285
FXUS61 KLWX 051418
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1018 AM EDT THU JUN 5 2025
SYNOPSIS
AN AREA OF LOW PRESSURE DOWN ACROSS THE CAROLINAS WILL SLOWLY DRIFT
NORTH TOWARD THE SOUTHERN DELMARVA LATER TODAY BRINGING INCREASED
HUMIDITY AND CLOUD COVER TO THE REGION. MEANWHILE, A COLD FRONT WILL
SLOWLY WORK EAST FROM THE OHIO RIVER VALLEY TONIGHT INTO FRIDAY
INCREASING THE CHANCES FOR SHOWERS AND THUNDERSTORMS. MORE
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED SATURDAY
INTO SUNDAY AS THE FRONT DROPS INTO THE REGION. DAILY SHOWER
AND THUNDERSTORM CHANCES LOOK TO CONTINUE THROUGH TUESDAY WITH A
STRONGER COLD FRONT SET TO CROSS BY THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
OVERALL, MOST OF TODAY LOOKS DRY OUTSIDE OF A SCATTERED
MOUNTAIN SHOWER OR THUNDERSTORM WEST OF I-81 AND SOUTH OF I-64.
THE BIGGER THEME OF TODAY WILL BE THE UPTICK IN HUMIDITY AS WELL
AS MID AND HIGH LEVEL CLOUD COVER. THIS IS DUE LARGELY IN PART
TO AN AREA OF LOW PRESSURE WORKING NORTH FROM THE COASTAL
CAROLINAS TOWARD THE SOUTHERN DELMARVA AND AN ENCROACHING COLD
FRONT FROM THE OHIO RIVER VALLEY. MEANWHILE, HIGH PRESSURE WILL
CONTINUE TO SLIDE OFFSHORE WITH JUST ENOUGH INFLUENCE OVER THE
AREA TODAY TO KEEP MOST LOCATIONS DRY OUTSIDE OF THE POTOMAC
HIGHLANDS, ALLEGHENIES, AND CENTRAL BLUE RIDGE WHERE OROGRAPHIC
LIFTING MAY HELP TOUCH OFF A FEW SHOWERS/T- STORMS GIVEN THE
WARM/HUMID AIRMASS OVERHEAD. SHOWER AND T-STORM CHANCES WILL
REMAIN CAPPED AT 20-30 PERCENT TODAY GIVEN THE LEFTOVER
SUBSIDENCE FROM THE BUCKLING RIDGE/DEPARTING HIGH PRESSURE
SYSTEM OFFSHORE.
WITH THE ADDED MID AND HIGH LEVEL CLOUD COVER EXPECT SLIGHTLY
COOLER TEMPERATURES ESPECIALLY SOUTH OF I-66/US-50 AS LOW
PRESSURE PUSHES NORTH FROM THE CAROLINAS AND WEST OF THE
ALLEGHENIES DUE TO THE INCUMBENT FRONT FROM THE OHIO RIVER
VALLEY. HIGHS IN THESE AFOREMENTIONED LOCATIONS WILL REMAIN IN
THE UPPER 70S AND LOW 80S. ELSEWHERE, EXPECT HIGHS IN THE MID
TO UPPER 80S WITH FILTERED SUNSHINE AS ADDITIONAL HIGH CLOUDS
FUNNEL INTO THE REGION. SOME HAZE HAS ALSO BEEN OBSERVED THIS
MORNING ACROSS NORTH-CENTRAL MD AND NORTHERN VA DUE TO THE
CANADIAN WILDFIRE SMOKE. AIR QUALITY ALERTS REMAIN IN PLACE FOR
NORTH BALTIMORE AND HARFORD COUNTIES WHERE THE CONCENTRATIONS OF
OZONE AND FINE PARTICULATES REMAIN THE HIGHEST. ANY SMOKE WILL
ONCE AGAIN BE DIFFUSE AND MUTE GIVEN INCREASED SOUTH TO
SOUTHEASTERLY FLOW INTO THE REGION.
