672
FXUS66 KSEW 150405
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
905 PM PDT TUE JUL 14 2026
UPDATE
SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES OVER WESTERN
WASHINGTON THIS EVENING WITH SOME THIN UPPER LEVEL SMOKE/HAZE.
HIGH IN SEATTLE TODAY OF 85 DEGREES WAS ONLY 6 DEGREES OFF THE
RECORD HIGH AND THE TIED FOR THE 7TH WARMEST JULY 14TH IN 82
YEARS OF RECORDS.
LOW LEVEL FLOW WEAKLY ONSHORE TONIGHT. THIS WILL PRODUCE SOME
STRATUS ALONG THE COAST LATER TONIGHT. THE STRATUS WILL TRY AND
MOVE INLAND BUT WITH THE ONSHORE FLOW SO WEAK NOT EXPECTING THE
STRATUS TO GET EAST OF PUGET SOUND, JUST MAINLY ALONG THE COAST
AND THROUGH THE STRAIT OF JUAN DE FUCA. STRATUS DISSIPATING
BEFORE NOON MAKING FOR ANOTHER SUNNY DAY ACROSS THE AREA.
TEMPERATURES PRETTY SIMILAR TO TODAY WITH HIGHS IN THE 60S ON
THE COAST AND MID 70S TO UPPER 80S OVER THE INTERIOR.
CHANGES STILL IN STORE FOR WEDNESDAY NIGHT AND THURSDAY. FIRST
LOOK AT 00Z MODELS SHOWS TWO POSSIBLE WAVES OF CONVECTION. THE
FIRST OVER THE SOUTHERN PORTION OF THE AREA THURSDAY MORNING.
THE SECOND OVER THE CASCADES, ESPECIALLY THE NORTH CASCADES, IN
THE AFTERNOON. A FIRE WEATHER WATCH IS UP FOR THE MOUNTAINS FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR LIGHTNING AND
GUSTY OUTFLOW WINDS. INCREASING LOW LEVEL ONSHORE FLOW THURSDAY
COMBINED WITH POSSIBLE CONVECTION COOLING HIGH TEMPERATURES
OVER THE INTERIOR INTO THE 70S. CURRENT FORECAST ON TRACK. NO
UPDATE THIS EVENING. PREVIOUS DISCUSSION FOLLOWS WITH UPDATED
AVIATION SECTION. FELTON
SYNOPSIS
WARM AND DRY CONDITIONS THROUGH WEDNESDAY WITH HIGH PRESSURE OVER
WESTERN WASHINGTON. WIDESPREAD SHOWERS AND THE THREAT FOR
THUNDERSTORMS RETURNS THURSDAY WITH A LOW PRESSURE SYSTEM. THE LOW
PRESSURE SYSTEM WILL EXIT THE REGION THIS WEEKEND, ALLOWING
HIGH PRESSURE TO BUILD OVER WESTERN WASHINGTON NEXT WEEK,
BRINGING DRIER AND WARMER TEMPERATURES.
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/
LATEST SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES ACROSS WESTERN
WASHINGTON THIS AFTERNOON WITH HIGH PRESSURE CONTINUING TO KEEP
THE REGION WARM AND DRY. EXPECT THESE CONDITIONS TO CONTINUE
THROUGH WEDNESDAY. HIGH TEMPERATURES THROUGH WEDNESDAY WILL BE
IN IN THE MID TO UPPER 60S ALONG THE COAST AND 80S IN THE
INTERIOR. A LOW PRESSURE SYSTEM SPINNING OFF THE PACIFIC OCEAN
WILL SLOWLY START TO MOVE INLAND LATE WEDNESDAY NIGHT/EARLY
THURSDAY MORNING. SOUTHWESTERLY FLOW ALOFT WILL INTRODUCE THE
THE THREAT FOR THUNDERSTORMS TO THE REGION. ON WEDNESDAY,
THUNDERSTORM POTENTIAL WILL BE MOSTLY LIMITED TO THE HIGHER
TERRAIN OF THE CASCADES WITH A 10-20% CHANCE FOR THUNDERSTORMS
AND HIGHEST CHANCES IN THE VICINITY OF MOUNT RAINIER. AS FOR
THURSDAY, THE THREAT FOR MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS CONTINUES TO INCREASE. LATEST MODEL GUIDANCE
SUGGESTS A 20-25% CHANCE FOR THUNDERSTORMS. HOWEVER, SOME
UNCERTAINTY REMAINS REGARDING THUNDERSTORM COVERAGE AND EXACT
RAINFALL AMOUNTS. ANY THUNDERSTORM THAT DOES DEVELOP MAY PRODUCE
DANGEROUS LIGHTNING, GUSTY/ERRATIC WINDS, SMALL HAIL, AND BRIEF
HEAVY DOWNPOURS. THUNDERSTORM ACTIVITY WILL SLOWLY SUBSIDE LATE
THURSDAY NIGHT. 29
LONG TERM /FRIDAY THROUGH TUESDAY/
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL SLOWLY BEGIN TO PUSH OUT
OF THE REGION FRIDAY INTO SATURDAY. THIS WILL ALLOW A BROAD UPPER
LEVEL RIDGE TO START BUILDING OVER WESTERN WASHINGTON WITH ENSEMBLE
GUIDANCE SUGGESTING THE RIDGE WILL BE OVER THE REGION EARLY
NEXT WEEK. THIS WILL SET UP A DRY AND MUCH WARMER WEATHER
PATTERN. GUIDANCE SUGGESTS TEMPERATURES WILL PEAK IN THE MID TO
UPPER 60S TO LOW 70S ALONG THE COAST AND 80S TO LOW 90S ALONG
THE INTERIOR. AS A RESULT, THIS WILL BRING AREAS OF MODERATE
HEATRISK TO MOST OF THE REGION AND A 20-50% CHANCE FOR MAJOR
HEATRISK BY TUESDAY ACROSS PORTIONS OF WESTERN WASHINGTON.
