291
FXUS61 KLWX 090128
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
928 PM EDT TUE JUL 8 2025
SYNOPSIS
A FRONT WILL SAG ACROSS THE REGION OVERNIGHT AND STALL FOR
SEVERAL DAYS AND INTO THE WEEKEND. DISTURBANCES WILL MOVE ALONG
THE FRONT AND BRING A THREAT FOR MORE SHOWERS AND THUNDERSTORMS
EACH DAY AND INTO THE EVENING HOURS.
NEAR TERM /THROUGH WEDNESDAY/
NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS ARE MOVING EAST
ACROSS EASTERN VIRGINIA, THE LOWER POTOMAC, SOUTHERN MARYLAND,
AND CENTRAL CHESAPEAKE BAY. THESE ARE THE ZONES THAT STILL HAVE
2000 TO 3000 J/KG MLCAPE. OVER THE NEXT FEW HOURS, THE
CONVECTION WILL WANE AS IT MOVES OUR OVER THE DELMARVA.
OTHERWISE, PATCHY FOG COULD FORM ACROSS THE WESTERN HALF OF OUR
REGION OVERNIGHT, WHILE SOME LOW STRATUS CLOUDS DEVELOP IN THE
EAST AS THE CONVECTION FADES. LOW TEMPERATURES WILL DROP INTO
THE UPPER 60S OVER THE MOUNTAINS AND INTO THE MIDDLE 70S ALONG
AND EAST OF I-81.
THROUGH THE DAY ON WEDNESDAY, A STRONGER MID-LEVEL TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE REGION. STRONGER CONVERGENCE WILL
PROVIDE MORE WIDESPREAD CONVECTION THROUGH THE MIDDLE AND LATTER
PART OF THE AFTERNOON AND CONTINUING INTO THE EVENING. MOST OF
THE PROLONGED AND HEAVIER ACTIVITY WILL BE FOCUSED ALONG AND
EAST OF THE BLUE RIDGE. HENCE, WITH THIS IN MIND, A FLOOD WATCH
FOR THE POTENTIAL FOR FLASH FLOODING HAS BEEN RE-ISSUED. IT GOES
INTO EFFECT FROM 2PM WEDNESDAY THROUGH MIDNIGHT THURSDAY.
SHOWERS AND STRONG TO SEVERE THUNDERSTORMS THAT DEVELOP FROM
MID-AFTERNOON ON WILL HAVE THE POTENTIAL TO PRODUCE TORRENTIAL
DOWNPOURS, DAMAGING WINDS, LIGHTNING, AND HAIL. A TORNADO CAN'T
BE RULED OUT EITHER GIVEN THE STRONG MID-LEVEL TROUGH, A JET
STREAK MOVING BY TO THE NORTH, RICH HUMIDITY, AND STRONG
CONVERGENCE. RAINFALL RATES COULD REACH 2 INCHES PER HOUR IN
AREAS WHERE THE FLOOD WATCH IS IN EFFECT. WINDS COULD GUST OVER
60 MPH TOO.
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/
WHILE THERE IS EXPECTED TO BE SOME STRONG TO SEVERE
THUNDERSTORMS THROUGH MID-EVENING IN THE CENTRAL AND EASTERN
ZONES ON WEDNESDAY, MUCH OF THE CONVECTION WILL ONCE AGAIN WANE
LATER IN THE EVENING AND OVERNIGHT. HIGHS WILL BE NEAR OR
SLIGHTLY ABOVE AVERAGE IN THE UPPER 80S TO LOWER 90S.
THIS SCENARIO OF STRONG CONVECTION IN THE AFTERNOON AND EARLY
EVENING, THEN WANING, IS EXPECTED TO REPEAT ITSELF ON THURSDAY
INTO THURSDAY EVENING. THE STATIONARY FRONT DOESN'T APPEAR TO
HAVE A SHOVE IN ANY ONE DIRECTION OUT OF OUR REGION. HIGHS
SHOULD REACH THE UPPER 80S FOR THE MOST PART ON THURSDAY.
