175
FXUS61 KLWX 170126
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
926 PM EDT WED JUL 16 2025
SYNOPSIS
A COLD FRONT WILL MOVE IN FROM THE NORTH THURSDAY NIGHT. THIS
FRONT WILL STALL OUT ON FRIDAY AND THEN OSCILLATE BACK AND
FORTH ACROSS THE AREA THROUGH EARLY NEXT WEEK.
NEAR TERM /UNTIL 6 AM THURSDAY MORNING/
BROKEN CLUSTER OF THUNDERSTORMS STRETCHES FROM NORTH CENTRAL
MARYLAND TO NORTH CENTRAL VIRGINIA AT 9 PM, SPREADING EASTWARD.
DEEP LAYER SHEAR OF 25-35 KT AHEAD OF AN MCV (HIGHER THAN
ORIGINALLY PROGGED) IS RESULTING IN SOME ORGANIZATION AND A FEW
SUPERCELLS. WHILE A LOCALIZED SEVERE WEATHER THREAT MAY PERSIST
FOR A BIT LONGER, THE PRIMARY THREATS REMAIN VERY HEAVY RAIN
AND FREQUENT LIGHTNING. WHILE LESS INTENSE, A FEW SHOWERS AND
STORMS ARE DEVELOPING TO THE SOUTHWEST, INDICATIVE OF A TRAILING
BOUNDARY. IN ADDITION, WE ARE WATCHING STORMS OVER WEST
VIRGINIA, WHICH RECENT GUIDANCE HAS HOLDING TOGETHER INTO AT
LEAST WESTERN PORTIONS OF THE AREA INTO THE OVERNIGHT.
QUESTIONABLE HOW FAR EASTWARD THIS ACTIVITY MAKES IT GIVEN
LIKELY CONVECTIVE OVERTURNING. HOWEVER, AN INCREASING LOW LEVEL
JET IN THE ANOMALOUSLY MOIST AIRMASS COULD SUPPORT A
CONTINUATION OF AT LEAST SOME CONVECTION. WOULD THINK THIS WOULD
BE WEAKER OVERALL, BUT WILL CONTINUE TO MONITOR. WITH PLENTY OF
LINGERING CLOUD COVER, FOG DEVELOPMENT MAY BE MORE LIMITED BUT
CERTAINLY POSSIBLE IF THERE ARE BREAKS LOWS WILL BE IN THE UPPER
60S TO MID 70S.
SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/
LOW PRESSURE WILL TRACK THROUGH THE ST. LAWRENCE VALLEY TOMORROW
AS A TRAILING COLD FRONT DROPS SOUTHWARD THROUGH THE EASTERN
GREAT LAKES. FLOW ALOFT WILL STAY ZONAL, WITH SLIGHT MID-LEVEL
HEIGHT RISES. A HOT AND HUMID AIRMASS WILL REMAIN IN PLACE AT
THE SURFACE, BUT SOME DRIER AIR WILL START TO BUILD IN ALOFT,
DROPPING PRECIPITABLE WATER VALUES BACK BELOW TWO INCHES. THE
HOT AND HUMID CONDITIONS AT THE SURFACE WILL PUSH US CLOSE TO
HEAT ADVISORY CRITERIA, AS TEMPERATURES CLIMB INTO THE LOW-MID
90S AND DEWPOINTS HOLD IN THE 70S. A HEAT ADVISORY HAS BEEN
ISSUED ALONG AND EAST OF THE FALL LINE WHERE HIGHER DEW POINTS
MAY POOL, BUT LATER ADDITIONS MAY BE NECESSARY. THE DRIER AIR
ALOFT AND LACK OF LARGE SCALE FORCING SHOULD LEAD TO A MUCH
LOWER COVERAGE OF STORMS TOMORROW, BUT A FEW STORMS ARE STILL
EXPECTED TO FORM ON A PREFRONTAL TROUGH DURING THE AFTERNOON AND
MOVE EASTWARD ACROSS THE AREA. THE DRIER AIR AND INCREASING
FLOW ALOFT SHOULD ALSO LIMIT THE POTENTIAL FOR FLASH FLOODING.
DAMAGING WINDS MAY POTENTIALLY BECOME A GREATER THREAT, AS MODEL
SOUNDINGS SHOW MUCH HIGHER DCAPE VALUES (AROUND 1000-1500 J/KG)
AND STEEPER LOW- LEVEL LAPSE RATES (CLOSER TO 8-9 C), BOTH OF
WHICH SHOULD ENABLE STORMS TO HAVE STRONGER COLD POOL DRIVEN
DOWNDRAFTS. WE'RE CURRENTLY OUTLOOKED IN A MARGINAL RISK FOR
SEVERE THUNDERSTORMS BY SPC, DRIVEN BY DAMAGING WIND POTENTIAL.
ANY THUNDERSTORMS SHOULD QUICKLY WIND DOWN AND PROGRESS OFF TO
OUR EAST DURING THE EVENING HOURS, LEADING TO DRY CONDITIONS
OVERNIGHT.
