097
FXUS61 KLWX 230027
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
827 PM EDT TUE JUL 22 2025
SYNOPSIS
DRY CONDITIONS AND LOW HUMIDITY CONTINUE THROUGH WEDNESDAY AS BROAD
CANADIAN HIGH PRESSURE DRIFTS OFFSHORE. THE HEAT AND HUMIDITY BUILDS
AGAIN THURSDAY INTO THE WEEKEND, ALONG WITH A CHANCE OF THUNDERSTORMS.
THUNDERSTORM CHANCES CONTINUE INTO EARLY NEXT WEEK AS A FRONT
STALLS NEARBY.
NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/
IT'S BEEN A TRUE TREAT OF RELIEF FOR LATE JULY STANDARDS. NOT AS HOT
TODAY WITH HIGHS IN THE MID 80S (70S MOUNTAINS) AND WAKE UP
TEMPERATURES EARLIER THIS MORNING IN THE 50S/60S. REGIONAL SOUNDINGS
CONTINUE TO INDICATE AMPLE DRY AIR ALOFT WITH BROAD CANADIAN HIGH
PRESSURE ANCHORED OVER EASTERN ONTARIO AND WESTERN NEW YORK. PWATS
RANGE FROM 0.7 INCHES AT KPBZ TO 1.2 INCHES AT KIAD AND 1.3
INCHES AT KRNK. WITH THAT SAID, JUST ENOUGH MOISTURE EXISTS IN
THE PROFILE FOR FOR SOME LOW CLOUDS EAST OF THE BLUE RIDGE AND
PATCHY FOG FURTHER WEST OF THE I-95 CORRIDOR HEADING INTO
TONIGHT. LIGHT ONSHORE EAST TO NORTHEAST FLOW WILL HELP FURTHER
CONFIDENCE FOR AREA OF LOW CLOUDS EAST OF THE BLUE RIDGE LATE
TONIGHT INTO EARLY WEDNESDAY MORNING.
OUTSIDE OF THE LOW CLOUDS AND FOG POTENTIAL CONDITIONS WILL REMAIN
DRY. SOME HI-RES MODELS HAVE A FEW SPRINKLES UP ACROSS NORTHEAST MD
AND THE WESTERN SHORE OF THE BAY. CONFIDENCE IN THIS IS LOW GIVEN
THE AMOUNTS OF RESIDUAL FORCING (SURFACE CONVERGENCE) WHICH WAS
NOTED EARLIER IN THE DAY BETWEEN THE SHIFTING RIDGE TO THE NORTH AND
SEABREEZE OFF THE ATLANTIC.
THE REPRIEVE IN THE OPPRESSIVE HUMIDITY WILL CONTINUE WITH DEWPOINTS
ONCE AGAIN IN THE UPPER 50S AND LOW 60S. THE COMBINATION OF THE
LOWER HUMIDITY AND LOWS IN THE LOW TO MID 60S (50S MOUNTAINS/DEEPER
VALLEYS) WILL ALLOW FOR ANOTHER GREAT NIGHT TO GIVE THE AIR
CONDITIONERS A BREAK. THIS WILL BE MUCH NEEDED ESPECIALLY WITH HIGH
HEAT AND HUMIDITY RETURNING LATER THIS WEEK.
SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/
THE CANADIAN HIGH SLIDES OFFSHORE THROUGH THE MIDDLE OF THE
WEEK. DRY CONDITIONS PERSIST OVER THE MID-ATLANTIC AS WINDS TURN
SOUTHEAST THEN SOUTH. TEMPERATURES STEADILY INCREASE EACH DAY,
REACHING THE UPPER 80S WEDNESDAY AND LOW 90S ON THURSDAY.
HUMIDITY SLOWLY STARTS TO INCREASE DURING THIS TIME, THOUGH
STILL WELL BELOW WHAT WE EXPERIENCED FOR THE PAST SEVERAL WEEKS.
OVERNIGHT LOWS WILL BE IN THE 60S, THOUGH IT WILL TURN
NOTICEABLY MUGGIER THURSDAY NIGHT AS TEMPERATURES SETTLE INTO
THE 70S ON A WARM SOUTHERLY BREEZE.
LONG TERM /FRIDAY THROUGH TUESDAY/
UPPER-LEVEL RIDGE WILL START BREAKING DOWN FRI ALLOWING FOR
INCREASING CHANCES OF AFTERNOON AND EVENING THUNDERSTORMS.
