660
FXUS61 KLWX 130729
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
329 AM EDT THU AUG 13 2026
WHAT HAS CHANGED
A BIT HOTTER TODAY WITH A SPOTTY SHOWER OR T-STORM. MORE T-STORMS
FRIDAY AS A FRONT PUSHES THROUGH THE REGION. LOWER HUMIDITY SATURDAY
WITH A BRIEF LULL BEFORE MORE STORM CHANCES SUNDAY AND MONDAY.
KEY MESSAGES
- 1) LOW STORM CHANCES CONTINUE TODAY WITH HIGHER HUMIDITY AND HOTTER
TEMPERATURES. MORE STORMS FRIDAY AS THE FRONT SAGS SOUTH.
- 2) SHOWERS AND THUNDERSTORMS POSSIBLE BETWEEN SUNDAY AND
MONDAY BEFORE BECOMING DRIER INTO EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...LOW STORM CHANCES CONTINUE TODAY WITH HIGHER HUMIDITY
AND HOTTER TEMPERATURES. MORE STORMS FRIDAY AS THE FRONT SAGS SOUTH.
IT'S ANOTHER MOSTLY DRY DAY AHEAD WITH JUST A FEW SPOTTY SHOWERS AND
T-STORMS ACROSS THE REGION. STILL MONITORING THE UPPER LEVEL RIDGE
NEARBY OVER THE CENTRAL AND SOUTHEASTERN U.S ALONG WITH A NEARBY
STALLED FRONT DRAPED FROM THE VA TIDEWATER WESTWARD INTO THE TN/OHIO
RIVER VALLEYS. PIECES OF ENERGY WILL CONTINUE TO TRAVERSE THIS
BOUNDARY WITHIN WEST TO NORTHWEST FLOW TODAY THROUGH FRIDAY.
CONFIDENCE IN TIMING AND THUNDERSTORM COVERAGE IS LOW FOR TODAY
GIVEN THE HEIGHTENED RIDGE WITH INCREASING CHANCES FRIDAY AS THE
RIDGE FLATTENS AND FRONT MOVES THROUGH.
AS FOR TODAY, EXPECT ANY RESIDUAL SHOWERS EARLY THIS MORNING OVER
NORTHEAST MD, SOUTHERN MD, AND CENTRAL VA TO QUICKLY END AS A WEAK
UPPER LEVEL TROUGH PUSHES EAST PRIOR TO 8Z/4AM. ADDITIONAL SPOTTY
SHOWERS AND THUNDERSTORMS MAY DOT THE AREA LATER THIS AFTERNOON WITH
A FOCUS OVER THE ALLEGHENIES (DUE TO TERRAIN CIRCULATIONS) AND
ACROSS CENTRAL VA/SHENANDOAH VALLEY WHERE THE FRONT RESIDES. THE
FRONT WILL GRADUALLY LIFT BACK TOWARD THE NORTH LATE TONIGHT INTO
FRIDAY WITH ANOTHER WAVE OF LOW PRESSURE SET TO PUSH THROUGH. THIS
WILL LEAD TO INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS
THE REGION WITH A FOCUS, ESPECIALLY ALONG AND SOUTH OF I-66/US-50.
THUNDERSTORM ACTIVITY WILL LIKELY OCCUR DURING THE PEAK HEATING
PERIOD WITH LOCALLY DAMAGING WINDS, FREQUENT LIGHTNING, AND ISOLATED
INSTANCES OF FLASH FLOODING AS THE PRIMARY CONCERNS. SPC CONTINUES
TO HIGHLIGHT AREAS ALONG AND SOUTH OF US-33 IN VA WITH A MARGINAL
RISK (LEVEL 1 OUT OF 5) FOR SEVERE WEATHER. THIS ALIGNS WITH MACHINE
LEARNING/ AI GUIDANCE WHICH SUGGESTS 5 TO 15 PERCENT PROBS FOR
SEVERE WEATHER FRIDAY AFTERNOON AND EVENING. A LOT OF THIS WILL BE
DEPENDENT UPON CLOUD COVER AND ANY INTERACTION FROM POTENTIAL MCSS
DIVING ACROSS THE CENTRAL AND LOWER OHIO RIVER VALLEY AND INTO FAR
SOUTHERN WV/SOUTHWEST VA. SOME GUIDANCE REMAINS AGGRESSIVE LIKE THE
NAMNEST WHILE THE HRRR, ARW, AND NSSL REMAIN MORE REASONABLE WITH
COVERAGE/MAGNITUDE. NO WASHOUTS ARE EXPECTED ALTHOUGH CHANCES WILL
INCREASE DURING THE PEAK HEATING PERIOD, ESPECIALLY SOUTH AND WEST
OF THE I-95 METRO AREAS.
