228
FXUS61 KLWX 170729
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
329 AM EDT WED JUN 17 2026
WHAT HAS CHANGED
AN ISOLATED SHOWER IS MOVING EAST-NORTHEAST ACROSS EASTERN
HARFORD COUNTY AND INTO WESTERN CECIL COUNTY IN MARYLAND.
ADDITIONAL LINEAR SHOWERS ARE NOTED MOVING ACROSS KING GEORGE
COUNTY IN VIRGINIA AND ACROSS THE LOWER TIDAL POTOMAC. A THIRD
BATCH OF SHOWERS WITH EMBEDDED THUNDER WILL BE MOVING ACROSS
NORTHWESTERN GARRETT COUNTY IN MARYLAND WITHIN THE NEXT HOUR OR
TWO.
KEY MESSAGES
- 1) HEAT, HUMIDITY, AND AN APPROACHING COLD FRONT BRING THE
NEXT CHANCE FOR SEVERE WEATHER ON THURSDAY.
- 2) A WARM FRONT IS SPAWNING A COUPLE OF SHOWERS IN PARTS OF
NORTHEAST MARYLAND AND FAR SOUTHERN MARYLAND. A THUNDERSTORM
CANNOT BE RULED OUT IN PARTS OF THE REGION.
- 3) THUNDERSTORM POTENTIAL WILL RETURN LATE SUNDAY INTO
MONDAY.
DISCUSSION
KEY MESSAGE 1...HEAT, HUMIDITY, AND AN APPROACHING COLD FRONT
BRING THE NEXT CHANCE FOR SEVERE WEATHER ON THURSDAY.
A VERY STRONG LOW PRESSURE SYSTEM IS FORECAST TO TRACK NORTHEAST
FROM THE GREAT LAKES ON THURSDAY WITH THE ASSOCIATED COLD FRONT
PUSHING ACROSS THE FORECAST AREA THROUGH THE DAY. AHEAD OF THE
COLD FRONT, SOUTHERLY FLOW USHERS IN WARM AIR WITH HIGH
TEMPERATURES IN THE 80S TO MID 90S. GUSTY WINDS SHOULD KEEP
HEAT INDICES NEAR THE HIGH TEMPERATURE, ALTHOUGH HOT AND HUMID
CONDITIONS ARE EXPECTED.
THE COMBINATION OF THE WARM AND HUMID AIR SURGE AHEAD OF THE
COLD FRONT AND INCREASING WINDS WILL RESULT IN THE POSSIBILITY
OF STRONG TO SEVERE THUNDERSTORMS THURSDAY INTO THURSDAY
EVENING. THE STORMS PREDICTION CENTER HAS ALL OF OUR FORECAST
REGION IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR THURSDAY
AND THURSDAY NIGHT, EXCEPT FOR NORTHERN GARRETT, NORTHERN
ALLEGANY, AND WESTERN WASHINGTON COUNTIES IN MARYLAND. THE MAIN
THREAT WITH THESE POSSIBLE SEVERE THUNDERSTORMS WILL BE
DAMAGING WINDS GIVEN THE WIND FIELD. MOST RECENT GUIDANCE IS
INDICATING THAT THE BEST FORCING WILL BE NORTH OF THE FORECAST
AREA, THEREFORE LEADING TO LOWER CONFIDENCE IN THE SEVERE
THREAT. IF STORMS DEVELOP, THERE IS A HIGH CEILING FOR IMPACTS
ALTHOUGH WESTERLY DOWNSLOPING FLOW OVER THE FORECAST ARE
COMBINED WITH LACK OF FORCING MAY INHIBIT CONVECTION FROM
DEVELOPING. WE WILL CONTINUE TO MONITOR AS THURSDAY GETS CLOSER.
THE WEATHER PREDICTION CENTER HAS GARRETT COUNTY IN MARYLAND IN
A SLIGHT RISK FOR EXCESSIVE RAINFALL THURSDAY INTO THURSDAY
EVENING. THIS INDICATES THAT HEAVY RAINFALL, ACCOMPANYING
FREQUENT SHOWERS AND STRONG THUNDERSTORMS, COULD LEAD TO
ISOLATED FLOODING IN PLACES.
IN THE WAKE OF THE COLD FRONT, TEMPERATURES WILL BE ABOUT 10 TO
15 DEGREES COOLER COMPARED TO THE DAY BEFORE. PRECIPITATION
LINGERS INTO FRIDAY MORNING, ALTHOUGH SURFACE HIGH PRESSURE
BUILDING OVERHEAD YIELDS DRY CONDITIONS AND DECREASING CLOUD
COVER THROUGH THE DAY.
KEY MESSAGE 2...A WARM FRONT IS SPAWNING A COUPLE OF SHOWERS IN
PARTS OF NORTHEAST MARYLAND AND FAR SOUTHERN MARYLAND. A
THUNDERSTORM CANNOT BE RULED OUT IN PARTS OF THE REGION.
A WARM FRONT, CURRENTLY WIGGLING NORTHWARD ACROSS EAST-CENTRAL
VIRGINIA AND SOUTHERN MARYLAND, IS SPAWNING ISOLATED TO
SCATTERED SHOWERS DURING THE EARLY MORNING HOURS THIS MORNING. A
RUMBLE OF THUNDER CANNOT BE RULED OUT OVER THE NEXT 1 TO 3
HOURS. AREAS OFF TO THE WEST SHOULD STAY DRY. ADDITIONAL SHOWERS
ARE MOVING ACROSS SOUTHWEST PENNSYLVANIA AND WILL CLIP
NORTHWESTERN GARRETT COUNTY IN MARYLAND OVER THE NEXT HOUR OR
TWO.
