363
FXUS61 KLWX 270714
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
314 AM EDT WED MAY 27 2026
WHAT HAS CHANGED
FLOOD WATCH CONTINUES FOR WESTERN MD AND THE UPPER POTOMAC
HIGHLANDS THROUGH THIS AFTERNOON. CONTINUE TO MONITOR DEVELOPING
CONVECTION OVER OH/WV THAT WILL MOVE INTO THE AREA THIS MORNING.
KEY MESSAGES
- 1) SEVERE THUNDERSTORMS AND A FEW INSTANCES OF FLOODING ARE
POSSIBLE THIS AFTERNOON AND EVENING.
DISCUSSION
KEY MESSAGE 1...SEVERE THUNDERSTORMS AND A FEW INSTANCES OF FLOODING
ARE POSSIBLE THIS AFTERNOON AND EVENING.
THE BERMUDA HIGH REMAINS IN PLACE TODAY ACROSS THE SOUTHWEST
ATLANTIC, WITH A STREAM OF TROPICAL MOISTURE ADVECTING NORTHWARD TO
THE MID-ATLANTIC ON THE RIDGE'S WESTERN PERIPHERY. THE 00Z IAD
SOUNDING HAD UPWARDS OF 1.9" PWAT, AND THAT MOISTURE IS EXPECTED TO
REMAIN IN PLACE TODAY. ALOFT, A STRONG UPPER TROUGH DIGS SOUTH OVER
THE EASTERN GREAT LAKES, DRAGGING WITH IT AN ASSOCIATED SURFACE COLD
FRONT. A STALLED FRONTAL BOUNDARY REMAINS IN PLACE ACROSS SOUTHERN
VA THIS MORNING, AND IS EXPECTED TO LIFT SLIGHTLY NORTH THIS
AFTERNOON. SEVERAL WAVES OF ENERGY ALOFT TRAVERSE ACROSS THE STALLED
BOUNDARY THROUGH THIS EVENING.
THIS IS GOING TO PRODUCE AT LEAST A COUPLE ROUNDS OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. THE FIRST WILL BE FROM EARLY MORNING
CONVECTION OVER OH/WV THAT REACHES THE ALLEGHENY FRONT AROUND
SUNRISE THIS MORNING. THESE SHOWERS/STORMS ARE GOING TO BE SLOW
MOVING AND COULD PRODUCE A QUICK 1-3" ACROSS PARTS OF WESTERN MD AND
THE UPPER POTOMAC HIGHLANDS. GIVEN THE SATURATED GROUND CONDITIONS
FROM DAYS OF RAIN, THIS PRODUCE INSTANCES OF FLOODING. AS SUCH, A
FLOOD WATCH REMAINS IN EFFECT FOR THESE AREAS THROUGH THIS AFTERNOON.
THE TIMING FOR THE NEXT ROUND OF THUNDERSTORMS REMAINS A BIT
UNCERTAIN. 00Z CAM GUIDANCE INDICATE STORMS DEVELOPING EARLIER, FROM
LATE MORNING TO MID AFTERNOON, THOUGH THE RRFS STILL HAS THE MAIN
THUNDERSTORM WINDOW FROM MID AFTERNOON TO EARLY EVENING.
SPC HAS MAINTAINED THE SLIGHT RISK (LEVEL 2 OUT OF 5) FOR SOUTH OF
THE POTOMAC RIVER, INCLUDING DC AND SOUTHERN MD, WITH A MARGINAL
RISK (LEVEL 1 OF 5) TO THE NORTH. STORM MOTION IS GOING TO BE
FASTER AS DEEP-LAYER WINDS INCREASE, BUT LOCALLY HEAVY RAINFALL
COULD PRODUCE SOME FLOOD THREAT, ESPECIALLY IN URBAN AREAS.
DAMAGING WIND GUSTS ARE GOING TO BE THE PRIMARY THREAT FROM ANY
SEVERE THUNDERSTORMS THAT DEVELOP TODAY. WHILE NOT EXPECTING
WIDESPREAD SEVERE STORMS, A FEW COULD PRODUCE WET MICROBURSTS IN
A NEARLY SATURATED ENVIRONMENT. LOW-LEVEL LAPSE RATES ARE
FORECAST AROUND 7-7.5 C/KM, AND EFFECTIVE DEEP SHEAR AROUND 40
KNOTS. THIS FAVORS SOME ORGANIZED MULTI-CELL CLUSTERS OR LINE
SEGMENTS THAT CROSS THE AREA FROM NORTHWEST TO SOUTHEAST.
