352
FXUS61 KLWX 261347
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
947 AM EDT THU JUN 26 2025
SYNOPSIS
A RIDGE OF HIGH PRESSURE OVERHEAD WILL MAINTAIN HOT CONDITIONS
THROUGH THIS EVENING. DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL INCREASE THROUGH THE END OF THE WEEK. A WEAK
FRONTAL BOUNDARY WILL SLOWLY DRIFT SOUTHWARD IN TIME BEFORE
STALLING NEARBY THROUGH FRIDAY. THIS SYSTEM GRADUALLY LIFTS
NORTHWARD AWAY FROM THE AREA THIS WEEKEND. A STRONGER COLD
FRONT MAY CROSS THE REGION BY EARLY NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
CURRENT OBSERVATIONS ACROSS THE REGION SHOW A COOLER START TO
THE DAY TODAY. THIS IS LIKELY, AT LEAST PARTIALLY, DUE TO THE
CONVECTION YESTERDAY REALLY WORKING OVER THE ATMOSPHERE.
TEMPERATURES THIS MORNING ARE RUNNING A FEW DEGREES COOLER, AND
DEW POINTS ARE ALSO A COUPLE DEGREES COOLER THAN THIS TIME
YESTERDAY. MOSTLY SUNNY SKIES BEING OBSERVED FOR NOW, BUT EXPECT
THAT TO CHANGE QUICKLY BY MID-LATE MORNING. THE 12Z IAD RAOB
SHOWS A SIGNIFICANTLY MORE MOIST COLUMN THIS MORNING, WITH PWATS
ALREADY EXCEEDING TWO INCHES. A WEAK CAP IS IN PLACE, WITH CIN
VALUES AROUND 100 J/KG IN THE MIXED LAYER, BUT EXPECT THAT TO
QUICKLY MIX OUT AS WE WARM INTO THE LOW 90S BY AROUND NOON. A
ROBUST CU FIELD WILL LIKELY DEVELOP AS A RESULT, WITH CONVECTIVE
INITIATION STRICTLY FROM THE DIURNAL HEATING AND OROGRAPHIC
INFLUENCES HAPPENING PERHAPS AROUND NOON OR SHORTLY THEREAFTER.
THIS WOULD BE MOST LIKELY FOR AREAS FURTHER WEST TO START, WITH
AREAS FURTHER EAST INITIATING AN HOUR OR TWO LATER ALONG ANY
REMNANT OUTFLOW BOUNDARIES AND/OR BAY/RIVER BREEZES.
ADDITIONALLY, A STALLED SURFACE BOUNDARY ACROSS NORTHERN
PENNSYLVANIA/OHIO IS EXPECTED TO SAG SOUTHWARD IN TIME TODAY,
EVENTUALLY PUSHING INTO OUR AREA LATER THIS EVENING. AS THIS
OCCURS, ENHANCED FRONTAL LIFT COUPLED WITH PERTURBATIONS IN THE
MID/UPPER ATMOSPHERE WILL FAVOR AN INCREASING RISK OF SHOWERS
AND THUNDERSTORMS. WITH AFTERNOON HIGH TEMPERATURES RISING INTO
THE LOW/MID 90S AND CONTINUED HUMID CONDITIONS, INSTABILITY
PROFILES REMAIN QUITE ROBUST. FORECAST SURFACE-BASED CAPE VALUES
RISE INTO THE 2,500 TO 3,500 J/KG RANGE, BUT WITH RATHER WEAK
DEEP-LAYER SHEAR (AVERAGING AROUND 10 KNOTS). THIS LACK OF
VERTICAL SHEAR SUGGESTS DISORGANIZED CONVECTION WHILE FOCUSING
MORE INTENTLY ON MESOSCALE BOUNDARIES (I.E., RIVER AND BAY
BREEZES, AS WELL AS OLD CONVECTIVE OUTFLOWS/COLD POOLS).