CLOUD COVER AND HUMIDITY WILL CONTINUE TO INCREASE TONIGHT AS LOW
PRESSURE PUSHES UP ALONG THE DELMARVA COAST. WITH LOW PRESSURE
NEARBY, A FEW SHOWERS CANNOT BE RULED OUT OVER SOUTHERN MD, THE
NORTHERN NECK OF VA, AND THE SOUTHERN/MIDDLE PORTION OF THE
CHESAPEAKE BAY. ANY SHOWER ACTIVITY SHOULD BE FAIRLY LIGHT WITH
PRECIPITATION CHANCES CAPPED AT 30 PERCENT. A FEW LINGERING SHOWERS
AND THUNDERSTORMS ALSO CANNOT BE RULED OUT IN LOCATIONS WEST OF I-81
GIVEN THE PROXIMITY OF THE ENCROACHING FRONT NEARBY. THE LOSS
OF DAYTIME HEATING COMBINED WITH SUBSIDENCE ON THE OUTER EDGE OF
LOW PRESSURE WILL SUBDUE THE PROGRESSION OF THIS SHOWER/STORM
ACTIVITY EAST OF THE POTOMAC HIGHLANDS/ALLEGHENIES UNTIL FRIDAY.
SOME FOG IS POSSIBLE IN THE RIVER VALLEYS AND DOWN OVER
SOUTHERN MD/NORTHERN NECK OF VA LATE TONIGHT INTO EARLY FRIDAY
MORNING GIVEN THE INCREASED MOISTURE OVER THE AREA. LOWS TONIGHT
WILL FALL BACK INTO THE LOW TO MID 60S WITH UPPER 60S IN THE
BALTIMORE/DC METRO CENTERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
BY FRIDAY, WE'LL CONTINUE TO MONITOR THE PROGRESSION OF A
SLOW-MOVING COLD FRONT MOVING TOWARDS THE REGION OUT OF THE
OH VALLEY, AS WELL AS THE BROAD EXTRATROPICAL LOW PRESSURE
SYSTEM WORKING UP ALONG THE DELMARVA COAST. OUR REGION WILL BE
PINNED BETWEEN THESE TWO SYSTEMS ON FRIDAY, WHICH BRINGS ABOUT
AN INTERESTING FORECAST. THUNDERSTORMS ARE LIKELY TO FIRE ALONG
A PRE-FRONTAL TROUGH ACROSS THE POTOMAC HIGHLANDS INTO THE
SHENANDOAH VALLEY DURING THE AFTERNOON. STORMS WILL BE RATHER
SLOW TO MOVE, AND GRADUALLY PUSH EAST THROUGH THE EVENING.
THOUGH, DON'T THINK THEY MAKE IT MUCH FURTHER EAST THAN I-81 OR
THE BLUE RIDGE, AT LEAST NOT STRONG STORMS. THIS IS DUE TO THE
PRESENCE OF SUBSIDENCE AROUND THE PERIPHERY OF THE
AFOREMENTIONED LOW TO OUR SOUTH. MAINTAINING LIKELY POPS WEST
OF THE BLUE RIDGE GIVEN THE PRE-FRONTAL TROUGH AND CHANCE POPS
FURTHER EAST GIVEN THE ADDED SUBSIDENCE FROM THE DEPARTING
COASTAL LOW. POPS TO THE EAST EVEN CAME DOWN WITH THIS OVERNIGHT
CYCLE, FURTHER REINFORCING THE TOUGH BATTLE ANY STORMS WILL
FACE AS THEY TRY TO MOVE EAST.
OUTSIDE OF THE SHOWER AND THUNDERSTORM CHANCES EXPECTED A
CONTINUATION OF INCREASED HUMIDITY AND ADDED CLOUD COVER. HIGHS
WILL PUSH INTO THE UPPER 70S AND LOW TO MID 80S WITH DEWPOINTS
IN THE MID TO UPPER 60S.
LOWS FRIDAY NIGHT WILL FALL BACK INTO THE LOW TO MID 60S WITH
UPPER 60S EXPECTED IN THE METRO AREAS.
