735
FXUS61 KLWX 220022
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
822 PM EDT MON JUL 21 2025
SYNOPSIS
LOWER RAIN CHANCES AND LOWER HUMIDITY ARE EXPECTED THROUGH THE
MIDDLE OF THE WEEK AS A STRONG AREA OF CANADIAN HIGH PRESSURE
BUILDS TO THE NORTH. A RETURN TO MORE SUMMERTIME CONDITIONS IS
EXPECTED BY LATE THIS WEEK.
NEAR TERM /UNTIL 7 AM TUESDAY MORNING/
ANY RESIDUAL SHOWER ACTIVITY SOUTH OF I-64 AND EAST OF I-81 WILL
GRADUALLY COME TO AN END BEFORE SUNSET. SEVERE AND HYDRO
THREATS WILL CONTINUE TO REMAIN LOW GIVEN MARGINAL CAPE, SHEAR,
AND PWATS IN THE AREA. THIS ACTIVITY IS IN ASSOCIATION WITH A
COLD FRONTAL BOUNDARY THAT CONTINUES TO SAG SOUTH ACROSS
SOUTHWEST AND SOUTHEAST VIRGINIA. FURTHER NORTH OF I-64, DRY AIR
ADVECTION (PWATS ON THE 00Z SOUNDING THIS EVENING AT KIAD DOWN
TO 0.84" WITH MID LEVEL RH AT 17 PERCENT) HAS TAKEN HOLD WITH
DEWPOINTS FALLING INTO THE MID TO UPPER 50S AND LOW 60S. SOME
VALLEY LOCATIONS (I.E MILL GAP/MUSTOE, VA, BAYARD, WV, AND
BITTINGER, MD COULD SEE LOWS IN THE UPPER 40S AND LOW 50S).
EXPECT THIS TREND TO CONTINUE ACROSS THE ENTIRETY OF THE AREA
TONIGHT WHICH IS A MUCH NEEDED REPRIEVE FROM THE OPPRESSIVE HUMIDITY
AS OF LATE. SKIES WILL ALSO CONTINUE CLEAR FROM NORTH TO SOUTH WITH
OVERNIGHT LOWS IN THE UPPER 50S AND LOW TO MID 60S. URBAN AREAS WILL
BE A TOUCH WARMER WITH LOWS JUST UNDER 70 DEGREES. SOME VALLEY FOG
IS POSSIBLE NEAR THE ALLEGHENIES/APPALACHIANS AND DOWN ACROSS
CENTRAL VA WITH THE SHOWERS EARLIER THIS EVENING. OVERALL DRY AIR
ADVECTION SHOULD MUTE THIS THREAT FOR MOST LOCATIONS OVERNIGHT INTO
EARLY TUESDAY MORNING.
SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/
CANADIAN HIGH PRESSURE WILL DOMINATE ACROSS THE REGION THROUGH
MID WEEK. DRY AND SEASONABLE CONDITIONS PREVAIL. HIGHS WILL BE
IN THE 80S EACH DAY WITH OVERNIGHT LOWS IN THE 60S. NORTHEAST
TO EAST WINDS ON TUESDAY SHIFT TO SOUTHEAST ON WEDNESDAY AS THE
HIGH SLIDES OFFSHORE. MID-LEVEL RIDGING STARTS TO BUILD INTO
THE AREA FROM THE WEST ON WEDNESDAY, BUT WE WON'T SEE ANY
SIGNIFICANT TEMPERATURE INCREASES UNTIL LATE IN THE WEEK.
