434
FXUS61 KLWX 220802
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
402 AM EDT SAT AUG 22 2026
WHAT HAS CHANGED
UPDATE ON THE CURRENT SHOWERS DEVELOPING OVER SOUTHERN MD AND
THE VA PIEDMONT. FLOODING THREAT REMAINS LIMITED, BUT WILL NEED
TO BE MONITORED CLOSELY AS THE AXIS OF HEAVIER RAIN SETS UP
THROUGHOUT THE MORNING.
ALSO UPDATED AVIATION AND MARINE DISCUSSIONS SUBSTANTIALLY TO
ADD MORE DETAILS ON TODAY'S SETUP.
KEY MESSAGES
- 1) SHOWERS AND THUNDERSTORMS TODAY WITH THE POTENTIAL FOR
HEAVY RAINFALL AND ISOLATED INSTANCES OF FLASH FLOODING.
- 2) DRY CONDITIONS ANTICIPATED SUNDAY THROUGH EARLY NEXT WEEK.
- 3) WARMER AND MORE HUMID CONDITIONS RETURN MID-WEEK, WITH
THUNDERSTORM CHANCES RETURNING BY THURSDAY.
DISCUSSION
KEY MESSAGE 1...SHOWERS AND THUNDERSTORMS TODAY WITH THE POTENTIAL FOR
HEAVY RAINFALL AND ISOLATED INSTANCES OF FLASH FLOODING.
LATEST SURFACE ANALYSIS STILL DEPICTS A STALLED FRONTAL
BOUNDARY OFF TO OUR SOUTH AND EAST. SATELLITE IMAGERY DEPICTS AN
INFLUX OF MOISTURE INTO THE REGION EAST OF AN APPROACHING UPPER
TROUGH AXIS. WE ARE STARTING TO SEE SOME HEAVIER SHOWERS
DEVELOP IN THE RIGHT ENTRANCE REGION OF A 90 KNOT UPPER-LEVEL
JET. LOW PRESSURE IS DEVELOPING OVER THE CAROLINA, BUT REMAINS
VERY LOOSELY DEVELOPED AT THIS STAGE. AT ANY RATE, ALL OF THESE
FEATURES ARE EXPECTED TO EVOLVE THROUGHOUT THE DAY, GIVING A
CONTINUOUS THREAT FOR SHOWERS AND THUNDERSTORMS THROUGH THE
AFTERNOON HOURS.
THE LATEST SPC MESOANALYSIS IS STARTING TO HONE IN ON AN AREA
GENERALLY SOUTHEAST OF THE I-95 CORRIDOR. PWATS IN THIS REGION
REMAIN IN THE 1.6-1.8 INCH RANGE, WITH A DECENT OVERLAP OF LOW-
LEVEL MOISTURE CONVERGENCE AND PPP. CURRENT FORECAST CALLS FOR
1-2" SOMEWHERE ALONG/SOUTHEAST OF I-95, BUT COULD SEE SOME
LOCALLY HIGHER AMOUNTS. AS IT STANDS RIGHT NOW, THE REGION OF
CONCERN SHOULD FALL JUST SOUTHEAST OF THE METRO AREAS. SANDY
SOILS AND ANTECEDENT LOW SOIL MOISTURE IN THIS REGION SHOULD
MITIGATE THE FLOODING THREAT. HOWEVER, THE ONE EXCEPTION WILL BE
IF THE HEAVIEST AXIS EITHER SHIFTS NORTH INTO ST. MARYS COUNTY,
WHERE RECENT HEAVY RAINS LEAVE THAT AREA SLIGHTLY MORE
SUSCEPTIBLE TO FLOODING. ADDITIONALLY, IF THE AXIS DOES SHIFT
NORTH INTO THE METROS, FLASH FLOODING COULD BECOME AN ISSUE.
NO FLOOD WATCH AT THIS TIME, AS CONFIDENCE REMAINS HIGHER THAT
THE HIGHEST RAIN TOTALS WILL FALL IN LESS SUSCEPTIBLE AREAS. IF
THAT CHANGES, ONE MAY BE CONSIDERED LATER THIS MORNING.
