461
FXUS61 KLWX 131930
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
330 PM EDT WED MAY 13 2026
WHAT HAS CHANGED
GREATEST CHANCE OF SEVERE WX THIS AFTERNOON/EVENING IN VICINITY
OF WESTERN MARYLAND.
KEY MESSAGES
1) GUSTY THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING.
2) ABOVE AVERAGE TEMPERATURES EXPECTED BEGINNING THIS
WEEKEND ALONG WITH DAILY SHOWER AND THUNDERSTORM CHANCES.
DISCUSSION
KEY MESSAGE 1...GUSTY THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON
AND EVENING.
CURRENTLY SHOWERS ARE LOCATED ACROSS THE BLUE RIDGE WELL AHEAD
OF THE SURFACE COLD FRONT WHICH IS BACK NEAR PITTSBURGH. THIS
LEAD DISTURBANCE WILL CROSS THE AREA THIS AFTERNOON, QUICKLY
INCREASING CLOUD COVER. WHILE AN EMBEDDED RUMBLE OF THUNDER IS
POSSIBLE, INSTABILITY WILL LARGELY BE LACKING WITH THIS FIRST
ROUND. COMBINED WITH RESIDUAL DRY AIR IN PLACE AND SHOWERS
OUTRUNNING THE FORCING, IT'S POSSIBLE THEY GREATLY DIMINISH BY
THE TIME THEY REACH THE I-95 CORRIDOR LATER THIS AFTERNOON.
A SECOND ROUND OF SHOWERS AND T-STORMSHAS FORECAST ACROSS
WESTERN PA BACK INTO EASTERN OHIO AHEAD OF THE COLD FRONT.
THERE WILL BE ONLY A FEW HOURS FOR THE ATMOSPHERE TO RECOVER
FROM THE PREVIOUS SHOWERS, SO INSTABILITY WILL LIKELY BE
LIMITED. HOWEVER, FORCING, MOISTURE, AND SHEAR WILL BE PRESENT,
SO SOME STRONGER STORMS COULD STILL DEVELOP AS THE AXIS MOVES
EASTWARD ACROSS THE APPALACHIANS DURING THE LATE AFTERNOON OR
EARLY EVENING. GREATEST THREAT FOR SVR WX IS IN ANY ORGANIZED
SEGMENTS WITH THE GREATEST PROBABILITY OF OCCURRENCE IN WESTERN
MARYLAND. STRONG OUTFLOW WINDS WILL BE THE MAIN THREAT WITH ANY
STRONGER STORMS/LINEAR SEGMENTS. WITH SUNSET AND WEAKER
ANTECEDENT INSTABILITY EAST OF I-81, THE SEVERE THREAT GREATLY
DIMINISHES FURTHER EAST.
SOME RESIDUAL SHOWERS COULD LINGER UNTIL THE COLD FRONT PASSES
LATE, AND UPSLOPE RAIN SHOWERS WILL START IN THE ALLEGHENY
MOUNTAINS. IF ANY CLEARING CAN OCCUR BETWEEN THE MAIN RAIN AND
THE WIND SHIFT TO NW, SOME FOG MAY DEVELOP.
GULL PRESSURE WILL PIVOT OVER THE NORTHERN MID-ATLANTIC ON
THU WHILE SURFACE LOW PRESSURE REDEVELOPS OVER NEW ENGLAND.
THIS WILL RESULT IN GUSTY NW WINDS AND PLENTIFUL STRATOCUMULUS.
RAIN SHOWERS APPEAR MOSTLY LIMITED TO UPSLOPE AREAS IN THE
ALLEGHENIES, BUT CAN'T TOTALLY RULE OUT AN ISOLATED SHOWER OR
SPRINKLE ELSEWHERE. TEMPS WILL BE COOLER BENEATH THE TROUGH AS
WELL, WITH MOST LOWER ELEVATIONS IN THE 60S. THERE COULD EVEN BE
A FEW WET SNOWFLAKES MIXED IN ON THE HIGH PEAKS ABOVE 4000 FEET
THU MORNING.
KEY MESSAGE 2...ABOVE AVERAGE TEMPERATURES EXPECTED BEGINNING THIS
WEEKEND ALONG WITH DAILY SHOWER AND THUNDERSTORM CHANCES.
SURFACE HIGH PRESSURE SHIFTS OFFSHORE SATURDAY THROUGH EARLY NEXT
WEEK WITH RETURN FLOW USHERING IN WARMER TEMPERATURES. ALOFT, UPPER
LEVEL RIDGING SLOWLY BUILDS OVER THE EASTERN CONUS THROUGH MID WEEK.
ON SATURDAY, HIGH TEMPERATURES WILL BE IN THE LOW TO MID 80S FOR
MOST WITH HIGHER ELEVATIONS STAYING IN THE MID 70S. TEMPERATURES
GRADUALLY WARM EACH DAY WITH HIGHS SOARING INTO THE MID 90S FOR MOST
ON TUESDAY.
