227
FXUS61 KLWX 141359
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
959 AM EDT FRI AUG 14 2026
WHAT HAS CHANGED
HAVE BEEN CLOSELY MONITORING THE TRACK OF UPSTREAM CONVECTION
TRACKING ACROSS THE CENTRAL APPALACHIANS. ADDED SOME THUNDER
MENTION ALONG THE ALLEGHENY FRONT GIVEN RESIDUAL LIGHTNING
STRIKES ACROSS CENTRAL WEST VIRGINIA.
KEY MESSAGES
- 1) SEVERE THUNDERSTORMS ARE POSSIBLE ON SUNDAY.
- 2) SEASONABLY WARM CONDITIONS AND DAILY CHANCES FOR SHOWERS
AND THUNDERSTORMS ARE EXPECTED THROUGH MONDAY, WITH DRIER
CONDITIONS FOR TUESDAY AND WEDNESDAY.
DISCUSSION
KEY MESSAGE 1...SEVERE THUNDERSTORMS ARE POSSIBLE ON SUNDAY.
A POTENT SHORTWAVE BY LATE-SUMMER STANDARDS AND AN ASSOCIATED
AREA OF LOW PRESSURE WILL TRACK ACROSS ONTARIO TOWARD HUDSON
BAY ON SUNDAY, WITH A LIKELY CONVECTIVELY INDUCED DISTURBANCE
AND ASSOCIATED WEAK AREA OF LOW PRESSURE TRACKING INTO THE GREAT
LAKES. LOW-LEVEL WINDS WILL TURN OUT OF THE SOUTH IN RESPONSE TO
THIS DISTURBANCE, DRAWING A BOUNDARY THAT IS CURRENTLY STALLED
OUT TO OUR SOUTH NORTHEASTWARD AS A WARM FRONT. THIS FRONT IS
EXPECTED TO CLEAR MUCH OF THE AREA BY SUNDAY EVENING, ADVECTING
IN A VERY WARM, HUMID, AND HIGHLY UNSTABLE AIRMASS INTO THE
REGION. HOWEVER THERE ARE SOME UNCERTAINTIES WITH REGARD TO JUST
HOW FAR NORTH AND EAST THIS HIGHLY UNSTABLE AIRMASS WILL MAKE
IT. GUIDANCE IS IN GOOD AGREEMENT THAT LOCATIONS TO THE WEST OF
THE BLUE RIDGE WILL DESTABILIZE, BUT THERE'S GREATER SPREAD IN
SOLUTIONS FURTHER EAST.
AN ATYPICALLY STRONG LOW-LEVEL JET FOR LATE SUMMER WILL
ACCOMPANY THIS SYSTEM. MODEL SOUNDINGS SHOW LARGE, CLOCKWISE
TURNING HODOGRAPHS, WITH AMPLE STREAMWISE VORTICITY AND SRH AT
LOW-LEVELS. WHEN COMBINED WITH 2000 J/KG OF MLCAPE, THIS RAISES
CONCERNS FOR SEVERE THUNDERSTORMS, WITH SUPERCELLS POSSIBLE.
DAMAGING WINDS SHOULD BE THE PRIMARY THREAT, BUT A TORNADO OR
TWO CAN'T BE RULED OUT GIVEN THE HIGH SRH ENVIRONMENT IN PLACE.
AS MENTIONED BEFORE, LOCATIONS TO THE WEST OF THE BLUE RIDGE
APPEAR TO HAVE THE GREATEST CHANCE FOR SEVERE THUNDERSTORMS, BUT
THERE IS PLENTY OF TIME FOR THINGS TO CHANGE WITH TWO DAYS OF
CONVECTION UPSTREAM OF THE EVENT.
KEY MESSAGE 2...SEASONABLY WARM CONDITIONS AND DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH MONDAY, WITH
DRIER CONDITIONS FOR TUESDAY AND WEDNESDAY.
A TYPICAL LATE SUMMERTIME PATTERN WILL REMAIN IN PLACE THROUGH
EARLY NEXT WEEK, WITH SEASONABLE TEMPERATURES AND DAILY CHANCES
FOR SHOWERS AND THUNDERSTORMS. HIGH TEMPERATURES WILL GENERALLY
BE IN THE MID 80S TO AROUND 90 EACH DAY, WITH OVERNIGHT LOWS IN
THE UPPER 60S TO LOW 70S.
AN EARLY MORNING THUNDERSTORM COMPLEX HAS BEGUN TO PUSH OUT OF
THE OHIO VALLEY TOWARD THE CENTRAL APPALACHIANS. WHILE IT HAS
UNDERGONE A GREAT DEAL OF WEAKENING IN THE LAST FEW HOURS, THIS
SYSTEM DOES HAVE A DECENT AMOUNT OF LIGHTNING WHILE CROSSING
CENTRAL WEST VIRGINIA. FURTHER, THE SWIRL ON RADAR SIGNIFIES A
REMNANT MESOSCALE CONVECTIVE VORTEX (MCV) ACCOMPANYING THIS
CLUSTER OF STORMS. BASED ON THE SURFACE BOUNDARY BEING OFF TO
THE SOUTH, THIS COMPLEX IS LARGELY ELEVATED IN NATURE. EXPECT MUCH
OF THIS ACTIVITY TO GRADUALLY DISSIPATE, BUT REMNANT MID-UPPER
LEVEL DISTURBANCES ASSOCIATED WITH THIS ACTIVITY WILL LIKELY
PROGRESS INTO THE AREA LATER TODAY, EVENTUALLY SPARKING THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. INSTABILITY IS MAINLY
EXPECTED TO BE FOCUSED ACROSS SOUTHWESTERN PORTIONS OF THE
FORECAST AREA, WITH LOCATIONS TO THE SOUTH AND WEST OF THE
POTOMAC HAVING THE GREATEST CHANCE FOR A THUNDERSTORM THIS
AFTERNOON. A PASSING SHOWER CAN'T BE RULED OUT ANYWHERE, BUT
NORTHEASTERN MARYLAND WILL HAVE THE GREATEST CHANCE TO REMAIN
DRY.
