614
FXUS66 KSEW 231010
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
310 AM PDT WED APR 23 2025
SYNOPSIS
HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH
THURSDAY, BRINGING IN WARMER AND DRY CONDITIONS. COOLER AND WETTER
WEATHER WILL MOVE IN LATER THIS WEEKEND, WITH CHANCES FOR A
RETURN OF DRIER AND WARMER WEATHER TOWARDS THE LATTER HALF OF NEXT
WEEK.
SHORT TERM /TODAY THROUGH FRIDAY/
A HIGH PRESSURE RIDGE WILL
CONTINUE TO BUILD INLAND THROUGH THURSDAY, BRINGING IN WARMER
TEMPERATURES ALONGSIDE SUNNY AND DRY CONDITIONS. TEMPERATURES
WILL RISE ABOVE NORMAL TODAY AND CONTINUE WARMING INTO THURSDAY,
WITH MOST LOWLAND AREAS EAST AND SOUTH OF THE PUGET SOUND SEEING
HIGHS IN THE 70S ON THURSDAY. CLOUDS WILL SLOWLY START TO INCREASE
FROM THE WEST ON THURSDAY AS A TROUGH SLOWLY APPROACHES THE COAST
AND THE UPPER RIDGE AXIS SHIFTS TO THE EAST OF THE REGION.
FORECAST MODELS REMAIN IN GOOD AGREEMENT OVER A CUTOFF LOW MOVING
INLAND OVER NORTHERN CALIFORNIA ON FRIDAY. TRENDING THE STORM
SYSTEM FURTHER SOUTH, ENSEMBLES HAVE DECREASED THE CHANCES FOR
SHOWER ACTIVITY ACROSS WESTERN WASHINGTON ON FRIDAY. TEMPERATURES
WILL REMAIN WELL ABOVE NORMAL ON FRIDAY UNDER SOUTHERLY FLOW
ALOFT, BUT CLOUDY SKIES WILL LOWER TEMPERATURES A FEW DEGREES FROM
THURSDAY.
LONG TERM /SATURDAY THROUGH TUESDAY/
OPERATIONAL FORECAST
MODELS ARE HINTING AT SPLIT FLOW DEVELOPING ON SATURDAY, WHICH
WOULD KEEP MOST OF THE REGION COOLER AND DRY. CHANCES FOR
PRECIPITATION INCREASE TOWARDS THE END OF THE WEEKEND AS A TROUGH
MOVES OVER THE REGION, BUT MODELS CONTINUE TO SHOW DIFFERENCES
OVER THE TIMING AND INTENSITY OF PRECIPITATION. SHOWERS ARE NOW
FAVORED TO LINGER INTO EARLY NEXT WEEK BEFORE ANOTHER HIGH
PRESSURE RIDGE DEVELOPS OVER THE WESTERN US, BRINGING A RETURN OF
DRIER AND WARMER CONDITIONS.
15
AVIATION
AN UPPER LEVEL RIDGE OFFSHORE WILL MOVE INLAND THIS
EVENING/THURSDAY MORNING (WITH LIGHT NORTHWESTERLY FLOW ALOFT). ALL
TERMINALS ARE VFR AS OF EARLY THIS MORNING. THERE IS A WEAK ONSHORE
GRADIENT THAT MAY BRING SOME LIMITED STRATUS ALONG THE COAST FOR A
SHORT PERIOD THIS MORNING. FOG IS NOT EXPECTED IN THE MORNING (ONLY
A 10% CHANCE OF SEEING ANY NORTH OF SEATTLE ALONG THE I-5 CORRIDOR
IN LOW LYING AREAS). OTHERWISE IT WILL REMAIN VFR IN THE TAF PERIOD
WITH MOSTLY CLEAR SKIES, AND NORTH-NORTHWEST WINDS 5-10 KT.
KSEA...VFR WITH MOSTLY CLEAR SKIES EXPECTED IN THE ENTIRE TAF
PERIOD. WINDS WILL REMAIN LIGHT OUT OF THE NORTHEAST AT 4 TO 8 KT
THIS MORNING, AND SWITCH TO THE NORTHWEST 5 TO 10 KT THIS AFTERNOON.
HPR
MARINE
HIGH PRESSURE OFFSHORE WILL START TO MOVE INLAND THURSDAY,
AND WEAKEN AS IT COMES ASHORE. THE NEXT CHANCE OF A DISTURBANCE
COMES FRIDAY/SATURDAY WITH A TROUGH MOVING TO THE SOUTHWEST OFF OF
OREGON. THIS WILL LIKELY BRING NORTHWEST WINDS SUSTAINED TO 20 KT IN
THE OUTER COASTAL WATERS DURING THIS TIME, BUT OTHERWISE NO IMPACTS
IN REMAINING WATERS THROUGH THE NEXT 7 DAYS (EXCEPT FOR A POSSIBLE
PUSH THROUGH THE STRAIT OF JUAN DE FUCA SATURDAY EVENING).
SEAS WILL REMAIN 5 TO 7 FEET WITH A BRIEF PERIOD OF 8 FOOT WAVES
SATURDAY EVENING.
HPR
HYDROLOGY
NO RIVER FLOODING IS EXPECTED OVER THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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