KEY MESSAGE 3...THUNDERSTORM POTENTIAL WILL RETURN LATE SUNDAY INTO
MONDAY.
BROAD LOW PRESSURE REMAINS IN THE REGION SATURDAY. A SECOND COLD
FRONT MAY SLIDE THROUGH THE AREA, BUT DRY WEATHER IS LIKELY.
TEMPERATURES WILL BE SEASONABLE, BUT THE NOTICEABLE CHANGE WILL
BE THE DRIER, LESS HUMID AIRMASS ALONG WITH BREEZY NORTHWEST
WINDS.
MODEL SPREAD INCREASES CONSIDERABLY FOR SUNDAY INTO EARLY NEXT WEEK
AS THE NEXT SHORTWAVE TROUGH EMANATES FROM A CLOSED LOW OVER CENTRAL
CANADA. THIS WILL LEAD TO LOW PRESSURE DEVELOPING BETWEEN THE OHIO
VALLEY AND EAST COAST, POTENTIALLY STRENGTHENING OFF THE COAST EARLY
NEXT WEEK. BASED ON THE CURRENT SPREAD IN TIMING, PRECIPITATION
CHANCES COULD INCREASE AS EARLY AS SUNDAY, BUT THERE IS MORE MODEL
AGREEMENT FOR MONDAY. WHILE THUNDERSTORMS ARE POSSIBLE, INSTABILITY
MAY BE LIMITED, ESPECIALLY DEPENDING ON THE NORTHERLY ADVANCE OF THE
WARM SECTOR. OVERALL IT WILL BE LESS HOT AND HUMID COMPARED TO SOME
OF THE RECENT EVENTS, SO ANY THREAT FOR STRONG TO SEVERE STORMS WILL
BE MORE CONDITIONAL. THE LARGEST SPREAD IN TEMPERATURES IS MONDAY,
DEPENDENT ON THE POSITION OF THE FRONTS.
AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. MOST OF ANY
SHOWERS OVER THE NEXT 1 TO 3 HOURS WILL LIFT AND MOVE NORTHEAST
OF THE BWI AND MTN TERMINALS. NO SIGNIFICANT REDUCTIONS IN
CEILINGS OR VISIBLITIES ARE EXPECTED. WINDS WILL TURN MORE
SOUTHWESTERLY THROUGHOUT TODAY.
PRIMARILY VFR CONDITIONS ARE EXPECTED ON THURSDAY. BACKGROUND
WINDS WILL BE OUT OF THE SOUTHWEST ON THURSDAY, AND COULD GUST
IN EXCESS OF 30 KNOTS AT TIMES. TEMPORARY DROPS TO SUB-VFR
CONDITIONS AND EVEN STRONGER WINDS MAY BE POSSIBLE IN
THUNDERSTORMS THURSDAY AFTERNOON.
VFR CONDITIONS ARE LIKELY SATURDAY BUT NORTHWESTERLY WINDS MAY GUST
TO AROUND 25 KT. THE NEXT FRONTAL SYSTEM MAY APPROACH SUNDAY BUT IS
MORE LIKELY TO BRING SHOWERS AND THUNDERSTORMS MONDAY.
MARINE
A FEW SHOWERS WILL MOVE ACROSS PARTS OF THE FAR NORTHERN ZONES
OF THE CHESAPEAKE BAY AND THE ZONES ADJACENT TO FAR SOUTHERN
MARYLAND AS A WARM FRONT LIFTS NORTHWARD. WINDS SHIFT TO
SOUTHWEST TODAY WHICH MAY SUPPORT SMALL CRAFT ADVISORIES FOR
PORTIONS OF THE WATERS. SCAS APPEAR LIKELY ON THURSDAY IN
SOUTHWESTERLY FLOW. GALE FORCE WINDS ARE POSSIBLE THURSDAY
AFTERNOON OVER THE NORTHERN TIDAL POTOMAC AND NORTHERN PORTIONS
OF THE CHESAPEAKE BAY. SMWS WILL ALSO LIKELY BE NEEDED AS
THUNDERSTORMS MOVE OVER THE WATERS ON THURSDAY AS STRONG TO
SEVERE THUNDERSTORMS POTENTIALLY TRACK OVER THE WATERS. SMALL
CRAFT ADVISORIES ARE POSSIBLE SATURDAY IN NORTHWESTERLY FLOW.
WINDS MAY BE LIGHTER SUNDAY AS HIGH PRESSURE PASSES TO THE
SOUTH.
TIDES/COASTAL FLOODING
TIDES WILL HAVE THE POTENTIAL TO REACH MINOR FLOOD, ESPECIALLY
ANNAPOLIS TODAY. OTHER SITES WILL SHOW AND INCREASE AS WELL AS
AN INCREASING SOUTHWESTERLY FLOW EVOLVES AHEAD OF THURSDAY'S
FRONT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
DISCUSSION...ADS/AVS/KLW
AVIATION...ADS/AVS/KLW
MARINE...ADS/AVS/KLW
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