THUNDERSTORM ACTIVITY IS EXPECTED TO BE FOCUSED EVEN FURTHER
OFF TOWARD THE SOUTHWEST ON SATURDAY, WITH THE CENTRAL
SHENANDOAH VALLEY AND CENTRAL VIRGINIA HAVING THE GREATEST
CHANCE FOR A STORM. THE BACKGROUND ENVIRONMENT BOTH TODAY AND
TOMORROW HAS VERTICAL PROFILES THAT ARE DEEPLY SATURATED, WITH
MODEST FLOW THROUGH THE MID-LEVELS (AROUND 35 KNOTS OF 0-6 KM
SHEAR). DCAPE VALUES WILL BE LOW GIVEN THE SATURATED PROFILES,
BUT A WET MICROBURST OR TWO CAN'T BE RULED OUT. SPC HAS
SOUTHWESTERN PORTIONS OF THE FORECAST AREA OUTLOOKED IN A
MARGINAL RISK FOR SEVERE THUNDERSTORMS TODAY, WITH DAMAGING
WINDS BEING THE PRIMARY RISK. ON SATURDAY THE MARGINAL RISK ONLY
CLIPS HIGHLAND AN AUGUSTA COUNTIES.
FOLLOWING A GREATER SEVERE THUNDERSTORM THREAT ON SUNDAY, THERE
MAY BE ADDITIONAL THUNDERSTORMS ACROSS THE FORECAST AREA ON
MONDAY, BUT DETAILS REMAIN HIGHLY UNCERTAIN THIS FAR OUT. MOST
GUIDANCE SUGGESTS THAT A COLD FRONT WILL MOVE THROUGH LATER
MONDAY INTO MONDAY NIGHT AS HIGH PRESSURE BUILDS TO OUR NORTH.
TEMPERATURES WILL CHANGE VERY LITTLE BEHIND THIS FRONT, BUT
DRIER AIR WILL ADVECT IN FROM THE NORTH, WITH DEWPOINTS LIKELY
DROPPING INTO THE 50S ON TUESDAY. THIS DRIER AIR WILL SUPPRESS
THUNDERSTORM ACTIVITY, MOST LIKELY LEADING TO DRY CONDITIONS ON
BOTH TUESDAY AND WEDNESDAY.
AVIATION /13Z FRIDAY THROUGH TUESDAY/
PREVAILING VFR CONDITIONS ARE EXPECTED AT THE TERMINALS THROUGH
EARLY NEXT WEEK. TEMPORARY DROPS TO SUB-VFR CONDITIONS MAY BE
POSSIBLE AT TIMES DURING SHOWERS AND THUNDERSTORMS. TODAY THE
GREATEST CHANCE FOR STORMS WILL BE AT CHO, WITH CHANCES
DECREASING OFF TOWARD THE NORTH AND EAST. FOR NOW, A PROB30
GROUP FOR THUNDERSTORMS HAS BEEN INCLUDED AT CHO, WITH MENTIONS
OF SHOWERS FURTHER NORTHEAST. ADDITIONAL SHOWERS AND A
THUNDERSTORM OR TWO MAY BE POSSIBLE NEAR CHO ON SATURDAY. MORE
WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED ON
SUNDAY, WITH THE POTENTIAL FOR ALL TERMINALS TO SEE IMPACTS.
SHOWERS AND THUNDERSTORMS MAY BE POSSIBLE AGAIN ON MONDAY, WITH
DRIER CONDITIONS EXPECTED ON TUESDAY BEHIND A COLD FRONT.
WINDS WILL BE LIGHT AND VARIABLE TODAY, LIGHT OUT OF THE EAST TO
NORTHEAST ON SATURDAY, OUT OF THE SOUTH ON SUNDAY, WEST TO
NORTHWEST ON MONDAY, AND NORTH TO NORTHWEST ON TUESDAY.
MARINE
LIGHT AND VARIABLE WINDS ARE EXPECTED OVER THE WATERS TODAY,
BEFORE TURNING LIGHT OUT OF THE EAST TOMORROW. WINDS BECOME
SOUTHERLY AND INCREASE IN MAGNITUDE ON SUNDAY, WITH SMALL CRAFT
ADVISORY CONDITIONS LIKELY. SUB-SCA LEVEL NORTHWESTERLY WINDS
ARE FORECAST FOR MONDAY AND TUESDAY. AN SMW ASSOCIATED WITH
THUNDERSTORMS CAN'T BE RULED OUT ANY DAY THROUGH MONDAY. AS IT
LOOKS NOW, THE GREATEST CHANCE FOR AN AFTERNOON OR EVENING STORM
WILL BE ON SUNDAY, WITH THE LOWEST CHANCE ON SATURDAY.
TIDES/COASTAL FLOODING
WATER LEVELS ARE LARGELY EXPECTED TO STAY BELOW ACTION STAGE
THROUGH SATURDAY. THE POTENTIAL EXCEPTION COULD BE ANNAPOLIS,
WHICH COULD REACH ACTION STAGE AT THE HIGHER OF THE DAILY TIDES.
WATER LEVELS WILL START TO INCREASE IN SOUTHERLY FLOW ON
SUNDAY, WITH ANNAPOLIS POTENTIALLY APPROACHING MINOR FLOOD
STAGE.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
DISCUSSION...BRO/KJP
AVIATION...KJP
MARINE...KJP
TIDES/COASTAL FLOODING...LWX
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