974
FXUS61 KLWX 061807
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
207 PM EDT MON JUL 6 2026
WHAT HAS CHANGED
SHOWERS AND THUNDERSTORMS HAVE BEGUN TO DEVELOP AS OF EARLY
AFTERNOON. CONTINUED DEVELOPMENT IS ANTICIPATED INTO THIS
EVENING, BEFORE GRADUALLY WANING OVERNIGHT.
KEY MESSAGES
- 1) A RISK OF A FEW SEVERE THUNDERSTORMS AND SPOTTY FLASH
FLOODING CONTINUES THROUGH TUESDAY.
- 2) DAILY SHOWER AND THUNDERSTORM CHANCES CONTINUE AS A COLD
FRONT BRINGS PRECIPITATION AND THE RETURN OF SEASONABLE
TEMPERATURES.
DISCUSSION
KEY MESSAGE 1...A RISK OF A FEW SEVERE THUNDERSTORMS AND SPOTTY
FLASH FLOODING CONTINUES THROUGH TUESDAY.
A FRONT WAS ENHANCING CONVERGENCE NEAR THE TERRAIN, ACROSS
NORTH-CENTRAL VA INTO SOUTHERN MD. SCATTERED TO NUMEROUS
THUNDERSTORMS WERE DEVELOPING IN THIS CORRIDOR AS OF MID
AFTERNOON. TEMPERATURES ARE SLOWLY RISING THROUGH THE 80S WITH
DEW POINTS HOLDING IN THE LOW TO MID 70S.
THE FRONT WILL MEANDER ABOUT THE REGION THE NEXT 24 TO 36
HOURS, OFTEN BEING SHIFTED AROUND BY CONVECTIVE-SCALE PROCESSES.
THE PATTERN ALOFT FEATURES A VERY BROAD POSITIVELY-TILTED
TROUGH STRETCHING FROM THE UPPER GREAT LAKES DOWN TOWARD THE
OZARKS. AS THIS TROUGH EDGES EASTWARD, A SERIES OF IMPULSES WILL
CONTINUE TO RIDE OVER THE MENTIONED SURFACE BOUNDARY. THERE IS
SOME HINT OF THIS UPPER TROUGH WEAKENING, BUT ITS REMNANTS WOULD
SLOWLY MIGRATE EASTWARD TO THE ATLANTIC COAST DURING THE NEXT
COUPLE DAYS. ALL IN ALL, THIS WILL LEND ITSELF TOWARD ADDITIONAL
ACTIVE WEATHER DAYS OVER THE MID-ATLANTIC REGION.
THERE IS A THREAT FOR BOTH ISOLATED SEVERE THUNDERSTORMS AS
WELL AS INSTANCES OF FLASH FLOODING THROUGH THIS EVENING. THE
OVERALL THERMODYNAMIC PROFILE HAS GRADUALLY SHIFTED OVER TOWARD
MORE OF A HEAVY RAIN SIGNATURE VERSUS WIDESPREAD SEVERE STORMS.
INSTABILITY COMES DOWN WITH A TALL/SKINNY CAPE PROFILE WITH HIGH
FREEZING LEVELS/DEEP WCLS WHICH IS SUPPORTIVE OF VERY
HEAVY/WARM RAIN PROCESSES. THE TROPICAL NATURE OF THE AIR MASS
WILL CARRY PRECIPITABLE WATER VALUES INTO THE 2 TO 2.25 INCH
RANGE. FORECAST SOUNDINGS SHOW LIGHT LOW-LEVEL EASTERLIES WHICH
OCCURS BENEATH WEAK WESTERLIES. THIS WILL FAVOR SOME VERY SLOW
CELL MOTIONS AND THUS A RISK FOR FLASH FLOODING. THERE IS
CONCERN FOR STORMS TO STALL OR "LOCK ON" TO TERRAIN OR MESOSCALE
BOUNDARIES LIKE OUTFLOW AND BAY OR RIVER BREEZES, FURTHER
INCREASING POTENTIAL FOR HEAVY RAINFALL.
