CURRENT DRY FORECAST. 90 && .AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH THE NEXT 24 HOURS WITH MID AND HIGH LEVEL CLOUDINESS. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING FROM DESCHUTES COUNTY EAST AND NORTHEAST OVER THE OCHOCO...BLUE AND WALLOWA MOUNTAINS. TAF SITE MOST LIKELY TO BE AFFECTED WILL BE KRDM...BUT CHANCES LOOK TO BE LOW SO WILL ONLY INDICATE SOME CB CLOUDS. SMOKE LAYERS FROM FIRES WILL CONTINUE TO IMPACT SOME AREAS. 90 && .PRELIMINARY POINT TEMPS/POPS... PDT 91 63 91 64 / 10 10 10 10 ALW 95 66 95 67 / 10 10 10 10 PSC 95 63 95 64 / 10 0 10 10 YKM 93 62 93 63 / 10 10 10 10 HRI 93 63 93 64 / 10 0 10 10 ELN 93 62 93 63 / 10 10 10 10 RDM 90 53 90 54 / 20 10 10 10 LGD 94 63 94 64 / 10 10 10 10 GCD 92 58 92 59 / 10 10 10 10 DLS 92 65 92 66 / 10 0 10 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && $$ TI:GGG FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON 88/90/90