032
FXUS61 KLWX 160418
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1218 AM EDT SAT AUG 16 2025
.SYNOPSIS
A WEAK FRONT WILL REMAIN SOUTH OF THE REGION THROUGH THE WEEKEND
WHILE BRIEF HIGH PRESSURE BUILDS IN FROM THE NORTH. THIS WILL LEAD
TO A CONTINUATION OF LATE SUMMERTIME HEAT AND HUMIDITY ALONG WITH
DECREASED CHANCES FOR THUNDERSTORMS. A COLD FRONT WILL APPROACH THE
AREA SUNDAY NIGHT INTO MONDAY BEFORE STALLING OVER THE REGION
TUESDAY INTO WEDNESDAY. A STRONGER FRONT WILL CROSS THE AREA
WEDNESDAY INTO THURSDAY WITH A COOLDOWN EXPECTED LATE NEXT WEEK.
NEAR TERM /THROUGH SATURDAY NIGHT/
ANY RESIDUAL SHOWER OR THUNDERSTORM ACTIVITY WILL QUICKLY COME
TO AN END WITH QUIET CONDITIONS FOR THE REMAINDER OF THE EVENING
AND INTO THE OVERNIGHT. SKIES WILL TREND PARTLY TO MOSTLY
CLOUDY EAST OF THE BLUE RIDGE WITH LOW CLOUDS LIKELY DEVELOPING
DURING THE SECOND HALF OF THE NIGHT AS MOISTURE BANKS AGAINST
THE BLUE RIDGE. SOME LIGHT DRIZZLE/MIST/FOG ALSO CANNOT BE RULED
OUT GIVEN THE MOISTENED MARINE AIRMASS OVERHEAD. AREAS WEST OF
THE BLUE RIDGE WILL LIKELY SEE PARTLY CLOUDY TO MOSTLY CLEAR
SKIES WITH AREAS OF FOG ACROSS THE RIVER VALLEYS. SOME OF THIS
FOG WILL BE LOCALLY DENSE ESPECIALLY ACROSS THE ALLEGHENIES AND
DOWN ACROSS PORTIONS OF THE SHENANDOAH VALLEY. LOWS TONIGHT WILL
RANGE FROM THE LOW TO MID 60S OVER THE MOUNTAINS TO MID 70S IN
THE I-95 CORRIDOR.
LOW CLOUDS, FOG, AND DRIZZLE SHOULD QUICKLY MIX OUT BY MID TO LATE
SATURDAY MORNING. EAST TO SOUTHEAST ONSHORE FLOW WILL REMAIN WITH
HIGH PRESSURE OVER NEW ENGLAND/QUEBEC WEDGING SOUTH AND LOW PRESSURE
OFF THE NORTH CAROLINA COAST. WEAK FLOW WILL REMAIN ALOFT ALONG THE
EASTERN PERIPHERY OF THE SUBTROPICAL RIDGE BUILDING IN FROM THE
MISSISSIPPI RIVER VALLEY. THIS SHOULD KEEP MOST LOCATIONS DRY
OUTSIDE OF THE TERRAIN AND EASTERN/WESTERN SHORE OF THE BAY WHERE AN
ISOLATED SHOWER/STORM REMAINS POSSIBLE. HIGHEST CONFIDENCE PER
CURRENT HI-RES CAMS SHOW 20-30 PERCENT CHANCES FOR A SPOTTY SHOWER
OR T-STORM DEVELOPING BETWEEN THE ALLEGHENIES AND BLUE RIDGE
SATURDAY AFTERNOON. ANY CONVECTION WILL BE SHORT LIVED GIVEN THE
LACK OF A FORCING MECHANISM AND MARINE INFLUENCE OVER THE REGION.
ANY FLOOD/SEVERE THREAT WILL BE MINIMIZED WITH LOWER PRECIPITABLE
WATER VALUES AND LACK OF INSTABILITY GIVEN THE ONSHORE FLOW
INFLUENCE THAT WILL REMAIN IN PLACE ESPECIALLY EAST OF THE BLUE
RIDGE. HIGH TEMPERATURES SATURDAY 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.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
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.
UPPER LEVEL RIDGING WILL BUILD OVER THE CENTRAL CONUS AS UPPER LEVEL
TROUGHING DIGS SOUTH FROM EASTERN CANADA TO START THE NEW WORKWEEK.
AT THE SURFACE, A STALLED BOUNDARY WILL REMAIN YIELDING A
CONTINUATION OF THE HEAT, HUMIDITY, AND DIURNAL THUNDERSTORM
CHANCES. STORM CHANCES MONDAY WILL RANGE BETWEEN 20 TO 30 PERCENT
WITH A FOCUS MAINLY WEST OF THE BLUE RIDGE AND DOWN INTO THE
CENTRAL/SOUTHWEST VA WHERE MOST OF THE CURRENT 18/00Z GUIDANCE HAS
THE STALLED FRONT RESIDING. HIGH TEMPERATURES ON MONDAY WILL BE IN
THE 80S ACROSS THE FORECAST AREA WITH HIGHER ELEVATIONS STAYING IN
THE 70S. LOWS MONDAY NIGHT WILL FALL BACK INTO THE MID TO UPPER 60S
OUTSIDE THE MOUNTAINS.
LONG TERM /TUESDAY 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. 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 /02Z SATURDAY THROUGH WEDNESDAY/
ANY RESIDUAL SHOWER AND THUNDERSTORM ACTIVITY SHOULD COME TO
END AFTER 01Z. VFR CONDITIONS WILL PREVAIL UNTIL THEN WITH SUB-
VFR CIGS AND VSBYS LIKELY DEVELOPING OVERNIGHT ESPECIALLY AT
TERMINALS EAST OF THE BLUE RIDGE. THIS IS DUE LARGELY IN PART TO
EAST TO SOUTHEAST ONSHORE FLOW WHICH WILL PROMOTE LOW CLOUDS
ACROSS THE CORRIDOR AND BACK TOWARD A LINE THAT EXTENDS FROM
HGR/MRB SOUTH TO KCHO. CURRENT CAMS SUGGEST GOOD AGREEMENT ON
IFR CONDITIONS IMPACTING KDCA, KCHO, KIAD, AND KMRB LATE TONIGHT
INTO EARLY SATURDAY MORNING. THERE IS SLIGHTLY LOWER CONFIDENCE
AT KBWI AND KMTN. HIGHEST CONFIDENCE FOR FOG IS KMRB AND KSHD
WHERE SKIES LOOK TO CLEAR FOR A PERIOD OF TIME BEFORE PASSING
CLOUDS FILL IN. SOME OF THIS FOG WILL BE LOCALLY DENSE WITH THE
GREATEST COVERAGE OF FOG TIED TO THE ALLEGHENIES, CATOCTINS, AND
PORTIONS OF THE SHENANDOAH VALLEY. SOME LIGHT DRIZZLE AND MIST
ALSO CANNOT BE RULED OUT AT TERMINALS EAST OF THE BLUE RIDGE
GIVEN THE MARINE ONSHORE INFLUENCE OVERHEAD. CEILINGS AND
VISIBILITY SHOULD IMPROVE BY MID SATURDAY MORNING.
CONVECTIVE CHANCES SATURDAY DECREASE EVEN FURTHER AMONGST THE
TERMINALS AND SHOULD BE RELEGATED WELL WEST OF THE CORRIDOR. A
SPOTTY AFTERNOON SHOWER OR T-STORM CANNOT BE RULED AT KCHO AND KMRB,
BUT CONFIDENCE IS LOW (20-30 PERCENT). VFR CONDITIONS SHOULD PREVAIL
FOR MOST WITH LIGHT SOUTHEAST WINDS LESS THAN 10KTS. 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. ADDITIONAL RAIN CHANCES ARE
LIKELY WEDNESDAY INTO THURSDAY AS A STRONGER FRONT CROSS THE REGION.
MARINE
SUB-SCA LEVEL WINDS ARE EXPECTED TO CONTINUE THROUGH THE
WEEKEND. EASTERLY WINDS WILL CONTINUE THROUGH TONIGHT BEFORE
TURNING SOUTHEAST 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. OUTSIDE OF
THE WINDS AND POTENTIAL SHOWER/T-STORM ACTIVITY EXPECT SOME
MARINE FOG EARLY SATURDAY MORNING AND AGAIN SUNDAY MORNING
ESPECIALLY IN THE SHELTERED INLETS/HARBORS. ANY FOG/LOW CLOUDS
SHOULD BURN OFF FAIRLY QUICKLY DURING THE MID-MORNING PERIOD.
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/EST
SHORT TERM...ADS
LONG TERM...AVS
AVIATION...ADS/AVS/EST
MARINE...ADS/AVS/EST
TIDES/COASTAL FLOODING...EST
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