942
FXUS61 KLWX 270112
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
912 PM EDT TUE MAY 26 2026
WHAT HAS CHANGED
NO MAJOR CHANGES WERE MADE TO THE FORECAST THIS EVENING.
KEY MESSAGES
- 1) LOCALIZED FLOOD THREAT TODAY, WITH FLOOD AND SEVERE
THUNDERSTORM THREATS AREAWIDE WEDNESDAY.
- 2) HIGH PRESSURE MOVES INTO THE REGION FRIDAY, WITH
TEMPERATURES REMAINING SEASONABLE INTO NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...LOCALIZED FLOOD THREAT TODAY, WITH FLOOD AND SEVERE
THUNDERSTORM THREATS AREAWIDE WEDNESDAY.
CURRENT SURFACE ANALYSIS AS OF 9 PM SHOWS A VERY DIFFUSE FRONTAL
BOUNDARY DRAPED ACROSS THE FORECAST AREA FROM NORTHWEST TO
SOUTHEAST, WITH LOWER 70S DEWPOINTS TO THE SOUTH AND WEST OF THE
BOUNDARY, AND MID TO UPPER 60S DEWPOINTS FURTHER NORTHEAST. ONLY
A FEW WIDELY SCATTERED SHOWERS AND SPRINKLES ARE ONGOING ACROSS
THE FORECAST AREA AT THE MOMENT, WITH MORE WIDESPREAD SHOWERS
AND A FEW STORMS ONGOING ACROSS SOUTHERN VIRGINIA. THIS AREA
WITH HIGHER COVERAGE OF SHOWERS IS EXPECTED TO LIFT NORTHWARD
OVERNIGHT AS A WEAK PUSH OF WARM ADVECTION ENSUES ALOFT. WHILE A
STRAY SHOWER OR TWO CAN'T BE RULED OUT AT ANY POINT DURING THE
NIGHT, THE AFOREMENTIONED MORE FOCUSED AREA OF SHOWERS WILL LIFT
NORTHWARD INTO CENTRAL VIRGINIA OVER THE NEXT FEW HOURS, AND
WILL EVENTUALLY IMPACT LOCATIONS FURTHER NORTH DURING THE SECOND
HALF OF THE NIGHT. A FEW ELEVATED THUNDERSTORMS MAY ALSO
DEVELOP, POTENTIALLY PRODUCING SOME ISOLATED HEAVIER DOWNPOURS.
COME LATER TONIGHT, MODELS SUPPORT A GREATER COVERAGE OF STORMS
ALONG THE FRONT ARCING INTO OUR NW ALLEGHENY ZONES. HAVE ISSUED
A FLOOD WATCH IN COORDINATION WITH PBZ/RLX/CTP. THE LOCAL
STREAMS/CREEKS ARE RUNNING RATHER HIGH UP THERE, AND AN
ADDITIONAL 1-3" OF RAIN COULD PUT THE STREAMS/CREEKS AT
BANKFULL.
BY WED THE UPPER TROUGHING TO THE NORTH BEGINS TO SLIDE SOUTH,
WITH AN ACCOMPANYING COLD FRONT ALSO PUSHING SOUTH THROUGH THE
MID- ATLANTIC. THE PRESENCE OF GROWING INSTABILITY, LINGERING
DEEP LAYER MOISTURE, AND MUCH MORE FORCING/SHEAR FROM THE UPPER
TROUGH IS GOING TO INTRODUCE A SEVERE WEATHER THREAT FOR MOST OF
THE AREA. SPC HAS ADDED A SLIGHT RISK (LEVEL 2 OUT OF 5) FOR
SOUTH OF THE POTOMAC RIVER INCLUDING DC AND SOUTHERN MD.
ELSEWHERE, A MARGINAL RISK REMAINS IN EFFECT. COVERAGE OF
THUNDERSTORMS IS STILL UNCERTAIN, BUT IT WILL CERTAINLY BE MORE
THAN TODAY. 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.
IN TERMS OF SEVERE THUNDERSTORM HAZARDS, DAMAGING WINDS LOOK TO
BE THE PRIMARY THREAT. HODOGRAPHS ARE LONG AND STRAIGHT. LACK OF
HODOGRAPH CURVATURE SUGGESTS THAT TORNADOES LIKELY WON'T BE A
THREAT. THERMODYNAMIC PROFILES ARE VERY SATURATED IN THE
VERTICAL, WHICH SUGGESTS THAT LARGE HAIL LIKELY WON'T POSE MUCH
OF A THREAT EITHER. LOW-LEVEL LAPSE RATES AREN'T OVERLY STEEP
(AROUND 7C/KM), AND WITH THE DEEP NEAR-SATURATION THROUGH THE
COLUMN, DCAPE IS ALSO LOW. BOTH OF THESE FACTORS COULD WORK
AGAINST STORMS PRODUCING STRONG DOWNBURST WINDS. HOWEVER, PWATS
ARE HIGH (AT JUST UNDER 2 INCHES), SO WATER LOADED DOWNBURSTS
CAN'T BE RULED OUT. THERE'S AMPLE SHEAR IN THE VERTICAL, AND
MANY CAMS ACTUALLY SHOW A PRIMARILY CELLULAR MODE (SOME OF WHICH
PRESUMABLY COULD BE SUPERCELLS WITH EFFECTIVE BULK SHEAR VALUES
BETWEEN 30 AND 40 KNOTS). HOW EFFICIENT THESE CELLS ARE AT
PRODUCING DAMAGING WINDS TOMORROW REMAINS ONE OF THE MAIN
FORECAST QUESTIONS.