BY LATE EVENING THE MAJORITY OF THESE THUNDERSTORMS WILL PUSH
SOUTH OF THE AREA, WITH RESIDUAL SOME SHOWERS/STORMS LINGERING
INTO THE EARLY PART OF THE NIGHT. NOT EXPECTING SEVERE WEATHER
WITH ANY LATE CONVECTION IN THE AREA.
THE FRONT MOVES SOUTH OF THE AREA BY EARLY THURSDAY MORNING, WITH
CLEARING SKIES AND MOSTLY DRY CONDITIONS BEHIND IT. A REINFORCING
FRONT MOVES THROUGH THURSDAY AFTERNOON, WHICH COULD KICK OFF A FEW
SHOWERS AND STORMS IN CENTRAL VA WHERE SOME MOISTURE LINGERS. RAIN
CHANCES ARE LOW AT AROUND 20-30PCT. AFTER THAT, DRY AND SEASONAL
CONDITIONS EXPECTED FRIDAY.
A FEW EXTRA CLOUDS MAY BE NOTED SATURDAY, ESPECIALLY NORTH OF
I-66/US-50 AND SOUTH OF I-64 AS A SERIES OF UPPER LEVEL LOW
PRESSURE SYSTEMS PASS NEARBY. THE BIGGER STORY FOR THE EXTENDED
PERIOD WILL BE THE RETURN OF SUNSHINE AND SEASONABLE/SLIGHTLY
BELOW NORMAL TEMPERATURES. EXPECT HIGHS IN THE 70S (60S
MOUNTAINS) THROUGH TUESDAY WITH OVERNIGHT LOWS IN THE 40S AND
50S. UPPER LEVEL RIDGING WILL PERSISTS THROUGH THE MIDDLE OF
NEXT WEEK WITH A GRADUAL WARMING TREND EXPECTED.
AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
LOW CLOUDS AND FOG DEVELOP THIS MORNING, PRODUCING IFR TO LIFR
CONDITIONS AT AREA TERMINALS. THESE RESTRICTIONS WILL PERSIST FOR
MUCH OF THE DAY AS MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS MOVE
ACROSS THE AREA. THE MOST LIKELY TIME FOR STRONGER THUNDERSTORMS
WILL BE DURING THE AFTERNOON TO EVENING, THOUGH TIMING REMAINS
UNCERTAIN. A COLD FRONT SWEEPS THROUGH TONIGHT, BRINGING DRY AND VFR
CONDITIONS THURSDAY AND FRIDAY.
VFR CONDITIONS ARE EXPECTED FRIDAY THROUGH EARLY NEXT WEEK.
LIGHT NORTHWEST WINDS LESS THAN 10-15 KTS.
MARINE
SHOWERS AND THUNDERSTORMS ARE FORECAST TO MOVE ACROSS THE WATERS
THIS AFTERNOON TO EVENING. SOME OF THESE STORMS WILL BE CAPABLE OF
PRODUCING STRONG WIND GUSTS, IN ADDITION TO LIGHTNING STRIKES.
SPECIAL MARINE WARNINGS WILL LIKELY BE NEEDED FOR PARTS OF THE
WATERS. A COLD FRONT SWEEPS THROUGH ON THURSDAY, AND NORTHERLY
CHANNELING BEHIND THE FRONT COULD PRODUCE SCA CONDITIONS THROUGH
THURSDAY EVENING. SUB-SCA CONDITIONS LIKELY FRIDAY.
ADDITIONAL SCAS WILL BE NEEDED SATURDAY AFTERNOON AND EVENING
DUE TO NORTHERLY CHANNELING. SUNDAY AND MONDAY BRING NO MARINE
HAZARDS AT THIS TIME.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...FLOOD WATCH THROUGH THIS AFTERNOON FOR MDZ501-509-510.
VA...NONE.
WV...FLOOD WATCH THROUGH THIS AFTERNOON FOR WVZ501-503-505.
MARINE...NONE.
DISCUSSION...KRR/EST
AVIATION...KRR/EST
MARINE...KRR/EST
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