COMPARED TO YESTERDAY, THERE ARE A FEW NOTABLE DIFFERENCES THAT
SUGGEST THAT THE HIGH-END WIND GUST POTENTIAL SHOULD BE LOWER
TODAY. SURFACE TO MIN THETA-E VALUES ARE SUBSTANTIALLY LOWER
TODAY THAN THIS TIME YESTERDAY, AND FAVOR A MORE ISOLATED
DAMAGING WIND THREAT. SECONDLY, AS PREVIOUSLY MENTIONED, THERE
IS A LOT MORE MOISTURE IN THE COLUMN TODAY, THUS WE HAVE A LOT
LESS DCAPE TO WORK WITH (ALBEIT STILL CONDUCIVE TO SOME SEVERE
GUSTS). LASTLY, MID-LEVEL LAPSE RATES ARE A BIT WEAKER THAN
YESTERDAY AS WELL. SO, IN SHORT, THINKING STORMS MAY HAVE A
SLIGHTLY HARDER TIME GETTING WELL ESTABLISHED AND EXTREMELY
TALL LIKE WE SAW YESTERDAY. HOWEVER, DO THINK THERE WILL BE A
FEW THAT ARE ABLE TO OVERCOME THESE ISSUES AND WE WILL PROBABLY
SEE AT LEAST A FEW DAMAGING WIND GUSTS. ADDITIONALLY, WITH WET
GROUND FROM STORMS YESTERDAY AND AGAIN TODAY, IT MAY NOT TAKE
SEVERE WINDS TO BLOW DOWN TREES, SO WOULD EXPECT TO SEE A GOOD
BIT OF THAT TODAY AS WELL. LASTLY ON THE THUNDERSTORM THREAT,
STORMS TODAY WILL AGAIN BE PROLIFIC LIGHTNING PRODUCERS GIVEN
THE LEVEL OF INSTABILITY.
AS WAS MENTIONED EARLIER, WITH PRECIPITABLE WATER VALUES AROUND
2 INCHES, SLOW CELL MOTIONS, AND THE POTENTIAL OF REPEAT
CONVECTION FIRING ALONG ERRATIC OUTFLOWS, FLASH FLOODING IS
POSSIBLE THIS AFTERNOON/EVENING. THE WEATHER PREDICTION CENTER
HAS PAINTED A SLIGHT RISK FOR FLASH FLOODING ACROSS AREAS EAST
OF THE CATOCTINS AND BLUE RIDGE. THE OVERNIGHT HREF ACTUALLY HAS
SOME HIGHLIGHTS ALONG THE I-95 CORRIDOR FOR POTENTIAL OF 3"+ OF
RAINFALL IN 3 HOURS. THIS IS RATHER CONCERNING, SO A FLOOD WATCH
IS BEING CONSIDERED AT THIS TIME FOR THIS AREA. ONCE 12Z
GUIDANCE COMES IN, A FINAL DECISION CAN BE MADE ON THAT A LITTLE
LATER THIS MORNING PRIOR TO CI.
MOST HIGH-RESOLUTION MODELS DEPICT ACTIVITY WANING AFTER
MIDNIGHT SO ANY SEVERE/FLOOD THREAT SHOULD WANE AT THAT POINT.
BESIDES THE CONVECTIVE THREATS, CONTINUED ABOVE AVERAGE
TEMPERATURES AND HIGH HUMIDITY LEVELS WILL CARRY HEAT INDICES
INTO THE 102 TO 107 DEGREE RANGE. FURTHERMORE, HEAT ADVISORIES
EXTEND OVER A BULK OF THE AREA OUTSIDE THE MOUNTAINS FROM 11 AM
UNTIL 7 PM THIS EVENING. CONTINUE TO FIND WAYS TO STAY COOL IN
THE HEAT BY TAKING PLENTY OF BREAKS FROM THE OUTDOORS, STAYING
HYDRATED, AND WEARING LIGHT CLOTHING. HEADING INTO THE OVERNIGHT
HOURS, THE INFLUENCE OF RAIN-COOLED AIR SHOULD HELP CARRY LOWS
INTO THE UPPER 60S TO LOW 70S (LOW/MID 60S IN THE MOUNTAINS).
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
WHILE THE PLACEMENT OF THE FRONTAL ZONE IS UNCERTAIN AND LIKELY
RE-POSITIONED BY CONVECTIVE-SCALE PROCESSES, THIS SYSTEM SHOULD
BE IN THE VICINITY OF THE MID-ATLANTIC REGION ON FRIDAY. NOT
ONLY WILL THIS CARRY AN ADDITIONAL RISK FOR SHOWERS AND
THUNDERSTORMS, BUT ALSO COMES WITH A CHALLENGING TEMPERATURE
FORECAST. FOR THOSE IN THE COOL SECTOR TO THE NORTH, HIGHS IN
THE MID/UPPER 70S ARE LIKELY. OFF TO THE SOUTH, THE WARM/MOIST
SECTOR WILL SUPPORT TEMPERATURES WELL INTO THE 80S TO NEAR 90
DEGREES. THE CURRENT FORECAST CALLS FOR THIS SEPARATION OF AIR
MASSES TO BE BETWEEN I-70 AND I-66.
