754
FXUS66 KSEW 231556
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
856 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/
NO SIGNIFICANT CHANGES MADE
TO THE FORECAST THIS MORNING. THE PREVIOUS DISCUSSION CAN BE FOUND
BELOW ALONG WITH AVIATION AND MARINE UPDATES:
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 AXIS OVER THE COASTAL WATERS WILL
SHIFT ONSHORE TONIGHT WITH NORTH TO NORTHWEST FLOW ALOFT BECOMING
LIGHT SOUTHERLY OVERNIGHT. THE LOW LEVEL FLOW REMAINS NORTHERLY. THE
AIR MASS IS DRY AND STABLE. VFR IS EXPECTED AREAWIDE AFTER PATCHY
STRATUS MAINLY NEAR THE COAST DISSIPATES.
KSEA...VFR. SURFACE WINDS BECOMING NORTH/NORTHWESTERLY 5 TO 8 KNOTS
THIS AFTERNOON THEN LIGHT NORTHEASTERLY TONIGHT. 27
MARINE
A SURFACE RIDGE CENTERED OFFSHORE WILL WEAKEN THROUGH
TOMORROW. A BROAD AREA OF WEAK SURFACE LOW PRESSURE WILL DEVELOP
LATE IN THE WEEK OVER THE PACIFIC NORTHWEST WHILE HIGH PRESSURE
REMAINS CENTERED WELL OFFSHORE. THIS WILL LEAD TO AN OVERALL
INCREASE IN ONSHORE FLOW LEADING INTO THE UPCOMING WEEKEND. THE END
RESULT WILL LIKELY BE A PERIOD OF SMALL CRAFT ADVISORY WINDS ACROSS
THE COASTAL WATERS AS WELL AS THE CENTRAL/EAST PORTIONS OF THE
STRAIT. 27
HYDROLOGY
NO RIVER FLOODING IS EXPECTED OVER THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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