KEY MESSAGE 2...HIGH PRESSURE MOVES INTO THE REGION FRIDAY,
WITH TEMPERATURES REMAINING SEASONABLE INTO NEXT WEEK.
SKIES TREND CLEARER BEGINNING THU AND GOING INTO FRI AS A SFC
HIGH TRANSITIONS INTO THE REGION, ALONG WITH SIGNIFICANT DRY
AIR COMING IN FROM THE NORTH. DESPITE AN ULL SWINGING DOWN INTO
THE NORTHEAST THAT COULD BRING A VERY SLIGHT CHANCE FOR SHOWERS
TO FORM HERE ALONG THE SOUTHERN EDGE OF THE REGION, PERSISTENT
HIGH PRESSURE OFF TO THE WEST WILL QUICKLY TRANSITION THE LOW
OFFSHORE AND MINIMIZE PRECIP CHANCES IN THE AREA. THIS PATTERN
SIGNAL HAS STAYED CONSISTENT OVER SEVERAL MODEL RUNS NOW, BUT
IT'S STILL WORTH NOTING THAT ANY SOUTHWARD SHIFT IN TRACK FROM
THIS LOW WOULD INCREASE ANY CHANCE FOR SHOWERS OVER THE WEEKEND.
FOR NOW, IT LOOKS LIKE ONLY A SLIGHT UPTICK IN CLOUD COVER WILL
RESULT FROM THIS WHILE THE STEMMING COLD FRONT KEEPS TEMPS
MODERATE THROUGH THE END OF THE FORECAST PERIOD. HIGHS
CONSISTENTLY RANGE IN THE 70S FOR MOST AREAS THROUGH MON, WITH
LOWS GENERALLY RANGING IN THE 50S OVERNIGHT BETWEEN FRI AND MON.
CONDITIONS REMAIN CLEAR GOING INTO NEXT WEEK ON MON, WITH
UPPER-LEVEL RIDGING PERSISTING.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
CONDITIONS ARE VFR AT MOST TERMINALS THIS EVENING, BUT CIGS
DROP AGAIN TONIGHT TO IFR TO LIFR LEVELS. RESTRICTIONS PERSIST
INTO WED. AFTERNOON TO EVENING THUNDERSTORMS ARE LIKELY TO MOVE
ACROSS THE AREA, AND THIS COULD LEAD TO BRIEF REDUCTIONS AND
GUSTY WINDS AT ALL TERMINALS. A COLD FRONT SWEEPS THROUGH WED
NIGHT, WITH DRY AND VFR CONDITIONS RETURNING FOR THU.
VFR CONDITIONS ARE EXPECTED FRI AND SAT. LIGHT NW WINDS COULD
TEMPORARILY FLOW W BETWEEN FRI AND SAT BEFORE RETURNING TO NW
FLOW.
MARINE
LIGHT AND VARIABLE WINDS ARE EXPECTED OVER THE WATERS TONIGHT
INTO WED. THUNDERSTORMS ARE POSSIBLE ACROSS THE WATERS WED
AFTERNOON, AND SMWS MAY BE NEEDED. SCA CONDITIONS ARE POSSIBLE
THU INTO THU NIGHT.
WIND GUSTS PREDOMINANTLY STAY BELOW SCA CRITERIA FRI, BUT COULD
BRIEFLY APPROACH LOW-END SCA CRITERIA IN THE SOUTHERN PORTIONS
OF THE CHESAPEAKE BAY IN THE MORNING. WINDS START TO INCREASE
OVER THE WATERS LATE SAT AFTERNOON AND EVENING, WITH SCAS
BECOMING A POSSIBILITY OVER THE SOUTHERN BAY DURING THEN.
NW WINDS BRIEFLY TREND S'LY ON FRI NIGHT BEFORE FLOWING
N'LY AGAIN BY SAT EVENING.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...FLOOD WATCH FROM 4 AM EDT WEDNESDAY THROUGH WEDNESDAY
AFTERNOON FOR MDZ501-509-510.
VA...NONE.
WV...FLOOD WATCH FROM 4 AM EDT WEDNESDAY THROUGH WEDNESDAY
AFTERNOON FOR WVZ501-503-505.
MARINE...NONE.
DISCUSSION...KJP/CPB/KRR
AVIATION...KJP/CPB/KRR
MARINE...KJP/CPB/KRR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page