HIGH PRESSURE BUILDS FROM THE NORTH FRIDAY NIGHT SHUNTING THE FRONT
FURTHER SOUTH OF THE REGION. THIS WILL ALLOW FOR DRIER CONDITIONS TO
PREVAIL ALONG WITH A BRIEF BREAK IN THE HUMIDITY. HIGHS TODAY WILL
PUSH INTO THE MID 80S AND LOW 90S WITH HEAT INDEX VALUES IN THE MID
TO UPPER 90S EAST OF THE ALLEGHENIES. OVERNIGHT LOWS WILL FALL BACK
INTO THE UPPER 60S AND LOW 70S WITH HIGHS FRIDAY INTO THE 80S.
AMPLE HIGH PRESSURE BUILDS TO THE NORTH OF THE REGION ON SATURDAY
SHUNTING THE FRONT INTO THE CAROLINAS. AN ONSHORE COMPONENT TO THE
WIND COULD KEEP SOME ADDITIONAL CLOUD COVER AROUND WITH PARTLY
CLOUDY SKIES EXPECTED. HUMIDITY WILL BRIEFLY DROP WITH HIGHS IN THE
LOW TO MID 80S (UPPER 80S IN THE CITY CENTERS AND 70S OVER THE
MOUNTAINS).
KEY MESSAGE 2... SHOWERS AND THUNDERSTORMS POSSIBLE BETWEEN SUNDAY
AND MONDAY BEFORE BECOMING DRIER INTO EARLY NEXT WEEK.
BEGINNING SUNDAY, AN UPPER-LEVEL PERTURBATION FORMS OVER THE
CANADIAN ROCKIES AND TRACKS EASTWARD, WITH A STEMMING FRONTAL
BOUNDARY TRACKING ACROSS THE EAST COAST LATE SUNDAY AND INTO MONDAY.
THIS BOUNDARY WILL LIKELY BRING CHANCES FOR SCATTERED SHOWERS AND
THUNDERSTORMS HERE IN THE MID-ATLANTIC, ALTHOUGH MODEL GUIDANCE HAS
BEEN SOMEWHAT MARGINAL ON THE SEVERE POTENTIAL FOR THIS EVENT. AS OF
THE 18Z ENSEMBLE RUNS, SEVERAL OUTPUTS HAVE THE HIGHEST LIKELIHOOD
FOR SEVERE WEATHER JUST SOUTH OF THE AREA TOWARDS SOUTHERN VA AND
THE CAROLINAS, WHILE THE GFS ENSEMBLE RUNS STILL HAVE A 15%-30%
PROBABILITY FOR SEVERE WEATHER CENTERED WITHIN THE REGION. SHOULD
ANY THUNDERSTORMS BECOME SEVERE, THE MOST LIKELY HAZARDS WILL LIKELY
BE GUSTY WINDS AS WELL AS LOCALLY HEAVY RAINFALL. AS DROUGHT
CONDITIONS CONTINUE TO IMPROVE WITHIN THE REGION, FLOODING POTENTIAL
BECOMES MORE OF A CONCERN WITH ANY HEAVY RAINFALL-PRODUCING
THUNDERSTORMS THAT MATERIALIZE.
OTHERWISE, TEMPERATURES REMAIN NEAR-NORMAL FOR MID-AUGUST, WITH
HUMID CONDITIONS AS WELL AS TEMPERATURES RANGING IN THE 80S AND
LOWER-90S AT TIMES NEAR THE METROS. HIGH PRESSURE MOVES IN AROUND
THE OHIO RIVER VALLEY, SHIFTING SURFACE WINDS COMING OUT OF THE NW.
ONCE THAT FRONTAL BOUNDARY PASSES OFFSHORE BY TUESDAY, IT COULD
BRING IN SOME MUCH NEEDED RELIEF TO THE HUMID CONDITIONS EXPECTED
THIS WEEKEND.
AVIATION /07Z THURSDAY THROUGH MONDAY/
PREVAILING VFR CONDITIONS WILL CONTINUE TODAY AS THE FRONTAL
BOUNDARY SITS ALONG AND SOUTH OF A LINE FROM KSHD/KCHO OVER TO KRIC.