LONG TERM /THURSDAY THROUGH MONDAY/
UPPER LEVEL RIDGE OVER THE MID SOUTH WILL CREST OVER THE AREA
THURSDAY EVENING RESULTING IN HIGH HEAT. BY THE END OF THE WEEK,
SURFACE HIGH PRESSURE SHIFTS OFFSHORE ALLOWING SOUTHERLY WINDS TO
DEVELOP AND DRIVE HIGHER DEWPOINTS INTO THE AREA. EXPECT HEAT
INDICES FRI AND SAT TO BE AT OR NEAR HEAT ADVISORY CRITERIA. BY
SATURDAY, THE RIDGE PATTERN BREAKS DOWN ALLOWING THUNDERSTORM
CHANCES TO INCREASE MARKEDLY, PARTICULARLY SATURDAY. A WEAK FRONT
MAY APPROACH THE AREA SUNDAY BRINGING SOME RELIEF TO THE HEAT AND
HUMIDITY.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
VFR CONDITIONS WILL CONTINUE TO PREVAIL ACROSS THE TERMINALS THIS
EVENING AND RIGHT ON THROUGH THE MIDDLE OF THE WORKWEEK. THE COLD
FRONT OF YESTERDAY HAS SINCE SAGGED INTO SOUTHWEST VA WITH JUST A
FEW RESIDUAL SHOWERS SOUTH OF KCHO AND EAST OF KLYH. THESE SHOWERS
WILL QUICKLY COME TO AN END AFTER SUNSET. WITH LINGERING LOW LEVEL
MOISTURE NEARBY, WENT AHEAD AND ADDED A LITTLE FOG AT KCHO BETWEEN
08-12Z/4-8AM TUESDAY. VSBYS MAY DROP AS LOW AS 2 TO 4 MILES BEFORE
QUICKLY IMPROVING AFTER DAYBREAK. ELSEWHERE, FOG WILL REMAIN LIMITED
AS AMPLE DRY AIR ADVECTION OVERSPREADS THE REGION. WINDS WILL REMAIN
LIGHT OUT OF THE NORTH TONIGHT BEFORE TURNING TO THE EAST AND
NORTHEAST TUESDAY. SOUTHEASTERLY WINDS AT LESS THAN 10 KTS
RETURN WEDNESDAY AS HIGH PRESSURE TO THE NORTH SLIDES OFFSHORE.
NO SIGNIFICANT WEATHER IS EXPECTED THURSDAY OTHER THAN THE HEAT AND
HUMIDITY. TEMPORARY REDUCTIONS LOOK TO RETURN TO THE TERMINALS
DURING THE AFTERNOON AND EVENING HOURS FRIDAY INTO THE WEEKEND DUE
TO THUNDERSTORMS. THIS IS IN ASSOCIATION WITH SEVERAL PIECES OF
ENERGY AHEAD OF A WEAK FRONT THAT LOOKS TO CROSS SUNDAY INTO EARLY
NEXT WEEK.
MARINE
LIGHT NORTH TO NORTHEAST WINDS ARE EXPECTED TO CONTINUE THROUGH
TUESDAY MORNING AS HIGH PRESSURE SITS NORTH OF THE WATERS. WINDS
WILL SLOWLY CHANCE TO THE EAST TUESDAY AFTERNOON BEFORE SWITCHING TO
THE SOUTHEAST WEDNESDAY AT LESS THAN 15KTS. THERE STILL REMAINS A
BRIEF WINDOW FOR SCA CONDITIONS FOR AN 1 TO 3 HOURS DUE TO NORTHERLY
CHANNELING. HIGHEST CONDFIDENCE (ALBEIT LOW) WOULD BE OVER NORTHERN
AND MIDDLE PORTIONS OF THE BAY. A MARINE WEATHER STATEMENT MAY
BE NEEDED TO ENCOMPASS THIS THREAT AS IT EVOLVES.
SCA CONDITIONS ARE POSSIBLE THURSDAY THROUGH FRI NIGHT, PARTICULARLY
AT NIGHT DUE TO CHANNELING. SMWS MAY BE NEEDED DURING THE AFTERNOON
AND EVENING HOURS THIS WEEKEND AS THUNDERSTORM CHANCES INCREASE
ACROSS THE REGION.
TIDES/COASTAL FLOODING
BY THE MIDDLE OF THE WEEK, WATER LEVELS ARE EXPECTED TO RISE
AGAIN ON STRENGTHENING SOUTHEAST WINDS. SNAPBACK TIDE COULD PUSH
WATER LEVELS INTO MINOR FLOOD STAGE AT SOME SENSITIVE LOCATIONS
(MAINLY ANNAPOLIS) BY THE MIDDLE OF THE WEEK.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...DHOF/KRR
LONG TERM...CJL
AVIATION...DHOF/CJL/EST
MARINE...DHOF/CJL/EST
TIDES/COASTAL FLOODING...KRR
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