571
FXUS61 KLWX 160131
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
931 PM EDT SAT AUG 15 2026
WHAT HAS CHANGED
A FLOOD WATCH REMAINS IN EFFECT FOR GARRETT COUNTY FROM 6 AM
SUNDAY TO 12 AM MONDAY. ELSEWHERE, WE CONTINUE TO MONITOR THE
POTENTIAL FOR BOTH SEVERE THUNDERSTORMS AND ISOLATED INSTANCES
OF FLASH FLOODING ON SUNDAY.
KEY MESSAGES
- 1) SEVERE THUNDERSTORMS AND SOME INSTANCES OF FLASH FLOODING
ARE POSSIBLE ON SUNDAY.
- 2) SEASONABLE CONDITIONS CONTINUE THROUGH THE WEEK WITH
A BREAK IN THUNDERSTORM CHANCES TUESDAY AND WEDNESDAY.
DISCUSSION
KEY MESSAGE 1...SEVERE THUNDERSTORMS AND SOME INSTANCES OF
FLASH FLOODING ARE POSSIBLE ON SUNDAY.
SUNDAY IS SHAPING UP TO BE AN ACTIVE WEATHER DAY ACROSS THE REGION.
SHOWERS AND EMBEDDED STRONG TO SEVERE THUNDERSTORMS ARE NOTED ON
RADAR NEAR COLUMBUS, OHIO AND BACK INTO NORTHWESTERN OHIO. THIS
ACTIVITY WILL CONTINUE TO MOVE TOWARD THE EAST-SOUTHEAST OVER
THE NEXT SEVERAL HOURS, CROSSING OHIO, AND MOVING INTO NORTHERN
WEST VIRGINIA AND SOUTHWEST PENNSYLVANIA A FEW HOURS BEFORE
DAYBREAK. A COUPLE OF THESE SHOWERS COULD BE HEAVY AND REACH
WESTERN MARYLAND AND PARTS OF NORTHEASTERN WEST VIRGINIA IN OUR
FORECAST AREA AROUND DAYBREAK OR SHORTLY BEFORE. THE MAIN THREAT
WILL BE BRIEF GUSTY WINDS AND HEAVY RAIN. AS FOR THE REMAINDER
OF SUNDAY INTO SUNDAY EVENING, ADDITIONAL ROUNDS OF SHOWERS AND
STRONG TO SEVERE THUNDERSTORMS COULD DEVELOP WITH MULTIPLE WAVES
OF MID-LEVEL ENERGY. THE MAIN THREATS WILL BE DAMAGING WIND
GUSTS, LOCALLY HEAVY RAINFALL THAT COULD LEAD TO LOCALIZED FLASH
FLOODING, AND A POSSIBLE TORNADO OR TWO. IN PERSPECTIVE TO
SURFACE BOUNDARY RELATIVE TO THE MID-LEVEL WAVES OF ENERGY, A
WARM FRONT WILL PUSH NORTHWARD SUNDAY MORNING TO MIDDAY, BEFORE
AN AREA OF LOW PRESSURE CONNECTS TO IT, FOLLOWED BY A COLD
FRONT. THIS TRIFECTA OF SYNOPTIC FEATURES AND BOUNDARIES WILL
JUST ENHANCE THE POSSIBILITY OF SEVERE WEATHER SUNDAY AND SUNDAY
NIGHT. THE STORMS PREDICTION CENTER HAS AN AREA FROM CUMBERLAND,
MARYLAND TO MANASSAS, VIRGINIA TO ST. MARY'S MARYLAND AND ALL
AREAS TO THE SOUTHWEST OF THIS LINE IN A SLIGHT RISK OF SEVERE
THUNDERSTORMS. ALL AREAS TO THE NORTHEAST OF THIS LINE IS IN A
MARGINAL RISK. THE WEATHER PREDICTION CENTER HAS GARRETT COUNTY
AND PARTS OF WESTERN GRANT AND PENDLETON COUNTY IN A SLIGHT RISK
FOR EXCESSIVE RAINFALL. AREAS TO THE EAST AND UP TO US 15 IS IN
A MARGINAL RISK FOR EXCESSIVE RAINFALL. A FLOOD WATCH REMAINS IN
EFFECT FOR GARRETT COUNTY IN WESTERN MARYLAND. THIS IS EFFECT
FROM 6AM TO MIDNIGHT THROUGH THE DAY SUNDAY INTO SUNDAY EVENING.
KEY MESSAGE 2...SEASONABLE CONDITIONS CONTINUE THROUGH THE WEEK WITH
A BREAK IN THUNDERSTORM CHANCES TUESDAY AND WEDNESDAY.
WINDS WILL SHIFT WEST OR NORTHWEST BY MONDAY, BUT THE ACTUAL COLD
FRONT/MOISTURE GRADIENT WILL BE LAGGING IN THE OHIO VALLEY. IT'S
POSSIBLE A FEW SHOWERS AND THUNDERSTORMS FORM MONDAY AS THE FRONT
MOVES THROUGH, ALTHOUGH THE DOWNSLOPING FLOW AND MODEST MID LEVEL
LAPSE RATES WILL LIKELY LIMIT COVERAGE. ABOVE NORMAL TEMPERATURES
AND HUMID CONDITIONS WILL CONTINUE UNTIL THE FRONT CLEARS THE AREA
MONDAY NIGHT.
UPPER-LEVEL ZONAL FLOW BRINGING DRIER AIR FROM THE GREAT LAKES WILL
BE IN PLACE TUESDAY AND WEDNESDAY, CREATING A BREAK IN THE RAIN AND
THUNDERSTORMS. TEMPERATURES AND HUMIDITY LEVELS WILL DROP A BIT BUT
REMAIN NEAR SEASONABLE AVERAGES.