THE CONVECTIVE EVOLUTION LOOKS VERY MESSY OVERALL AND RATHER
UNCERTAIN IN ANY ONE LOCATION. GENERALLY SPEAKING, ALL SIGNS
POINT TOWARD DESTABILIZATION OF THE BOUNDARY LAYER AND RESULTANT
CONVECTIVE INITIATION OVER THE HIGHER TERRAIN AND ALONG THE
STALLED FRONT. GIVEN MINIMAL CAPPING, OTHER MESOSCALE FEATURES
LIKE THE LEE-SIDE TROUGH AND RIVER/BAY BREEZES WILL ALSO BE
SITES FOR CONVECTIVE INITIATION. BASED ON OUTPUT FROM THE
LATEST HIGH-RESOLUTION SUITE AS WELL AS MESOANALYSIS, EVOLUTION
OF THE CONVECTION WILL BE RATHER CHAOTIC. THIS WOULD INCLUDE
ACTIVITY SPAWNING OFF COLLIDING OUTFLOWS, REPEAT ACTIVITY, AND
POSSIBLE TRAINING IN A WEST-EAST FASHION GIVEN UNIDIRECTIONAL
ZONAL FLOW. FLOOD WATCHES ARE IN EFFECT FOR MUCH OF THE REGION
UNTIL MIDNIGHT TONIGHT.
WHERE THIS FRONTAL ZONE LIES ON TUESDAY WILL DICTATE THE LEVEL
OF THREAT FOR ADDITIONAL ACTIVE WEATHER. THE FORECAST SUGGESTS
THIS BOUNDARY SHOULD LIE ALONG I-66/US-50 DURING THE MORNING
HOURS BEFORE SAGGING SOUTHWARD TO THE VIRGINIA/NORTH CAROLINA
BORDER BY THE NIGHT. THUS, THERE IS SOME RISK FOR ADDITIONAL
CONVECTION WHICH INCLUDES A FEW SEVERE STORMS AND FURTHER FLASH
FLOODING. MARGINAL RISK AREAS ARE BEING ADVERTISED FOR BOTH THE
SEVERE AND FLOOD THREATS WITH THIS SYSTEM. MAINLY OVERCAST SKIES
AND NORTHEASTERLY ONSHORE WINDS SHOULD HOLD TEMPERATURES BELOW
AVERAGE INTO TUESDAY. FORECAST HIGHS WILL BE IN THE UPPER 70S TO
MID 80S, WITH UPPER 60S TO 70S FOR MOUNTAIN LOCALES.
KEY MESSAGE 2...DAILY SHOWER AND THUNDERSTORM CHANCES CONTINUE AS A
COLD FRONT BRINGS PRECIPITATION AND THE RETURN OF SEASONABLE
TEMPERATURES.
AN APPROACHING COLD FRONT BRINGS SHOWERS AND THUNDERSTORMS TO THE
FORECAST AREA THURSDAY INTO FRIDAY. HOT AND HUMID CONDITIONS
WILL LEAD TO MODERATE INSTABILITY. THIS ALONG WITH MODEST SHEAR
MAY RESULT IN AT LEAST ISOLATED SEVERE POTENTIAL. WITH PLENTY
OF MOISTURE IN THE ATMOSPHERE, HEAVY RAINFALL WILL ALSO BE
POSSIBLE. THE COLD FRONT SLOWLY PUSHES ACROSS THE FORECAST AREA
FRIDAY NIGHT AND INTO SATURDAY WITH SEASONABLE TEMPERATURES
EXPECTED IN ITS WAKE. HIGH TEMPERATURES FOR THE WEEKEND WILL BE
IN THE UPPER 70S TO 80S WITH OVERNIGHT LOW TEMPERATES DROPPING
INTO THE 60S TO LOW 70S.
HEADING INTO EARLY NEXT WEEK, THERE ARE SIGNS AT A POTENTIALLY
AMPLIFIED PATTERN WHICH COULD BRING A RETURN TO STORM CHANCES.
AVIATION /18Z MONDAY THROUGH SATURDAY/
WEAK GRADIENTS WILL MAINTAIN LIGHT WINDS WHICH WILL BECOME
VARIABLE AT TIMES, THOUGH MAINLY OUT OF THE EAST TO NORTHEAST.