THERE SHOULD BE A PARTICULAR FOCUS FOR CONVECTION IN THE
VICINITY OF THIS FRONTAL ZONE WHERE LIFT WILL BE AUGMENTED.
ALONG AND SOUTH OF THIS FRONT WILL YIELD A SEVERE WEATHER
COMPONENT TO THE STORMS WHERE INSTABILITY IS MAXIMIZED.
ADDITIONALLY, WELL ABOVE AVERAGE COLUMNAL MOISTURE PROFILES
FAVOR FURTHER INSTANCES OF FLOODING POTENTIAL. IT IS DIFFICULT
TO SAY WHERE THIS WILL OCCUR, BUT THE USUAL FOCUSES WOULD BE IN
THE URBAN CORRIDORS AND REGIONS HIT BY PREVIOUS DAYS OF HEAVY
RAINFALL. DEPENDING ON HOW QUICKLY INSTABILITY IS EXHAUSTED,
SOME OF THE CONVECTION COULD FESTER INTO THE OVERNIGHT HOURS ON
FRIDAY.
WITH MID/UPPER HEIGHT CHANGES BEING SOMEWHAT NEUTRAL, IT
REMAINS TO BE SEEN HOW MUCH NORTHWARD PROGRESS THIS BOUNDARY
MAKES ON SATURDAY. THIS SYSTEM COULD EASILY LINGER RIGHT NEAR
THE MASON-DIXON LINE WHICH WOULD MAINTAIN A MORE UNSETTLED
PATTERN DURING THE FIRST HALF OF THE WEEKEND. THE EXPECTATION IS
FOR THIS BOUNDARY TO DRIFT NORTHWARD IN TIME ON SATURDAY WHICH
WILL HELP USHER HIGHS BACK INTO THE UPPER 80S TO LOW 90S.
FURTHER, CONVECTION WOULD BE DRIVEN MORE HEAVILY BY INSTABILITY
VERSUS ALONG ANY PARTICULAR FRONTAL BOUNDARIES. BUT AS
MENTIONED, THERE IS PLENTY OF UNCERTAINTY IN HOW THIS ALL PLAYS
OUT. WILL SEE SATURDAY NIGHT'S LOWS BE A TAD MILDER THAN
PREVIOUS NIGHTS WITH READINGS IN THE UPPER 60S TO MID 70S.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
THE SUMMERTIME CONVECTION THREAT CONTINUES EACH DAY SUNDAY
THROUGH TUESDAY, MAINLY IN THE AFTERNOON AND EVENING HOURS WHEN
IT IS THE WARMEST. HIGH TEMPERATURES WILL REACH THE LOWER TO
MIDDLE 90S EACH AFTERNOON. A STRONG UPPER TROUGH AND ASSOCIATED
SURFACE COLD FRONT IS EXPECTED TO CROSS THE AREA ON TUESDAY.
THIS COULD LEAD TO AN ACTIVE AFTERNOON AND EVENING WITH MULTIPLE
ROUNDS OF CONVECTION AND/OR SEVERE THUNDERSTORMS. HIGH PRESSURE
BUILDS IN THE WAKE BY THE MIDDLE OF NEXT WEEK WHICH FAVORS A
RETURN TO DRIER WEATHER.
AVIATION /13Z THURSDAY THROUGH MONDAY/
WITH CONVECTION IN THE FORECAST THROUGH THE REMAINDER OF THE
WORK WEEK AND INTO THE FIRST HALF OF THE WEEKEND, PERIODS OF
RESTRICTIONS ARE LOOKING LIKELY AT TIMES. OTHERWISE, VFR
CONDITIONS SHOULD BE COMMONPLACE OUTSIDE OF THESE CONVECTIVE
EPISODES. FOR THIS AFTERNOON/EVENING, REMAIN CONFIDENT ENOUGH IN
THUNDERSTORM DEVELOPMENT TO HAVE A 3 TO 4 HOUR PERIOD OF TSRA
RESTRICTIONS ROUGHLY BETWEEN 20-00Z. AS SOME OF THIS MAY LINGER
AFTER DARK, HAVE MAINTAINED THE PROB30 GROUPS INTO SUBSEQUENT
HOURS AS INHERITED BY PREVIOUS SHIFTS.