MEANWHILE, AN UPPER-LEVEL TROUGH WILL BEGIN TO FORM OVER THE
NORTHERN PLAINS AND THEN TRACK ACROSS THE GREAT LAKES LATE IN THE
WEEK, WITH A STRONG COLD FRONT POTENTIALLY APPROACHING THE MID-
ATLANTIC BETWEEN THURSDAY AND FRIDAY. THIS FRONT COULD EVEN STALL
ACROSS THE AREA INTO NEXT WEEKEND, BRINGING PERSISTENT CHANCES FOR
SHOWERS AND THUNDERSTORMS. AT THIS TIME, IT'S UNCLEAR IF THE
POSITION OF SYNOPTIC FEATURES AND INSTABILITY WILL BE SUFFICIENT FOR
A THREAT OF SEVERE WEATHER OR FLOODING. FOR NOW, THIS WILL BE A
FEATURE TO CONTINUE TO MONITOR AS THE SYNOPTIC SETUP BECOMES MORE
DEFINED. TEMPERATURES MAY FLUCTUATE A LITTLE DEPENDING ON WHAT SIDE
OF THE FRONT WE'RE ON, BUT LIKELY FALL SOME BY NEXT WEEKEND ASSUMING
THE FRONT PUSHES TO THE SOUTHEAST.
AVIATION /01Z SUNDAY THROUGH THURSDAY/
VFR CONDITIONS ARE EXPECTED TONIGHT. MVFR CEILINGS AND SHOWERS
MOVE IN TOMORROW MORNING FROM WEST TO EAST, ALONG WITH
POTENTIALLY A FEW EMBEDDED THUNDERSTORMS. PROB30 GROUPS HAVE
BEEN ADDED FOR NOW TO ACCOUNT FOR THIS ACTIVITY. THERE MAY BE A
BRIEF LULL BEFORE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
MOVES IN FROM THE WEST TOMORROW EVENING. THESE SHOWERS AND
STORMS MAY LINGER THROUGH THE FIRST HALF OF THE NIGHT,
ESPECIALLY FURTHER EAST. THEREAFTER, PREVAILING VFR CONDITIONS
ARE EXPECTED THROUGH MONDAY. THERE MAY ALSO BE A CHANCE FOR A
PASSING SHOWER OR STORM ON MONDAY AFTERNOON, BUT COVERAGE IS
EXPECTED TO BE MUCH LOWER COMPARED TO SUNDAY.
WINDS TURN LIGHT OUT OF THE SOUTH TO SOUTHEAST TONIGHT, BEFORE
PICKING UP AND GUSTING TO AROUND 15-20 KNOTS OUT OF THE SOUTH
TOMORROW AFTERNOON. WINDS THEN SHIFT TO OUT OF THE NORTHWEST ON
MONDAY.
PREVAILING VFR CONDITIONS ARE ANTICIPATED TUESDAY THROUGH WEDNESDAY
WITH HIGH PRESSURE. POTENTIAL SHOWERS AND THUNDERSTORMS RE-ENTER THE
FORECAST THURSDAY.
MARINE
WINDS TURN SOUTHERLY LATER TONIGHT INTO TOMORROW. THOSE
SOUTHERLY WINDS SHOULD REACH SCA LEVELS OVER ALL WATERS TOMORROW
AFTERNOON. THE SCA LEVEL WINDS SHOULD END OVER THE NARROWER
WATERS OF THE MIDDLE AND UPPER TIDAL POTOMAC AFTER SUNSET, BUT
CONTINUE ACROSS THE LOWER TIDAL POTOMAC AND BAY THROUGH MUCH OF
NIGHT. SCAS HAVE BEEN ISSUED FOR ALL WATERS. SUB-SCA LEVEL
NORTHWESTERLY WINDS ARE EXPECTED ON MONDAY. SMWS MAY POTENTIALLY
BE NEEDED AS THUNDERSTORMS MOVE OVER THE WATERS ON BOTH SUNDAY
AND MONDAY, ALTHOUGH COVERAGE OF STORMS IS FORECAST TO BE MUCH
GREATER ON SUNDAY.
NORTH TO NORTHWEST WINDS CONTINUE FOR TUESDAY BUT LIKELY REMAIN
BELOW SCA LEVELS. AS HIGH PRESSURE DEPARTS, WINDS TURN SOUTHERLY ON
WEDNESDAY, AND CHANNELING MAY BRING MARGINAL SCA CONDITIONS ALONG
THE BAY DURING THE EVENING/OVERNIGHT. A COLD FRONT MAY BRING SOME
THUNDERSTORMS ON THURSDAY.
TIDES/COASTAL FLOODING
WATER LEVELS INCREASE EVERYWHERE TOMORROW AS SOUTHERLY WINDS
PICK UP. MINOR FLOODING MAY BE POSSIBLE WITH TOMORROW EVENING'S
HIGH TIDE AT ANNAPOLIS. ELSEWHERE, MANY LOCATIONS WILL RISE INTO
ACTION STAGE. WATER LEVELS ARE FORECAST TO DECREASE FOR MONDAY
INTO TUESDAY AS WINDS TURN OUT OF THE WEST AND THEN NORTHWEST.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY FROM NOON SUNDAY TO 6 AM EDT MONDAY FOR
MDZ008.
FLOOD WATCH FROM 6 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR
MDZ509-510.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON SUNDAY TO 6 AM EDT MONDAY FOR
ANZ530>534-537>543.
SMALL CRAFT ADVISORY FROM NOON TO 8 PM EDT SUNDAY FOR ANZ535-
536.
DISCUSSION...ADS/KLW/KJP
AVIATION...ADS/KLW/KJP
MARINE...ADS/KLW/KJP
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