THE MAIN CONVECTIVE WINDOW IS BETWEEN 21Z-03Z THIS EVENING WHERE
RESTRICTIONS ARE LIKELY AT TIMES, THOUGH 18Z OBS INDICATE
INITIATION MAY BE IMMINENT NEAR DCA (WITHIN THE NEXT 1-2 HOURS).
SOME CONVECTION MAY LINGER A BIT LONGER BEFORE SHIFTING TOWARD
ANOTHER NIGHT OF LOW STRATUS (LIKELY IFR).
FOR TUESDAY, THE MAIN FRONTAL ZONE SLOWLY BEGINS TO PULL SOUTH
OF I-66/US-50. HOWEVER, ITS CLOSE PROXIMITY WILL KEEP SHOWERS
AND THUNDERSTORMS IN THE PICTURE AGAIN. ADDITIONAL STORM-DRIVEN
RESTRICTIONS ARE POSSIBLE IN THIS ENVIRONMENT. EXPECT MAINLY
NORTHEASTERLY WINDS OVER THE AREA AS THIS BOUNDARY CONTINUES
PUSHING SOUTHWARD.
SOUTHWEST WINDS ON THURSDAY BLOW 5 TO 10 KNOTS ACROSS THE TERMINALS.
SHOWERS AND THUNDERSTORMS MAY RESULT IN FLIGHT RESTRICTIONS WITH
REDUCED CEILINGS AND VISIBILITIES. WINDS SHIFT TO WESTERLY ON
FRIDAY, GUSTING UP TO 15 KNOTS IN THE AFTERNOON. SHOWERS AND
THUNDERSTORMS CONTINUE TO BE POSSIBLE FRIDAY AFTERNOON. WINDS SHIFT
TO NORTHWEST IN THE WAKE OF A FRONTAL PASSAGE SATURDAY, GUSTING
AROUND 15 KNOTS IN THE AFTERNOON.
MARINE
WEAK SUMMERTIME GRADIENTS WILL LARGELY KEEP THE MARINE ZONES
FREE OF SMALL CRAFT ADVISORIES. HOWEVER, ADDITIONAL DAYS OF
ACTIVE CONVECTION SHOULD LEAD TO A GREATER THREAT OF SPECIAL
MARINE WARNINGS. BESIDES THE GUSTY THUNDERSTORM WINDS, OTHER
HAZARDS WOULD INCLUDE FREQUENT LIGHTNING AND VERY HEAVY RAIN.
THE MOST ACTIVE PERIOD IS LIKELY THROUGH TUESDAY GIVEN A FRONTAL
ZONE NEARBY. AS THIS BOUNDARY SAGS SOUTHWARD TO THE CAROLINAS,
DAILY CONVECTION BECOMES LESS WIDESPREAD FOR WEDNESDAY.
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS LEAD TO A RISK FOR SMWS
THURSDAY AND FRIDAY. SOUTHWEST WINDS ON THURSDAY SHIFT TO WESTERLY
ON FRIDAY, REMAINING MAINLY BELOW SCA CRITERIA EACH DAY. ON
SATURDAY, WINDS SHIFT TO NORTHWESTERLY IN THE WAKE OF A FRONTAL
PASSAGE.
TIDES/COASTAL FLOODING
LIGHT ONSHORE (EAST TO NORTHEAST FLOW) THE NEXT COUPLE DAYS
FOLLOWED BY SOUTHERLY FLOW WILL CAUSE RISING TIDES LATER THIS
WEEK. THIS MAY RESULT IN NEAR MINOR FLOODING OF VULNERABLE
SHORELINE THE SECOND HALF OF THIS WEEK.
LWX WATCHES/WARNINGS/ADVISORIES
DC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR DCZ001.
MD...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MDZ003>006-008-011-
013-014-016>018-503>508.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MDZ501-502-510.
VA...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ027>031-037>040-
050-051-053>057-501-502-505>507-526-527.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ025-026.
WV...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ051>053.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ050-055-502>504-
506.
MARINE...NONE.
DISCUSSION...AVS/BRO/DHOF
AVIATION...AVS/BRO/DHOF
MARINE...AVS/BRO/DHOF
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