000 FXUS66 KPQR 071606 AFDPQR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PORTLAND OR 904 AM PDT THU APR 07 2005 .SYNOPSIS...A WEAKENING COLD FRONT ALONG THE COAST THIS MORNING WILL MOVE EAST ACROSS THE FORECAST AREA TODAY...USHERING IN A COOLER UNSTABLE AIR MASS. LOW PRESSURE FROM THE GULF OF ALASKA WILL DROP SOUTHEAST TOWARDS THE OREGON COAST TONIGHT AND FRI...DRIVING ANOTHER FRONTAL SYSTEM THROUGH. AN UPPER RIDGE WILL BUILD UP FROM THE SOUTHWEST SAT...AND SHIFT INTO EASTERN OREGON SUN. ANOTHER FRONTAL SYSTEM IS EXPECTED TO COME IN EARLY NEXT WEEK. && .SHORT TERM...SATELLITE SHOWS UPPER TROUGH ALONG THE COAST WITH A SLIGHT NEGATIVE TILT...WITH VORTICITY LOBE LIFTING NORTH ACROSS THE AREA THIS MORNING AIDING PRECIPITATION WITH THE SLOW MOVING FRONTAL ZONE. SHOULD BE A TRANSITION INTO A MORE SHOWERY PATTERN THIS AFTERNOON AS COLDER AIR ALOFT MOVES IN AND FLOW TURNS MORE ONSHORE AIDING OROGRAPHICS. WILL HANG ONTO A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON AS -28C COOL POOL AT 500 MB LIFTS ACROSS THE AREA. 850MB FLOW TODAY DOES NOT APPEAR AS STRONG AS IN PREVIOUS RUNS...SO EXPECT SNOWFALL IN CASCADES TO REMAIN BELOW ADVISORY CRITERIA. MODELS SHOW A POTENTIALLY STRONGER SYSTEM MOVING INTO THE AREA FROM THE GULF OF AK TONIGHT AND FRI. BEST POPS TO BE FOUND OVER THE SOUTHERN PART OF THE FORECAST AREA LATER TONIGHT AND FRI AS MODELS ARE TENDING TO DROP DYNAMICS A LITTLE FURTHER S THAN EARLIER RUNS. ALL MODELS ARE NOW GOING WITH A CLOSED LOW AS IT APPROACHES THE CENTRAL OREGON COAST FRI MORNING...WITH GFS AND CANADIAN INDICATING THE DEEPEST LOWS. WILL NEED TO BUMP UP WINDS SOME...ESPECIALLY ALONG THE CENTRAL OREGON COAST. FLOW DIMINISHES FRI NIGHT AND SAT AS UPPER TROUGH SHIFT E... INDICATING A DIMINISHING THREAT FOR SHOWERS AS ONSHORE FLOW SLOWLY WEAKENS. WILLIS .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... EXTENDED MODELS TEND TO KEEP A MODERATELY PROGRESSIVE PATTERN GOING THROUGH THE EXTENDED...BUT QUICKLY BECOME INCONSISTENT BOTH BETWEEN MODELS AND RUN TO RUN WITH TIMING OF KEY FEATURES AFTER THIS WEEKEND. AS SUCH...WILL NEED TO KEEP A BROAD-BRUSHED APPROACH TO THE FORECAST...INDICATING CHANCES FOR SHOWERS EACH DAY. && .PRELIMINARY POINT POPS AST 96764 PDX 86664 SLE 86864 EUG 86864 && .PQR WATCHES/WARNINGS/ADVISORIES... .OR/WA...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO FLORENCE THROUGH THIS EVENING. GALE WARNING FROM MIDNIGHT THROUGH FRI MORNING CAPE SHOALWATER TO CASCADE HEAD. .OR......GALE WARNING FROM MIDNIGHT THROUGH FRI CASCADE HEAD TO FLORENCE. $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND