530
FXUS61 KLWX 151939
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
339 PM EDT FRI AUG 15 2025
SYNOPSIS
A WEAK FRONT WILL REMAIN SOUTH OF THE AREA THROUGH THE WEEKEND
WHILE HIGH PRESSURE BUILDS TO THE NORTH. A COLD FRONT WILL
PUSH SOUTH ACROSS THE AREA SUNDAY NIGHT INTO MONDAY. THEREAFTER,
THIS BOUNDARY STALLS NEARBY THROUGH THE MIDDLE OF THE WEEK.
NEAR TERM /UNTIL 6 AM SATURDAY MORNING/
WHILE A SURFACE BOUNDARY IS WELL SOUTH OF THE AREA, A RELATIVELY
HUMID AIRMASS REMAINS IN PLACE BENEATH UPPER LEVEL RIDGING. RADAR
OBSERVATIONS ARE BEARING OUT THE ENVIRONMENT PORTRAYED BY
MODELS AND THE 12Z IAD SOUNDING. WITH EASTERLY BACKGROUND FLOW,
CONVERGENCE IS MAXIMIZED BETWEEN I-95 AND THE BLUE RIDGE AND
SECONDARILY ALONG THE EASTERN SHORE BAY BREEZE. POOR LAPSE RATES
AND DRY MID LEVEL AIR ARE RESULTING IN SHALLOWER/WEAKER
CONVECTION WITH LITTLE ADDITIONAL FORCING TO COMPENSATE. IF A
THUNDERSTORM WERE TO GROW TALLER, GUSTY WINDS WOULD BE POSSIBLE
DUE TO FAVORABLE DCAPE. WIND FIELDS ARE ALSO VERY WEAK, SO THE
CONVECTION IS BARELY DRIFTING BEFORE IT RAINS OUT. PRECIPITABLE
WATER VALUES ARE LOWER COMPARED TO THE PAST COUPLE DAYS, SO THE
THREAT FOR FLASH FLOODING APPEARS LOW UNLESS A STORM WERE TO SIT
OVER AN URBANIZED BASIN. THE FOCUS FOR ADDITIONAL DEVELOPMENT
MAY GRADUALLY DRIFT WESTWARD WITH TIME BEFORE ACTIVITY
DISSIPATES DURING THE EARLY EVENING. AFTERNOON TEMPERATURES ARE
IN THE MID 80S TO LOWER 90S. A FEW AREAS MAY NEAR 100 FOR THE
HEAT INDEX.
THE LOW LEVEL ONSHORE FLOW WILL RESULT IN LOW CLOUDS DEVELOPING
DURING THE SECOND HALF OF THE NIGHT, WHICH WILL LIKELY BANK
AGAINST THE BLUE RIDGE. SOME SPOTTY LIGHT DRIZZLE/MIST COULD
OCCUR AS WELL. WITH FEWER CLOUDS WEST OF THE BLUE RIDGE, FOG
WILL BE MORE PROBABLE, ESPECIALLY ALONG THE RIVER VALLEYS.
LOCALLY DENSE FOG IS POSSIBLE. OVERNIGHT LOWS WILL RANGE FROM
THE MID 60S TO MID 70S.
SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/
LOW CLOUDS AND FOG SHOULD LIFT BY MID SATURDAY MORNING. THE AREA
WILL REMAIN IN EAST TO SOUTHEAST FLOW BETWEEN HIGH PRESSURE OVER
NEW ENGLAND AND LOW PRESSURE ALONG THE STALLED FRONT JUST EAST
OF CAPE HATTERAS. WEAK FLOW WILL BE FOUND ALOFT ON THE EASTERN
PERIPHERY OF RIDGING IN THE MISSISSIPPI VALLEY. THE MARINE
INFLUENCE ALONG WITH FURTHER DRYING ALOFT WILL LIKELY KEEP MOST
AREAS EAST OF THE MOUNTAINS DRY. HOWEVER, TERRAIN LIFT AND SOME
MODEST INSTABILITY COULD RESULT IN SOME ISOLATED TO PERHAPS
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN THE
ALLEGHENY FRONT AND BLUE RIDGE DURING THE AFTERNOON. WHILE SLOW
MOVING, THE ISOLATED NATURE AND LOWER PRECIPITABLE WATER WILL
LIKELY MINIMIZE THE FLOOD THREAT, AND WEAKER INSTABILITY WILL
PREVENT STRONGER STORMS. AFTERNOON TEMPERATURES WILL REACH THE
UPPER 80S AND LOWER 90S. ANY CONVECTION WILL DISSIPATE BY
EVENING. THERE'S LESS OF A SIGNAL FOR FOG AND LOW CLOUDS
SATURDAY NIGHT, WITH THE HIGHEST CHANCE FOR FOG PERSISTING ALONG
THE RIVER VALLEYS WEST OF THE BLUE RIDGE. TEMPERATURES MAY TREND
A TOUCH COOLER, WITH MORE AREAS DROPPING INTO THE 60S.
THE HIGH WILL PUSH FARTHER EAST SUNDAY BUT WILL CONTINUE TO
EXTEND SOUTHWESTWARD INTO THE AREA. A STRONGER SHORTWAVE TROUGH
MOVING THROUGH CANADA WILL PUSH A COLD FRONT SOUTHWARD. THIS
FRONT WILL LIKELY REMAIN NORTH OF THE AREA UNTIL SUNDAY NIGHT,
ALTHOUGH A PREFRONTAL TROUGH MAY DEVELOP. THE BEST MID LEVEL
FORCING IS WELL TO THE NORTH AS WELL. THUS ANY ISOLATED TO
SCATTERED CONVECTION WILL LIKELY BE TIED TO THE TERRAIN DURING
THE DAYLIGHT HOURS. IT'S WORTH NOTING A FEW MODELS ARE MORE
AGGRESSIVE WITH SOUTHEASTWARD-PROPAGATING CONVECTION ACROSS THE
REMAINDER OF THE AREA, SO THIS WILL CONTINUE TO BE MONITORED.
WINDS WILL TURN MORE SOUTHERLY, OR EVEN WESTERLY DEPENDING ON
THE PREFRONTAL TROUGH POSITION. THIS WILL CAUSE SUNDAY TO BE THE
HOTTEST OF THE NEXT SEVEN WITH UPPER 80S TO MID 90S FORECAST.
SOME LOCATIONS MAY BE NEAR 100 FOR THE HEAT INDEX, BUT CURRENTLY
THINKING WE REMAIN BELOW HEAT ADVISORY CRITERIA. A FEW SHOWERS
COULD LINGER INTO THE NIGHT AS THE COLD FRONT DROPS INTO THE
AREA. WARM AND MUGGY CONDITIONS LIKELY PERSIST THOUGH AS THE
FRONT WILL NOT HAVE A STRONG INITIAL PUSH.
LONG TERM /MONDAY THROUGH FRIDAY/
UPPER LEVEL RIDGING WILL BUILD OVER THE CENTRAL CONUS AS UPPER LEVEL
TROUGHING DIGS ACROSS QUEBEC THROUGH MID WEEK. AT THE SURFACE, A
STALLED FRONT WILL REMAIN OVERHEAD YIELDING DAILY SHOWER AND
THUNDERSTORM CHANCES. HIGH TEMPERATURES ON MONDAY WILL BE IN THE 80S
ACROSS THE FORECAST AREA WITH HIGHER ELEVATIONS STAYING IN THE 70S.
TEMPERATURES WILL COOL SLIGHTLY EACH DAY WITH HIGH TEMPERATURES IN
THE LOW 80S TUESDAY THROUGH THURSDAY WITH HIGHER ELEVATIONS IN THE
60S TO LOW 70S.
BY MIDWEEK, HURRICANE ERIN IS FORECAST TO TRACK NORTHWARD ACROSS THE
ATLANTIC OFF THE COAST OF THE SOUTHEAST US WHILE THE FRONTAL
ZONE SHIFTS A BIT FURTHER SOUTH. THEREFORE RAIN CHANCES MAY
DECREASE SOMEWHAT WHILE BELOW NORMAL TEMPERATURES CONTINUE.
MONITOR NATIONAL HURRICANE CENTER PRODUCTS FOR THE LATEST
INFORMATION ON ERIN.
AVIATION /19Z FRIDAY THROUGH WEDNESDAY/
SHOWERS AND A COUPLE THUNDERSTORMS HAVE DEVELOPED FROM THE IAD
AREA NORTHWARD IN A CONVERGENCE ZONE. ACTIVITY HAS BEEN
RELATIVELY SHALLOW THOUGH, SO DOWNPOURS WITH REDUCED VISIBILITY,
A FEW LIGHTNING STRIKES, AND PERHAPS LOCALLY GUSTY SURFACE
WINDS ARE THE MAIN THREATS. THE FOCUS WILL LIKELY DRIFT WESTWARD
WITH TIME, BUT PERHAPS NOT REACHING MRB/CHO BEFORE DISSIPATION
OCCURS TOWARD SUNSET. A FEW SHOWERS HAVE ALSO DEVELOPED ALONG
THE EASTERN SHORE BUT IT'S QUESTIONABLE WHETHER ANYTHING CAN
SURVIVE TO THE WESTERN SHORE. HAVE THUS MAINTAINED PROB30 GROUPS
FOR MRB, CHO, BWI, AND MTN AS CONFIDENCE IS LOW IN DIRECT
IMPACTS.
BACKGROUND EASTERLY WINDS WILL PROMOTE LOW CLOUDS DEVELOPING
LATE TONIGHT, ESPECIALLY EAST OF THE BLUE RIDGE. HAVE INTRODUCED
IFR CONDITIONS GIVEN GOOD MODEL AGREEMENT, ALTHOUGH BWI/MTN HAVE
THE LOWEST CONFIDENCE. VISIBILITY MAY ALSO BE REDUCED IN PATCHY
MIST AND DRIZZLE. MRB HAS A GREATER CHANCE OF SEEING FOG. IF LOW
CLOUDS HOLD OFF THERE, SOME DENSE FOG IS POSSIBLE. CEILINGS AND
VISIBILITY SHOULD IMPROVE BY MID SATURDAY MORNING.
FOR SATURDAY, ANY CONVECTIVE CHANCES ARE MORE TIED TO THE
TERRAIN. HOWEVER, A FEW OF THESE STORMS COULD AFFECT CHO OR MRB.
OTHERWISE, VFR CONDITIONS AND LIGHT SOUTHEAST WINDS ARE
EXPECTED DURING THE DAYTIME. THERE'S LESS OF A LOW CLOUD AND FOG
SIGNAL SATURDAY NIGHT, ALTHOUGH MRB AND PERHAPS CHO COULD STILL
HAVE SOME FOG DEVELOP. A COLD FRONT WILL SLOWLY APPROACH SUNDAY
INTO SUNDAY NIGHT. RELATIVELY SPEAKING, MRB HAS THE GREATEST
CHANCE FOR THUNDERSTORMS DURING THIS PERIOD, BUT EVEN THAT IS A
20 TO 30 PERCENT CHANCE.
PREVAILING VFR CONDITIONS ARE EXPECTED MONDAY AND TUESDAY WITH THE
EXCEPTION BEING DURING PRECIPITATION. DAILY RAIN SHOWERS AND A
POSSIBLE THUNDERSTORM ARE FORECAST BOTH DAYS, ALTHOUGH COVERAGE WILL
BE LIMITED. NORTHEAST WINDS ON MONDAY SHIFT TO SOUTHEAST ON TUESDAY,
BLOWING 5 TO 10 KNOTS EACH AFTERNOON.
MARINE
BACKGROUND WIND FIELDS WILL LIKELY STAY BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH THE WEEKEND. A FEW SHOWERS AND
THUNDERSTORMS MAY PRODUCE GUSTY WINDS THIS AFTERNOON AND EARLY
EVENING, BUT SO FAR THE FOCUS FOR STRONGER ACTIVITY APPEARS TO
BE INLAND. EASTERLY WINDS CONTINUE THROUGH TONIGHT BEFORE
TURNING SOUTHEASTERLY SATURDAY. A BRIEF UPTICK IN WINDS SATURDAY
EVENING COULD HAVE GUSTS THAT NEAR ADVISORY LEVEL. WINDS BECOME
SOUTH TO SOUTHWEST SUNDAY, WITH ANOTHER SLIGHT INCREASE POSSIBLE
SUNDAY EVENING. A FEW SHOWERS OR STORMS COULD REACH THE WATERS
LATE SUNDAY, BUT STRONG ACTIVITY APPEARS UNLIKELY.
WINDS ARE EXPECTED TO STAY BELOW SMALL CRAFT ADVISORY MONDAY AND
TUESDAY. RAIN SHOWERS AND AN ISOLATED THUNDERSTORM ARE POSSIBLE OVER
THE WATERS EACH DAY.
TIDES/COASTAL FLOODING
ELEVATED TIDAL ANOMALIES LOOK TO CONTINUE THROUGH THE WEEKEND
WITH SOME UPTICK FORECAST DUE TO ONSHORE WINDS. ANNAPOLIS MAY
APPROACH OR EXCEED MINOR FLOOD FOR MULTIPLE UPCOMING TIDE
CYCLES, STARTING WITH THIS EVENING. WHILE OTHER LOCATIONS
AREN'T CURRENTLY FORECAST TO FLOOD, SOME COULD COME CLOSE,
ESPECIALLY SUNDAY EVENING. A PASSING COLD FRONT SHOULD REDUCE
WATER LEVELS SLIGHTLY HEADING INTO MONDAY.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
SYNOPSIS...ADS
NEAR TERM...ADS
SHORT TERM...ADS
LONG TERM...AVS
AVIATION...ADS/AVS
MARINE...ADS/AVS
TIDES/COASTAL FLOODING...ADS
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