AS A FRONTAL ZONE DRIFTS SOUTHWARD ACROSS THE AREA, WINDS TURN
MORE EASTERLY IN NATURE ON FRIDAY. EVENTUALLY THIS BOUNDARY DOES
RETURN NORTHWARD AS A WARM FRONT WHICH WOULD BRING A RETURN TO
SOUTH-SOUTHWESTERLIES AT SOME POINT ON SATURDAY. AND AS
MENTIONED, RESTRICTIONS ARE POSSIBLE GIVEN A DECENT CHANCE FOR
THUNDERSTORMS EACH AFTERNOON/EVENING.
VFR CONDITIONS AT ALL TERMINALS SUNDAY THROUGH MONDAY NIGHT. AT
TIMES OF CONVECTION, WE COULD SEE BRIEF MVFR VISIBILITY AND/OR
CEILINGS. WINDS WILL BE LIGHT AND VARIABLE, EXCEPT HIGHER GUSTS
IN STRONG THUNDERSTORMS.
MARINE
WHILE GRADIENTS REMAIN WEAK ENOUGH TO KEEP THE WATERWAYS FREE OF
SMALL CRAFT ADVISORIES, THE THREAT OF CONVECTION WILL MAKE FOR
HAZARDOUS BOATING CONDITIONS AT TIMES THROUGH AT LEAST SATURDAY.
IT IS DIFFICULT TO SAY WHICH DAY WILL BE THE MOST ACTIVE IN
TERMS OF THUNDERSTORM DEVELOPMENT, BUT THE DEGREE OF CONTINUED
HEAT AND HUMIDITY SHOULD MAINTAIN A DAILY 30-60 PERCENT CHANCE
OF STORMS EACH AFTERNOON/EVENING. AS USUAL, FREQUENT LIGHTNING
IS POSSIBLE IN ANY SUCH STORM, WITH THE STRONGER CELLS LIKELY
REQUIRING SPECIAL MARINE WARNINGS.
NO MARINE HAZARDS SUNDAY THROUGH MONDAY NIGHT. IF THUNDERSTORMS
MOVE OUT OVER THE WATERS, THEN SPECIAL MARINE WARNINGS MAY BE
WARRANTED. WINDS LIGHT AND VARIABLE THROUGH THE PERIOD, EXCEPT
HIGHER GUSTS IN STRONG THUNDERSTORMS.
TIDES/COASTAL FLOODING
TIDAL ANOMALIES WILL REMAIN SLIGHTLY ELEVATED THROUGH THE NEXT
SEVERAL HIGH TIDE CYCLES. THIS WILL KEEP WATER LEVELS SLIGHTLY
ELEVATED FOR THE MORE SENSITIVE TIDAL SITES. AT THIS POINT, ONLY
ANNAPOLIS IS SLATED TO REACH ACTION STAGE DURING THE NEXT
COUPLE OF ASTRONOMICAL HIGH TIDES.
CLIMATE
HERE ARE SOME DAILY HIGH TEMPERATURE RECORDS ON JUNE 26, 2025:
A '+' SIGN INDICATES MULTIPLE YEARS CURRENTLY HOLD THAT RECORD.
***THURSDAY, JUNE 26TH, 2025***
LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR)
WASHINGTON-NATIONAL (DCA) 101F (1952) 77F (1952)+
WASHINGTON-DULLES (IAD) 99F (2024) 72F (2023)+
BALTIMORE (BWI) 99F (2024)+ 80F (1952)
BALTIMORE INNER HARBOR (DMH) 104F (1998) 83F (1952)
MARTINSBURG (MRB) 102F (1943) 75F (1949)
CHARLOTTESVILLE (CHO) 99F (1998) 78F (1952)
ANNAPOLIS (NAK) 98F (1998)+ 81F (1952)
HAGERSTOWN (HGR) 98F (1954)+ 75F (1952)
LWX WATCHES/WARNINGS/ADVISORIES
DC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR DCZ001.
MD...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR MDZ003>006-008-
011-013-014-016>018-502>508.
VA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR VAZ026>031-
036>040-050-051-053>057-501-502-505-506-526-527.
WV...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR WVZ050>053-055-
502-504.
MARINE...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ530.
SYNOPSIS...BRO
NEAR TERM...CJL/BRO
SHORT TERM...BRO
LONG TERM...BRO/KLW
AVIATION...BRO/KLW
MARINE...BRO/KLW
TIDES/COASTAL FLOODING...LWX
CLIMATE...LWX
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page