AFDSEW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 813 PM PST THU FEB 15 2024 .SYNOPSIS...AN UPPER LEVEL TROUGH WILL CONTINUE TO DRIFT EASTWARD TONIGHT, ALLOWING DRIER AIR TO MOVE INTO THE REGION AS SHOWERS TAPER DOWN FOR THE NIGHT. A WEAK RIDGE WILL AMPLIFY INTO WESTERN WASHINGTON ON FRIDAY, ALLOWING TEMPERATURES TO MODERATE AND WARM UP. SOUTHERLY FLOW WILL INTRODUCE SOMEWHAT MILDER CONDITIONS THIS WEEKEND ALONG WITH A RETURNING CHANCE OF SOME PRECIPITATION. UNSETTLED CONDITIONS WILL PERSIST INTO EARLY NEXT WEEK. && .SHORT TERM /TONIGHT THROUGH SUNDAY/...ONLY MINOR EDITS TO THE FORECAST THIS EVENING TO REFLECT ELEVATED WINDS IN THE CASCADE FOOTHILLS STARTING TOMORROW AFTERNOON. OTHERWISE, IT ALL REMAINS ON TRACK AND THE PREVIOUS DISCUSSION CAN BE FOUND BELOW WITH AN UPDATE TO THE AVIATION AND MARINE SECTIONS. SHOWER ACTIVITY WILL CONTINUE TO WIND DOWN TONIGHT AS AN UPPER LEVEL TROUGH SHIFTS TOWARDS THE EAST AND DRIER AIR IS ADVECTED INLAND. THE REMNANTS OF A STALLED FRONTAL BOUNDARY WILL MAINTAIN A LOW CHANCE OF LIGHT PRECIPITATION ACROSS FAR SOUTHERN WASHINGTON FRIDAY MORNING AS THE REST OF THE REGION DRIES OUT. A TROUGH WILL SLOWLY APPROACH THE SHORE ON FRIDAY, SHARPENING THE PRESSURE GRADIENT AND ENHANCING EASTERLY MOUNTAIN GAP WINDS. HIGH RESOLUTION ENSEMBLE MEAN SHOWS UP TO 60 MPH GUSTS POSSIBLE ACROSS SOME OF THE KING AND SNOHOMISH CASCADE FOOTHILLS FRIDAY AFTERNOON, WITH A HIGH (50 TO 70 PERCENT) CHANCE OF GUSTS ABOVE 50 MPH THROUGH THE EVENING ALONG THE I-90 CORRIDOR. THE STRONGEST WINDS WILL OCCUR BETWEEN SNOQUALMIE AND ENUMCLAW, BUT GUSTY GAP WINDS WILL EXTEND AS FAR NORTH AS SNOHOMISH, IMPACTING THE US-2 CORRIDOR. A WIND ADVISORY HAS BEEN ISSUED FOR THESE AREAS STARTING FRIDAY MORNING AND CONTINUING THROUGH SATURDAY MID-DAY. A WARM FRONT LIFTING NORTHWARD OVER THE OFFSHORE WATERS WILL BRING A RETURNING CHANCE OF RAINFALL TO THE OLYMPIC PENINSULA BY LATE FRIDAY AFTERNOON. PRECIPITATION WILL GRADUALLY INCREASE ACROSS ALL OF WESTERN WASHINGTON INTO SATURDAY AS A BROAD UPPER TROUGHING EDGES CLOSER. A COUPLE OF FRONTS WILL ATTEMPT TO MOVE ONSHORE, BUT LOOK TO ULTIMATELY STALL OR FALL APART AS BETTER JET STREAM SUPPORT WILL REMAIN WELL SOUTH OF THE REGION THROUGH SATURDAY. PRECIPITATION AMOUNTS WILL BE LIGHT, WITH WARMER TEMPERATURES ALLOWING SNOW LEVELS TO STAY NEAR OR ABOVE 4000 FT. .LONG TERM /MONDAY THROUGH THURSDAY/...ACTIVE WEATHER WILL CONTINUE INTO THE REMAINDER OF THE WEEKEND AND NEXT WEEK AS BROAD UPPER LEVEL TROUGHING CONTINUES ALONG THE PACIFIC COAST. WESTERN WASHINGTON WILL REMAIN ON THE NORTHERN PERIPHERY OF THE ACTIVITY FOR PERIODIC LIGHT PRECIPITATION, BUT THE UPPER LEVEL JET WILL LIMIT THE MAJORITY OF THE IMPACTFUL WEATHER SOUTHWARD TO CALIFORNIA. BY THE MIDDLE PART OF NEXT WEEK, ENSEMBLES ARE BEGINNING TO SHOW SOME WEAKLY POSITIVE HEIGHT ANOMALIES. WHILE NOT INDICATIVE OF AN ENTIRELY DRY FORECAST, THIS WOULD SUGGEST THAT NO IMPACTFUL WEATHER OF NOTE IS ON THE HORIZON AS WE ROUND OUT THE THIRD WEEK OF FEBRUARY. LINDEMAN && .AVIATION...LIGHT, VARIABLE WINDS ALOFT TONIGHT INTO FRIDAY MORNING WITH AN UPPER LOW MOVING EASTWARD AND RIDGING STARTING TO BUILD INTO