UPPER-LEVEL PERTURBATIONS ROUNDING THE TOP OF THE RIDGE WILL
WEAKEN THE RIDGE FURTHER ON SATURDAY AND BRING A MARKED
INCREASE OF CONVECTION SAT INTO SUN. THE MOST ACTIVE DAY LOOKS
TO BE SUNDAY AS A WEAK BACKDOOR FRONT MAKES IT INTO NORTHEAST
MARYLAND. GIVEN THE EXTREME HEAT AND INSTABILITY, SEVERE
THUNDERSTORMS ARE POSSIBLE. THE FRONT LINGERS ACROSS THE AREA
INTO EARLY NEXT WEEK KEEPING THE RISK OF DAILY SHOWERS AND
THUNDERSTORMS. HOT AND HUMID FRI AND SAT WITH HEAT INDICES AT OR
ABOVE ADVISORY CRITERIA.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS LOOK TO CONTINUE THROUGH THURSDAY AS CANADIAN HIGH
PRESSURE TO THE NORTH SLIDES OFFSHORE. A BRIEF PERIOD OF LOW
CIGS CANNOT BE RULED OUT LATE TONIGHT INTO EARLY WEDNESDAY
MORNING FOR TERMINALS EAST OF THE BLUE RIDGE DUE TO THE
INFLUENCE OF LIGHT EASTERLY ONSHORE FLOW. THIS WILL LIKELY BE
THE CASE WEDNESDAY NIGHT INTO THURSDAY MORNING AS WELL WITH
WINDS SLOWLY TRANSITIONING BACK TO THE SOUTH AND SOUTHEAST.
PATCHY FOG IS ALSO POSSIBLE AT CHO/MRB OVER THE NEXT 2 MORNINGS
GIVEN THE PROXIMITY TO NEARBY WATERWAYS. WINDS WILL REMAIN LIGHT
OUT OF THE EAST TONIGHT BEFORE SWITCHING TO THE SOUTHEAST
WEDNESDAY AND SOUTH THURSDAY AT LESS THAN 10 KTS.
ISOLATED SHOWERS AND THUNDERSTORMS RETURN FRIDAY AS THE RIDGE OF
HIGH PRESSURE BUCKLES. THIS WILL LEAD TO SOME TEMPORARY REDUCTIONS
DURING THE AFTERNOON AND EVENING HOURS. HIGHER CONFIDENCE FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXISTS THIS
WEEKEND AS SEVERAL WAVES OF ENERGY AND A FRONT PASS THROUGH THE
REGION. ADDITIONAL RESTRICTIONS ARE POSSIBLE ONCE AGAIN DURING
THE AFTERNOON AND EVENING HOURS.
MARINE
FAVORABLE MARINE CONDITIONS ARE LIKELY TO PERSISTS THROUGH THURSDAY
MORNING AS CANADIAN HIGH PRESSURE TO THE NORTH OF THE WATERS MOVES
OFFSHORE. WINDS WILL TURN FROM EAST TO THE SOUTHEAST LATE TONIGHT
INTO WEDNESDAY. SOUTHERLY WINDS AND THE POTENTIAL FOR SOUTHERLY
CHANNELING RETURNS THURSDAY EVENING INTO THURSDAY NIGHT OVER THE
MIDDLE/LOWER PORTION OF THE CHESAPEAKE BAY. THERE ALSO REMAINS HINTS
OF BRIEF BAY/RIVER BREEZE ENHANCEMENTS DURING THE LATE AFTERNOON TO
EARLY EVENING HOURS EACH OF THE NEXT COUPLE OF DAYS, BUT THESE
SHOULD BE ABLE TO BE HANDLED WITH MWSS, IF NECESSARY.
SCA CONDITIONS ARE POSSIBLE THURSDAY NIGHT THROUGH FRIDAY
NIGHT, PARTICULARLY AT NIGHT DUE TO CHANNELING. SCATTERED
THUNDERSTORMS EXPECTED SATURDAY.
TIDES/COASTAL FLOODING
AS WINDS TURN MORE SOUTHERLY TONIGHT, EXPECT WATER LEVEL RISES ON
THE CHESAPEAKE BAY WHICH MAY RESULT IN MINOR COASTAL FLOODING AT
ANNAPOLIS. AS SOUTHERLY WINDS STRENGTHEN OVER THE WEEKEND, EXPECT
THE RISK OF MINOR COASTAL FLOODING TO CONTINUE THROUGH THE WEEKEND.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
SYNOPSIS...EST
NEAR TERM...EST
SHORT TERM...DHOF/KRR
LONG TERM...LFR
AVIATION...LFR/DHOF/EST
MARINE...LFR/DHOF/EST
TIDES/COASTAL FLOODING...LFR/KRR
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