LONG TERM /FRIDAY THROUGH TUESDAY/
NOT MUCH CHANGE IN THE EXTENDED PATTERN AS THERE IS NO REAL
PROGRESSIVE STORM SYSTEM TO CLEAN US OUT OF THIS WARM, MUGGY, AND
STORMY PATTERN. TEMPERATURES WILL TREND SLIGHTLY COOLER FOR THE END
OF THE WORKWEEK AND INTO THE WEEKEND GIVEN ADDED CLOUD COVER WITH
THE STALLED FRONT NEARBY. PIECES OF SHORTWAVE ENERGY WILL CONTINUE
TO RIDE ALONG THE STALLED BOUNDARY AS IT BISECTS THE AREA. CURRENT
12Z SYNOPTIC GUIDANCE SHOWS THE FRONT STALLING SOMEWHERE IN THE
VICINITY OF SOUTHWEST PA, CENTRAL MD, AND NORTHERN VA DURING THE
SATURDAY AND SUNDAY TIMEFRAME. WITH THE FRONT NEARBY EXPECT
CONTINUED CHANCES FOR SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON
AND EVENING HOURS. AS FOR SEVERE WEATHER, UNCERTAINTY REMAINS GIVEN
THE PLACEMENT OF THE FRONT AND TIMING OF SHORTWAVE ENERGY AS IT
PIVOTS ACROSS. CURRENT CSU LEARNING MACHINE GUIDANCE, CIPS PATTERN
RECOGNITIONS, AND LONG RANGE NSSL PROBS ARE LEANING TOWARD THE
SATURDAY AND SUNDAY TIMEFRAME AS THE NEXT POTENTIAL PERIOD FOR
ORGANIZED CONVECTION. EITHER WAY THUNDERSTORMS WILL HAVE THE
POTENTIAL OF PRODUCING LOCALLY DAMAGING WINDS AND INSTANCES OF FLASH
FLOODING EACH AFTERNOON. THIS IS DUE LARGELY IN PART TO THE STAGNANT
WARM AND MOIST AIRMASS HANGING TOUGH OVER THE REGION. TEMPERATURES
FRIDAY THROUGH THE WEEKEND WILL RANGE FROM THE MID TO UPPER 80S AND
LOW 90S. HEAT INDICES WILL MAKE IT FEEL MORE LIKE THE MID TO UPPER
90S.
BEYOND SUNDAY, UNCERTAINTY CONTINUES IN REGARDS TO A POTENTIAL
FRONTAL PASSAGE. 12Z SYNOPTIC/ENSEMBLE GUIDANCE SHOW A COLD
FRONT EJECTING OUT OF THE MIDWEST AND OHIO RIVER VALLEY SOME
TIME MONDAY INTO TUESDAY NEXT WEEK. THIS FRONT DOES NOT APPEAR
TO ARRIVE UNTIL MID NEXT WEEK LEADING TO A CONTINUATION OF DAILY
SHOWER AND THUNDERSTORM CHANCES UNTIL IT PASSES THROUGH.
TEMPERATURES AND PRECIPITATION WILL CONTINUE TO REMAIN ABOVE
AVERAGE WITHIN THE BACK HALF OF THE LONG TERM PERIOD.
AVIATION /01Z WEDNESDAY THROUGH SUNDAY/
A SHOWER OR TWO COULD MOVE ACROSS MTN, BWI OR CHO OVER THE NEXT
2 HOURS OR SO, BUT TERMINALS LOOK DRY FOR THE MOST PART
THROUGHOUT THE NIGHT. VFR CONDITIONS MOST LIKELY. SHOULD SOME
MIST OR PATCHY FOG DEVELOP OVERNIGHT, CHO WOULD BE MORE LIKELY
TO ENCOUNTER WITH A MINOR DROP IN VISIBILITY.
AS FOR THE DAY WEDNESDAY INTO WEDNESDAY EVENING, ANOTHER ROUND
OF SHOWERS AND STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP
ALONG A STALLED FRONT WITH A MODERATELY STRONG MID-LEVEL TROUGH
MOVING ALONG IT. THE RAPID DEVELOPMENT AND MOVEMENT OF STRONG TO
POSSIBLY SEVERE THUNDERSTORMS ACROSS THE TERMINALS COULD DROP
VISIBILITY AND CEILINGS INTO THE MVFR CATEGORY BRIEFLY, BEFORE
VFR CONDITIONS RETURN LATER IN THE EVENING AND OVERNIGHT. THE
DEVELOPMENT AND INTENSITY OF SUCH CONVECTION COULD LEAD TO
FLOODING NEAR OR AT THE TERMINAL AS WELL. OTHERWISE, DAMAGING
WINDS AND HAIL MAY OCCUR AS WELL. THROUGH THE LATTER HALF OF
WEDNESDAY NIGHT, PATCHY FOG COULD FORM AT THE TERMINALS.
MARINE
ADDITIONAL SHOWERS AND THUNDERSTORMS ARE POSSIBLE WEDNESDAY
AFTERNOON AND EVENING THAT COULD PROMPT MORE SPECIAL MARINE
WARNINGS.
SUB-SCA LEVEL WINDS ARE EXPECTED THURSDAY THROUGH THE UPCOMING
WEEKEND DESPITE A STALLED FRONT NEARBY. GRADIENTS WILL REMAIN FAIRLY
WEAK WITH VARIABLE WIND DIRECTIONS DICTATED BY THE PLACEMENT OF THE
FRONT. ONCE AGAIN SMWS WILL BE NEEDED AT TIMES DURING THE AFTERNOON
AND EVENING HOURS ON THURSDAY GIVEN DAILY CONVECTIVE DEVELOPMENT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING
FOR DCZ001.
MD...FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING
FOR MDZ004>006-008-011-013-014-016>018-503>508.
VA...FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING
FOR VAZ036>040-050-051-053>057-501-502-505-506-526-527.
WV...NONE.
MARINE...FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING
FOR ANZ530.
SYNOPSIS...LFR
NEAR TERM...LFR/KLW
SHORT TERM...LFR
LONG TERM...EST
AVIATION...LFR/KLW/EST
MARINE...LFR/KLW/EST
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