THE AREA. OFFSHORE FLOW CONTINUES AT THE SURFACE. GENERALLY VFR CIGS THIS EVENING WITH AREAS OF MVFR ALONG THE STRAIT OF JUAN DE FUCA AND SOUTH PUGET SOUND. PATCHY LIFR ALSO OBSERVED NEAR KOLM WITH LOWER CIGS. VFR EXPECTED FOR MOST AREAS TONIGHT INTO FRIDAY WITH MID CLOUDS GENERALLY DIMINISHING IN EXTENT TONIGHT AND INCREASING HIGH CLOUDS FRIDAY. PATCHY LIFR CIGS, AND POTENTIAL VSBY REDUCTION, MAY BE OBSERVED THROUGH TONIGHT, MAINLY FOR KOLM AND KPWT. ELSEWHERE, A SLIGHT POTENTIAL OF MVFR CIGS EXISTS IN THE MORNING, BUT THE THREAT IS LIMITED DUE TO DRIER AIR AT THE SURFACE. DRY CONDITIONS LATE TONIGHT AND FRIDAY. GENERALLY EAST WINDS THROUGH FRIDAY, INCREASING FRIDAY AFTERNOON INTO FRIDAY EVENING. KSEA...VFR CIGS THIS EVENING WITH CONTINUED MID LEVEL CLOUDS (3500- 4500 FT) THAT WILL SLOWLY SCATTER TONIGHT. LOW POTENTIAL (20-30% CHANCE) OF MVFR CIGS TONIGHT INTO FRIDAY MORNING. OTHERWISE, INCREASING HIGH CLOUDS EXPECTED ON FRIDAY. E/NE WINDS THROUGH TONIGHT WILL TRANSITION MORE ESE MIDDAY FRIDAY, AND STRENGTHEN INTO FRIDAY EVENING. SUSTAINED ESE WINDS WILL LIKELY INCREASE TOWARDS 10 TO 15 KTS BY FRIDAY AFTERNOON WITH GUSTS RANGING 20 TO 30 KTS INTO FRIDAY NIGHT. JD && .MARINE...A WEAKENED SURFACE LOW PRESSURE CONTINUES TO SIT OFFSHORE IN THE COASTAL WATERS THIS AFTERNOON, MAINTAINING OFFSHORE FLOW ALOFT THROUGH THE AREA WATERS. SMALL CRAFT ADVISORIES CONTINUE THROUGH THE NORTHERN INLAND WATERS, THE CENTRAL STRAIT, AND THE COASTAL WATERS INTO TONIGHT. OFFSHORE GRADIENTS LOOK TO TIGHTEN AND INCREASE AS ANOTHER SURFACE LOW PRESSURE SYSTEM GRADUALLY GETS CLOSER TO THE COAST ON FRIDAY. GALE WARNINGS IN EFFECT FOR THE COASTAL WATERS, AND THE CENTRAL AND WESTERN STRAIT OF JUAN DE FUCA FOR FRIDAY THROUGH FRIDAY NIGHT. THESE WINDS WILL START TO GRADUALLY DECREASE OVER THE WATERS INTO SATURDAY, WHERE ADDITIONAL SMALL CRAFT ADVISORIES MAY BE NEEDED. COMBINED SEAS 5 TO 7 FEET WILL START TO BUILD UPWARDS INTO FRIDAY, AND BE APPROACHING 15 TO 19 FEET BY SATURDAY NIGHT. THE BIGGER OF THE SEAS WILL BE MAINLY IN THE OUTER COASTAL WATER ZONES. JD/MAZ && .HYDROLOGY...NO RIVER FLOODING IS EXPECTED IN THE NEXT SEVEN DAYS. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...WIND ADVISORY FROM 7 AM FRIDAY TO 10 AM PST SATURDAY FOR EAST PUGET SOUND LOWLANDS. PZ...SMALL CRAFT ADVISORY UNTIL 4 AM PST FRIDAY FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS-WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. GALE WARNING FROM 4 AM FRIDAY TO 4 AM PST SATURDAY FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. SMALL CRAFT ADVISORY FROM 10 AM FRIDAY TO 10 AM PST SATURDAY FOR EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. SMALL CRAFT ADVISORY UNTIL 7 AM PST FRIDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM. GALE WARNING FROM 7 AM FRIDAY TO 10 AM PST SATURDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM- COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM- COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. SMALL CRAFT ADVISORY UNTIL 7 AM PST FRIDAY FOR COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM- COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. &&