29
AVIATION
WIDESPREAD VFR CONDITIONS WILL CONTINUE THROUGHOUT THE EVENING HOURS
FOR ALL TERMINALS. THE EXCEPTION IS KHQM, WHERE A MIX OF MVFR/IFR
EARLY WEDNESDAY MORNING STARTING AT AROUND 07Z-09Z. MARINE STRATUS
LOOKS TO HANG AROUND ALONG THE COAST THROUGHOUT THE MORNING AND
EARLY AFTERNOON, BEFORE BURNING OFF LATE AFTERNOON/EARLY EVENING.
N/NE WINDS 5 TO 10 KNOTS SHIFTING MORE SW THIS EVENING BEFORE
TRANSITIONING TO NW BY 15Z-17Z WEDNESDAY MORNING.
KSEA...VFR CONDITIONS WILL CONTINUE THROUGHOUT THE TAF PERIOD. N/NW
WINDS 5 TO 8 KNOTS SHIFTING MORE SW LATE TONIGHT INTO EARLY
WEDNESDAY MORNING, STAYING LIGHT. WINDS WILL THEN RETURN TO NW AND
STAY AROUND 4 TO 8 KNOTS THROUGH WEDNESDAY AFTERNOON.
MAZURKIEWICZ/21
MARINE
SURFACE HIGH PRESSURE OFFSHORE WILL BE REPLACED BY AN OFFSHORE LOW
APPROACHING THE WATERS. DIURNALLY DRIVEN WESTERLIES WILL CONTINUE
DOWN THE STRAIT OF JUAN DE FUCA, WITH WINDS REMAINING UNDER ANY
SMALL CRAFT ADVISORY THRESHOLDS FOR THE NEXT COUPLE OF DAYS. THE
COASTAL WATERS MAY SEE A FEW WIND GUSTS UP TO 20 KTS ON THURSDAY AND
FRIDAY AS THE LOW PRESSURE SYSTEM TRACKS THROUGH THE WATERS. A MORE
SUMMERTIME PATTERN WILL RETURN THIS WEEKEND AND EARLY NEXT WEEK,
WITH MORE WESTERLY PUSHES DOWN THE STRAIT OF JUAN DE FUCA.
COASTAL SEAS REMAIN AT 4 TO 6 FEET THROUGH MIDWEEK, WITH SEAS
SLIGHTLY INCREASING TO 7 TO 8 FEET WITH PERIODS OF 6 TO 8 SECONDS.
MAZURKIEWICZ
FIRE WEATHER
WARM TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH WEDNESDAY, WITH
MINIMUM RELATIVE HUMIDITY VALUES DIPPING INTO THE UPPER 20% TO LOW
30% THROUGHOUT WESTERN WASHINGTON. AN ELEVATED FIRE WEATHER PATTERN
WILL SET UP LATE WEDNESDAY AND LIKELY CONTINUE THROUGH EARLY NEXT
WEEK. SHOWERS AND THUNDERSTORMS RETURN TO THE FORECAST AS EARLY AS
LATE WEDNESDAY NIGHT THROUGH THURSDAY. THE MAIN CONCERNS WITH THESE
STORMS WILL BE DRY LIGHTNING AND THE POTENTIAL FOR STRONG OUTFLOWS
BETWEEN 35-50 MPH. STORMS THAT DEVELOP ON THE WEST SLOPES OF THE
OLYMPICS ARE MORE LIKELY TO PRODUCE A WETTING RAIN (0.25 INCHES),
WHILE STORMS ALONG THE CASCADES WILL PRODUCE SUB-WETTING RAIN
AMOUNTS OF 0.10-0.20 INCHES. FIRE WEATHER CONCERNS LINGER INTO EARLY
NEXT WEEK AS A HOTTER AND DRIER PATTERN SETS UP OVER WESTERN
WASHINGTON, POTENTIALLY INCREASING FIRE ACTIVITY FROM ANY NEW
LIGHTNING STARTS FROM THURSDAY'S CONVECTION.
29
SEW WATCHES/WARNINGS/ADVISORIES
WA...FIRE WEATHER WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
EVENING FOR EAST PORTION OF THE OLYMPIC MOUNTAINS-WEST
PORTION OF THE OLYMPIC MOUNTAINS-WEST SLOPES OF THE
CENTRAL CASCADES GENERALLY ABOVE 1500 FEET-WEST SLOPES OF
THE NORTH CASCADES GENERALLY ABOVE 1500 FEET.
PZ...NONE.
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