IN ADDITION TO HIGH PRESSURE SHIFTING OFFSHORE, A COLD FRONT SLOWLY
APPROACHES THE FORECAST AREA FROM THE NORTHWEST. THIS WILL YIELD
DAILY SHOWER AND THUNDERSTORM CHANCES, PRIMARILY IN THE
ALLEGHENIES.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
S'LY GUSTS TO 25 KTS CONTINUE. THERE MAY BE MULTIPLE ROUNDS OF
SHOWERS AND EMBEDDED TSTORMS, ONE DURING THE AFTERNOON TO EARLY
EVENING, AND THE SECOND FOLLOWING A FEW HOURS LATER DURING THE
EVENING. INSTABILITY IS FAIRLY WEAK WITH THE FIRST ROUND, SO
HAVE LEFT OUT THUNDER MENTIONS, BUT DID TRY TO SHOW THE BREAK
WITH THE SECOND ROUND. THE SECOND ROUND WILL LIKELY BE WEAKENING
WITH EASTWARD EXTENT, SO ONLY HAVE PROB30 TSRA AT MRB, CHO, AND
IAD. ANY STRONGER STORMS COULD CONTAIN GUSTY OUTFLOW,
ESPECIALLY AT MRB. WINDS WILL LIKELY SHIFT TO THE WEST AFTER THE
SECOND ROUND OF SHOWERS BUT BE LIGHT OR EVEN CALM IN SPOTS,
WHICH COULD LEAD TO FOG DEVELOPMENT SHOULD ANY CLEARING TAKE
PLACE. HOWEVER, SOME GUIDANCE SUGGEST MVFR TO IFR CEILINGS WILL
DEVELOP, ESPECIALLY OVER THE METRO TERMINALS NEAR AND JUST AFTER
SHOWERS END. A WIND SHIFT TO NORTHWEST LATE AT NIGHT SHOULD
ASSIST IN IMPROVING CONDITIONS.
AN UPPER LEVEL LOW WILL BE NEARBY THU BEFORE MOVING EAST
FRI. THIS WILL LIKELY RESULT IN STRATOCUMULUS CEILINGS, WITH A
WORST CASE BEING MVFR. NW'LY WINDS WILL ALSO GUST 20 TO 25 KT
BOTH DAYS.
SW WINDS ON SAW BLOW 5 TO 10 KNOTS WITH GUSTS UP TO 15 KNOTS
EXPECTED IN THE MORNING. WINDS BECOME LIGHT OVERNIGHT BEFORE
SHIFTING TO W'LY SUN MORNING. WINDS REMAIN LIGHT ON SUN,
BLOWING 5 TO 10 KNOTS. PRIMARILY VFR CONDITIONS ARE EXPECTED
BOTH DAYS AS PRECIP CHANCES REMAIN LOW (30% OR LESS).
MARINE
SCAS FOR S'LY FLOW WITH GUSTS UP TO 30 KTS REMAIN IN EFFECT. A
FEW T-STORMS COULD REACH THE WATERS THIS EVENING, BUT AT THIS
TIME THE THREAT FOR SMWS APPEARS LOW AS ACTIVITY SHOULD BE
WEAKENING. THE SCA WAS EXTENDED THROUGH THE EVENING ALONG THE
BAY. WINDS WILL BE LIGHTER FOR A TIME BEFORE THE COLD FRONT
BRINGS A SHIFT TO THE NW EARLY THU MORNING. THE LENGTH OF THIS
GAP IS A BIT UNCERTAIN, BUT ADVISORIES WILL DEFINITELY BE NEEDED
AFTER SUNRISE THU WITH GUSTS TO 25 KT. GUSTY NW WINDS AND
ADVISORIES WILL CONTINUE INTO FRI FOR SOME IF NOT ALL WATERS.
WINDS FALL BELOW SCA CRITERIA BY FRI EVENING.
WINDS AROUND 15 KNOTS OUT OF THE SOUTHWEST ON SATURDAY BEFORE
BECOMING LIGHT OVERNIGHT. WEST WINDS BLOW 5 TO 10 KNOTS OVER THE
WATERS ON SUNDAY. NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED EITHER
DAY.
TIDES/COASTAL FLOODING
WATER LEVELS ARE GRADUALLY INCREASING IN GUSTY S'LY FLOW AHEAD
OF A LOW PRESSURE SYSTEM. FOR THE MOST PART, PEAKS IN ACTION
STAGE ARE EXPECTED, WITH THE HIGHEST TIDE OCCURRING TONIGHT. THE
STEVENS ENSEMBLE SHOWS THE POTENTIAL FOR MINOR TIDAL FLOODING
AT ANNAPOLIS, BUT OTHER GUIDANCE IS JUST BELOW. EXPECT ANOMALIES
TO FALL THEREAFTER AS WINDS SHIFT TO NW'LY.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY UNTIL 1 AM EDT THURSDAY FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT THURSDAY FOR ANZ530>534-
537>543.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ535-
536.
DISCUSSION...ADS/AVS/CPB
AVIATION...ADS/AVS/CPB
MARINE...ADS/AVS/CPB
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