INCREASED INSTABILITY AHEAD OF AN APPROACHING COLD FRONT WILL
FUEL SHOWERS AND THUNDERSTORMS ACROSS THE REGION SATURDAY INTO
SATURDAY EVENING. HEAVY RAINFALL, ALONG WITH GUSTY WINDS AND
HAIL POSSIBLE IN THE STRONGEST THUNDERSTORMS. HIGHS WILL BE NEAR
AVERAGE FOR EARLY JUNE.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
FOR THE MOST PART, SUNDAY AND MONDAY LOOK DRY WITH HIGH PRESSURE
BUILDING IN BEHIND THE DEPARTING COLD FRONT. WE CAN'T RULE OUT
A SHOWER OR THUNDERSTORM IN SPOTS, BUT MOST AREAS WILL BE DRY.
TEMPERATURES WILL BE CLOSE TO AVERAGE BOTH DAYS.
THE HIGH WILL LIKELY GIVE WAY TO COLD FRONT SOMETIME MONDAY NIGHT OR
THROUGHOUT THE DAY TUESDAY. INCREASED CHANCES OF SHOWERS AND
THUNDERSTORMS POSSIBLE AND COULD LINGER INTO MIDWEEK AS THE
FRONT GRADUALLY SAGS SOUTH. MAINTAINING SOME RAIN CHANCES EVEN
INTO WEDNESDAY. HIGHS WILL GENERALLY BE IN THE 80S EACH DAY
(70S IN THE MOUNTAINS).
AVIATION /14Z THURSDAY THROUGH MONDAY/
SHOWER AND THUNDERSTORM CHANCES RETURN TO MRB AND CHO LATER THIS
AFTERNOON INTO THE EVENING AS THE AREA SITS SANDWICHED BETWEEN
AN INCOMING FRONT FROM THE OHIO RIVER VALLEY AND AREA OF LOW
PRESSURE MOVING UP FROM THE COASTAL CAROLINAS. ANY SHOWER AND
THUNDERSTORM ACTIVITY WILL BE RELEGATED TO TERMINALS WEST OF
KCHO AND KMRB WITH CHANCES AT OR LESS THAN 30 PERCENT AT THIS
TIME. CONDITIONS SHOULD REMAIN VFR MOST OF THE DAY WITH SUB-VFR
CONDITIONS POSSIBLE TONIGHT INTO FRIDAY MORNING AS LOW PRESSURE
PASSES TO THE SOUTHEAST. SUB-VFR CIGS WOULD LIKELY BE RELEGATED
TO CHO, BUT EVEN THAT MAY NOT QUITE GET INTO THE LOWER CLOUDS.
AT ANY RATE, HAVE ADDED A SCT040 INTO THE TAF FOR CHO OVERNIGHT
TO ILLUSTRATE THIS POSSIBILITY.
ADDITIONAL SHOWER AND THUNDERSTORM CHANCES ARE EXPECTED FRIDAY,
LEADING TO PERIODS OF SUB-VFR ESPECIALLY WEST OF THE BLUE RIDGE.
THE SHOWER AND THUNDERSTORM CHANCES ARE IN ASSOCIATION WITH A
SLOW MOVING COLD FRONT APPROACHING FROM THE WEST ALONG WITH
DEPARTING LOW PRESSURE OFFSHORE AND A PREFRONTAL TROUGH DRAPED
OVER THE MOUNTAINS. THE HIGHEST CONFIDENCE FOR SHOWERS AND
THUNDERSTORMS LOOKS TO BE WEST OF THE CORRIDOR TERMINALS
ALTHOUGH SOME ACTIVITY COULD PUSH EAST FROM THE MOUNTAINS LATE
FRIDAY AFTERNOON AND EVENING. LOW PRESSURE OFF THE COAST MAY
PROVIDE THE CORRIDOR TERMINALS WITH ENOUGH SUBSIDENCE TO LIMIT
THUNDERSTORMS OVER THE CORRIDOR PENDING IT'S PLACEMENT AND
TRACK. VFR CONDITIONS ARE EXPECTED OTHERWISE WITH LIGHT SOUTH TO
SOUTHEAST WINDS OCCASIONALLY GUSTING UP TO 15 KNOTS.