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS THERE COULD BE
A LULL, BUT THERE REMAINS A CHANCE FOR POP-UP SHOWERS AND STORMS
PRETTY MUCH ANYWHERE DURING THIS PERIOD.
BY EVENING, ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL
APPROACH THE APPALACHIAN MOUNTAINS AND MAY MAKE TO AREAS EAST OF
THE BLUE RIDGE MOUNTAINS OVERNIGHT INTO EARLY SUNDAY. SEVERE
THREAT IS LOW WITH THESE, AS THEY WILL BE RUNNING INTO STABLE
SURFACE AIR. HOWEVER, THEY COULD BRING SOME HEAVY RAINFALL AND
THUNDER. SOME FOG MAY THEN DEVELOP IN THE VALLEYS AND VA
PIEDMONT, BUT IT WILL HAVE TO DO SO PRIOR TO THE ARRIVAL OF THE
FRONT.
BY SUNDAY MORNING THE COLD FRONT WILL BE CROSSING THE AREA WITH
DRY AIR ADVECTION ENSUING IN STRENGTHENING NW WINDS. HOWEVER,
THERE COULD STILL BE ENOUGH MOISTURE AND LIFT TO SPARK A FEW
SHOWERS, BUT OVERALL DRYING CONDITIONS ARE EXPECTED THROUGHOUT
THE DAY.
KEY MESSAGE 2...DRY CONDITIONS ANTICIPATED SUNDAY THROUGH EARLY
NEXT WEEK.
DEWPOINTS DROP SHARPLY IN THE WAKE OF THE COLD FRONT MONDAY AS DRY
AIR MOVES INTO THE REGION FROM THE MIDWEST. SURFACE HIGH PRESSURE
WILL BEGIN TO BUILD OVER THE APPALACHIANS AND TRACK EAST OVER THE
NEXT COUPLE OF DAYS, WITH CONDITIONS FEELING BRIEFLY FALL-LIKE AS
TEMPERATURES RANGE SLIGHTLY BELOW AVERAGE FOR AUGUST. OVERNIGHT
LOWS RANGE LARGELY IN THE 50S THROUGHOUT THE REGION BY TUESDAY,
AND SUB-60F DEWPOINTS COULD PERSIST UNTIL MIDWEEK.
KEY MESSAGE 3...WARMER AND MORE HUMID CONDITIONS RETURN MID-
WEEK, WITH THUNDERSTORM CHANCES RETURNING BY THURSDAY.
AS THE WEEK CONTINUES, A BROAD UPPER-LEVEL TROUGH WILL BEGIN TO FORM
OVER THE GREAT LAKES AND TRACK TOWARDS THE MID-ATLANTIC BY THURSDAY.
AS THE ASSOCIATED SURFACE LOW APPROACHES THE REGION, MOIST AIR FROM
THE SOUTH WILL FLOW INTO THE AREA, BRINGING BACK AN INCREASE IN
HUMIDITY & TEMPERATURES BACK TO LATE-AUGUST NORMALS. AS THIS LOW
TRACKS THROUGH, EXPECT SHOWER & THUNDERSTORM CHANCES TO INCREASE AS
THE ASSOCIATED COLD FRONT TRACKS OFFSHORE BY THE END OF THE WEEK.
MEDIUM-RANGE SEVERE INDICES STILL MAINTAIN A LOW-END NON-ZERO
CHANCE FOR STRONGER CONVECTION AS THIS FRONT MOVES THROUGH.
TEMPERATURES RISE BACK INTO THE UPPER 80S BY THURSDAY.