THIS WILL BE THE AREA OF CONCERN FOR A SPOTTY SHOWER OR T-STORMS
THIS AFTERNOON MAINLY DURING THE PEAK HEATING PERIOD BETWEEN 19-
00Z/3-8PM. DID ADD A PROB30 IN AT CHO FOR THIS THREAT ALTHOUGH
CONFIDENCE IS LOW GIVEN THE HIGHER HEIGHTS OVERHEAD FROM THE UPPER
LEVEL RIDGE ALOFT. WINDS WILL REMAIN LIGHT OUT OF THE WEST AND
NORTHWEST AT LESS THAN 15 KTS. BETTER THUNDERSTORM COVERAGE IS
EXPECTED FRIDAY AS THE FRONT LIFTS BACK INTO THE REGION. THIS COULD
LEAD TO TEMPORARY REDUCTIONS DURING THE AFTERNOON AND EVENING
PERIOD. SEVERE WEATHER WILL ALSO BE A CONCERN FOR AREAS MAINLY SOUTH
OF THE CORRIDOR TERMINALS. DAMAGING WINDS WOULD BE THE PRIMARY
THREAT WITH STORMS ALONG WITH FREQUENT LIGHTNING AND LOCALLY HEAVY
RAINFALL LEADING TO VSBY REDUCTIONS. WINDS WILL REMAIN OUT OF THE
NORTH AND NORTHWEST AT LESS THAN 15 KTS.
VFR CONDITIONS ARE FORECAST FOR BOTH SATURDAY AND SUNDAY. WINDS WILL
BE LIGHT OUT OF THE NORTH TO NORTHEAST ON SATURDAY, BEFORE TURNING
OUT OF THE SOUTH ON SUNDAY. A FEW AFTERNOON SHOWERS OR THUNDERSTORMS
COULD BE POSSIBLE ON SUNDAY, POTENTIALLY LEADING TO BRIEF
RESTRICTIONS AT THE TERMINALS AS A COLD FRONT ENTERS THE REGION.
THESE CONDITIONS COULD BE INTERMITTENT THROUGH MONDAY AS THE FRONT
PASSES THROUGH. SOUTHEAST WINDS SHIFT NORTHWEST MONDAY EVENING IN
THE WAKE OF THE FRONT.
MARINE
SUB-SCA LEVEL WINDS ARE EXPECTED TODAY WITH AN ISOLATED SHOWER OR T-
STORM OVER THE WATERS. OVERALL NO MARINE HAZARDS TODAY WITH THE RISK
OF SPECIAL MARINE WARNINGS FRIDAY AFTERNOON AS SCATTERED TO NUMEROUS
STORM CHANCES ARE LOOKING LIKELY AHEAD OF A CROSSING COLD FRONTAL
BOUNDARY. ANY STORM WILL BE CAPABLE OF GUSTY WINDS AND FREQUENT
LIGHTNING. THIS FRONT DROPS TOWARD THE CAROLINAS ON SATURDAY AS HIGH
PRESSURE BUILDS OVER THE NORTHEASTERN U.S. THE RESULTING WINDS WILL
MAINLY BE OUT OF THE EAST TO NORTHEAST.GUSTS WILL MOSTLY BE IN THE 5
TO 10 KNOT RANGE TODAY THROUGH FRIDAY, WHILE PUSHING UP TO 15 KNOTS
AT TIMES WHEN CHANNELING OCCURS (MAINLY OVER THE OPEN WATERS)
SCAS WILL LIKELY BE NEEDED BY SUNDAY AFTERNOON AS A COLD FRONT
TRACKS THROUGH THE REGION. BETWEEN SUNDAY & MONDAY, GUSTY SHOWERS
AND THUNDERSTORMS ARE POSSIBLE OVER THE WATERS. WINDS DIMINISH ONCE
THE FRONT PASSES THROUGH LATE MONDAY. SOUTHEAST WINDS SHIFT
NORTHWEST BY MONDAY EVENING IN THE WAKE OF THE FRONT.
TIDES/COASTAL FLOODING
WATER LEVELS WILL SLOWLY ELEVATE IN THE NEXT COUPLE OF DAYS.
THIS BRINGS A MORE SENSITIVE LOCATION LIKE ANNAPOLIS INTO ACTION
STAGE FOR THE THURSDAY MORNING HIGH TIDE. HOWEVER, THERE REMAINS NO
DISCERNIBLE THREAT FOR COASTAL FLOODING THIS WEEK.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
DISCUSSION...EST/SRT/KVH
AVIATION...EST/SRT
MARINE...EST/SRT
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