MVFR CONDITIONS POSSIBLE WITH SHOWER AND THUNDERSTORM ACTIVITY
THROUGH THE DAY SATURDAY INTO SATURDAY EVENING. VFR CONDITIONS
RETURN SUNDAY INTO MONDAY, THOUGH THERE WILL BE DAILY CHANCES
FOR SHOWERS AND STORMS EACH AFTERNOON/EVENING, WHICH COULD
RESULT IN SOME BRIEF RESTRICTIONS. SOME PATCHY FOG COULD
PRODUCE MVFR IN VALLEYS IN THE WEST OR WHERE DOWNPOURS OCCUR
DURING THE DAY. WINDS SOUTHWEST SHIFTING NORTHWEST 5 TO 10 KNOTS
SATURDAY INTO SATURDAY NIGHT. WINDS REMAINING NORTHWEST 5 TO 10
KNOTS SUNDAY AND SUNDAY NIGHT, THEN TURN BACK OUT OF THE SOUTH
TO SOUTHEAST BY MONDAY.
MARINE
SOUTH TO SOUTHEASTERLY WINDS WILL CONTINUE TO PREVAIL ACROSS
THE WATERS TODAY AS LOW PRESSURE WORKS NORTH AND EAST FROM THE
COASTAL CAROLINAS. SOME BRIEF SOUTHERLY CHANNELING IS POSSIBLE
ESPECIALLY OVER THE OPEN WATERS ALTHOUGH CONFIDENCE APPEARS LOW
FOR ANY ADVISORIES AT THIS TIME. MOST OF THE DAY SHOULD BE DRY
ALTHOUGH AND ISOLATED SHOWER/THUNDERSTORM CANNOT BE RULED OUT
OVER THE SOUTHERN CHESAPEAKE BAY ZONES LATE TONIGHT INTO FRIDAY
MORNING. CHANCES ARE GENERALLY AROUND 20 TO 30 PERCENT FOR
THAT TO OCCUR.
AN ADDITIONAL PERIOD OF MARGINAL SOUTHERLY CHANNELING IS POSSIBLE
ALONG THE BAY LATE FRIDAY AFTERNOON AND EVENING. THIS IS IN
ASSOCIATION WITH A TIGHTENING GRADIENT BETWEEN AN INCOMING FRONT
FROM THE WEST AND THE AFOREMENTIONED AREA OF LOW PRESSURE
SLIDING ALONG THE DELMARVA COAST. A FEW THUNDERSTORMS MAY BE
POSSIBLE FRIDAY AFTERNOON AND EVENING, WHICH MAY NECESSITATE
SOME SMWS GIVEN THE WARM/HUMID AIRMASS. STORMS MAY HAVE TROUBLE
MAINTAINING THEMSELVES TOWARD THE WATERS GIVEN THE FACT THAT
THE BAY AND TIDAL POTOMAC WILL SIT ON THE PERIPHERY OF THE
PASSING COASTAL LOW PRESSURE SYSTEM YIELDING SUBSIDENCE OVER THE
REGION. ONCE AGAIN THIS WILL DEPEND ON THE TRACK AND PLACEMENT
OF THE LOW LATE TONIGHT INTO FRIDAY.
ANY MARINE HAZARDS SATURDAY INTO SATURDAY NIGHT COULD BE SPECIAL
MARINE WARNINGS FROM STRONG THUNDERSTORMS IN THE AFTERNOON AND
EVENING. THIS FRONT MAY LINGER THROUGH AT LEAST MONDAY ACROSS
THE REGION, LEADING TO CONTINUED CHANCES FOR SHOWERS AND STORMS
SUNDAY AND MONDAY AFTERNOON/EVENING. OTHERWISE, NO OTHER MARINE
HAZARDS SATURDAY THROUGH SUNDAY NIGHT. WINDS SOUTHWEST BECOMING
NORTHWEST 5 TO 10 KNOTS SATURDAY AND SATURDAY NIGHT. WINDS
NORTHWEST 5 TO 10 KNOTS SUNDAY AND SUNDAY NIGHT. WINDS THEN TURN
OUT OF THE SOUTH TO SOUTHEAST ON MONDAY AS THE FRONT LIFTS BACK
THROUGH THE REGION. COULD SEE SOME NEAR-SCA GUSTS DURING THE
EVENING HOURS.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...CJL
LONG TERM...KLW
AVIATION...KLW/CJL/EST
MARINE...KLW/CJL/EST
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