AVIATION /08Z SATURDAY THROUGH WEDNESDAY/
LOW PRESSURE TRACKING ALONG A STALLED BOUNDARY TO OUR SOUTHEAST
WILL PUSH SHOWERS AND SOME EMBEDDED STORMS INTO THE REGION LATER
THIS MORNING. STILL LOTS OF UNCERTAINTY WITH JUST HOW MUCH RAIN
FALLS AND HOW INTENSE ANY SHOWERS WILL BE THAT REACH THE
TERMINALS. LOW CLOUDS WILL ALSO BE AN ISSUE, WHICH MAKES
RESTRICTIONS LIKELY. THOUGH, IF THE SHOWERS AND UP BEING LESS
INTENSE, IT IS POSSIBLE THAT CONDITIONS REMAIN LOW-END MVFR
RATHER THAN DROPPING TO IFR. LATEST TAFS REFLECT SOME
UNCERTAINTY THERE, WITH AREAS FURTHER EAST A BIT MORE LIKELY
THAN THOSE TO THE WEST.
ANOTHER LOW PRESSURE SYSTEM OVER THE GREAT LAKES REGION WILL
PUSH A COLD FRONT THROUGH THE REGION LATER TONIGHT. THIS WILL
BRING ANOTHER LINE OF SHOWER AND STORMS ALONG WITH IT,
PERSISTING THROUGH THE EARLY OVERNIGHT HOURS. THIS COULD BRING
ANOTHER PERIOD OF RESTRICTIONS. IN THE WAKE OF THE RAIN, FOG IS
EXPECTED TO DEVELOP AT CHO AND PROBABLY MRB AS WELL SUNDAY
MORNING. IT IS POSSIBLE IT COULD CREEP INTO IAD AS WELL.
PREDOMINANTLY VFR CONDITIONS ARE ANTICIPATED ACROSS TERMINALS
SUNDAY THROUGH WEDNESDAY. WINDS ON SUNDAY THROUGH TUESDAY REMAIN
OUT OF THE WNW TO NW, GUSTING UP TO 20 KNOTS DURING THE
AFTERNOON HOURS (EXCEPT CHO WHICH WILL BE 5 TO 8 KNOTS LOWER).
BEGINNING WEDNESDAY AFTERNOON, WINDS SHIFT OUT OF THE SOUTH, BUT
SHOULD BE A BIT WEAKER. ADDITIONALLY, A FEW SHOWERS AND
THUNDERSTORMS BECOME POSSIBLE AHEAD OF AN APPROACHING COLD FRONT
THAT COULD BRING TEMPORARILY REDUCED CONDITIONS INTO THE EVENING
AND PERHAPS OVERNIGHT HOURS.
MARINE
EASTERLY WINDS EXPECTED TODAY AROUND 5 TO 10 KNOTS WITH GUSTS UP
TO 15 KNOTS AS LOW PRESSURE SLIDES BY TO OUR SOUTHEAST. SCA
CONDITIONS ARE NOT EXPECTED, HOWEVER ANY HEAVIER SHOWERS OR
STORMS COULD BRING DOWN GUSTS AROUND 20 TO 25 KNOTS AT TIMES
THROUGHOUT THE DAY. THESE WOULD LIKELY COME IN SHORT BURSTS, AND
SHOULD BE FEW AND FAR BETWEEN. ANOTHER LINE OF SHOWERS AND
STORMS MOVES IN LATE TONIGHT, BUT AGAIN SHOULD NOT BRING ANY
SUBSTANTIAL WIND GUSTS AS WE WILL BE STABLE.
WINDS TURN OUT OF THE WNW SUNDAY THROUGH TUESDAY, AND SHOULD
REMAIN SUB-SCA THROUGHOUT THAT PERIOD. A FEW GUSTS NEAR 18 KNOTS
ARE POSSIBLE, ESPECIALLY FURTHER NORTH, BUT NOT SEEING A
PROLONGED PERIOD ENOUGH TO WARRANT AN SCA AT THIS TIME.
WINDS SHIFT SOUTHERLY BY WEDNESDAY, WITH WINDS GUSTING ABOVE
SCA THRESHOLDS LATER THAT EVENING IN A CLASSIC SOUTHERLY
CHANNELING EVENT AHEAD OF AN APPROACHING COLD FRONT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
DISCUSSION...CJL/SRT
AVIATION...CJL/SRT
MARINE...CJL/SRT
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