THE SYSTEM'S COLD FRONT WILL MOVE SOUTHWARD ACROSS THE AREA LATE
THURSDAY NIGHT, BEFORE EVENTUALLY STALLING OUT ACROSS THE AREA
ON FRIDAY. CENTRAL VIRGINIA TO SOUTHERN MARYLAND WILL LIKELY
REMAIN ON THE WARM/HUMID SIDE OF THE BOUNDARY, AND WILL HAVE A
MUCH GREATER CHANCE FOR AFTERNOON SHOWERS/THUNDERSTORMS THAN
LOCATIONS FURTHER NORTH DURING THE DAY FRIDAY. HIGH TEMPERATURES
WILL RANGE FROM THE MID 80S ACROSS NORTHERN MD TO THE LOW 90S IN
CENTRAL VA AND SOUTHERN MD. DEWPOINTS WILL RANGE FROM THE MID
60S ACROSS NORTHERN MD TO MID 70S ACROSS CENTRAL VA.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
A WARM FRONT WILL LIFT NORTH OF THE AREA SATURDAY WHILE HEIGHTS
ALOFT FALL IN ADVANCE OF A COLD FRONT FCST TO SWEEP THROUGH THE AREA
SUNDAY NIGHT. EXPECT ACTIVE THUNDERSTORM DAYS BOTH SAT AND SUN WITH
RISK OF SOME SEVERE WX AND ISOLATED FLASH FLOODING.
AFTER MONDAY, GLOBAL MODELS SHOW SUBTROPICAL RIDGE BUILDING OVER THE
MID-ATLANTIC LEADING TO A HOTTER TREND AND A SIGNIFICANT DOWNWARD
TREND IN CONVECTION.
AVIATION /01Z THURSDAY THROUGH MONDAY/
THUNDERSTORMS WITH GUSTY WINDS, FREQUENT LIGHTNING, AND HEAVY
RAIN ARE MOVING ACROSS THE METRO TERMINALS THIS EVENING. SHOWERS
MAY LINGER FOR A TIME AFTER THE HEAVY RAIN PASSES BUT ALREADY
SEEING DRYING MOVING IN FROM THE WEST. QUESTIONABLE WHETHER
ACTIVITY SW OF STAUNTON HOLDS TOGETHER INTO CHO. ALSO WATCHING
THUNDERSTORMS IN CENTRAL/NORTHERN WEST VIRGINIA, WHICH SOME
MODELS HOLD TOGETHER INTO THE AREA OVERNIGHT. AT THIS POINT,
ONLY INCLUDED A PROB30 AT MRB AS THEY MAY FALL APART WITH
EASTWARD MOVEMENT OVERNIGHT. WITH LINGERING CLOUD COVER, BELIEVE
THE THREAT OF FOG IS MORE LIMITED TONIGHT, THOUGH COULD DEVELOP
IF CLEARING OCCURS.
WINDS WILL PICK UP OUT OF THE WEST TO SOUTHWEST THURSDAY, AND
MAY GUST TO AROUND 20 KNOTS AT TIMES. PREVAILING VFR CONDITIONS
ARE EXPECTED, BUT A BRIEF THUNDERSTORM CAN'T BE RULED OUT DURING
THE AFTERNOON OR EVENING HOURS. AREAL COVERAGE OF THE STORMS
SHOULD BE MUCH LOWER THAN TODAY, SO HAVE JUST INCLUDED A PROB30
GROUP FOR NOW. ADDITIONAL THUNDERSTORMS APPEAR POSSIBLE ON
FRIDAY, ESPECIALLY IN THE VICINITY OF CHO.
ACTIVE THUNDERSTORM DAYS BOTH SAT AND SUNDAY WITH RISK OF SOME
SEVERE.
MARINE
WINDS ARE PICKING UP OUT OF THE SOUTH THIS EVENING, WITH SCA
CONDITIONS SPREADING SOUTH TO NORTH OVERNIGHT. SMWS HAVE ALSO
BEEN ISSUED AS GUSTY THUNDERSTORMS ARE MOVING ACROSS THE WATERS
THIS EVENING. WINDS WILL TURN OUT OF THE WEST TO SOUTHWEST
TOMORROW. LOW-END SCA CONDITIONS APPEAR POSSIBLE DURING THE
DAYTIME HOURS WITHIN WSW FLOW, SO THE ADVISORY WAS EXPANDED AND
EXTENDED. ADDITIONAL THUNDERSTORMS MAY FORM TOMORROW AFTERNOON,
AND POTENTIALLY COULD LEAD TO THE ISSUANCE OF SMWS LATE
TOMORROW AFTERNOON OR TOMORROW EVENING, BUT COVERAGE LOOKS TO BE
MUCH LOWER. SUB- SCA LEVEL NORTHWESTERLY WINDS ARE EXPECTED
OVER THE WATERS ON FRIDAY.
SCA CONDITIONS POSSIBLE SAT NIGHT INTO MONDAY EVENING WITH SCT-NMRS
THUNDERSTORMS.
TIDES/COASTAL FLOODING
SOUTHERLY WINDS WILL LEAD TO ELEVATED TIDAL ANOMALIES THROUGH
THE END OF THE WEEK. ANNAPOLIS IS FORECAST TO REACH ACTION
STAGE DURING HIGH TIDE THROUGH TOMORROW MORNING. HOWEVER,
OUTSIDE OF FRESHWATER INFLUENCES FROM HEAVY RAINFALL, THE THREAT
FOR TIDAL FLOODING APPEARS LOW.
LWX WATCHES/WARNINGS/ADVISORIES
DC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR DCZ001.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR DCZ001.
MD...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MDZ003>006-008-011-
013-014-501>510.
SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EDT THURSDAY FOR
MDZ008.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR MDZ008-011-
013-014-016>018-508.
VA...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ025>031-036>040-
051-053-054-501>508-526-527.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR VAZ053>055-
057-527.
WV...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ050>053-055-
501>506.
MARINE...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR ANZ530.
SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EDT THURSDAY FOR
ANZ530-535-536-538-539-542.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR ANZ530.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ531-532-
540.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ533-534-
537-541-543.
SYNOPSIS...AVS
NEAR TERM...ADS
SHORT TERM...AVS
LONG TERM...KLW
AVIATION...ADS/AVS/KLW
MARINE...ADS/AVS/KLW
TIDES/COASTAL FLOODING...LWX
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