273
FXUS61 KLWX 140034
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
834 PM EDT SUN SEP 13 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGE 1 FOR LATEST OBSERVATIONS AND TRENDS.
KEY MESSAGES
- 1) SOME LINGERING SHOWERS THROUGH THIS EVENING BEFORE TURNING
COOLER WITH LESS HUMIDITY ON MONDAY AND TUESDAY.
- 2) INCREASING PRECIPITATION CHANCES LATER IN THE WEEK WITH AN
INCOMING COLD FRONT.
DISCUSSION
KEY MESSAGE 1...SOME LINGERING SHOWERS THROUGH THIS EVENING
BEFORE TURNING COOLER WITH LESS HUMIDITY ON MONDAY AND TUESDAY.
AS OF 830 PM, RADAR IMAGERY SHOWS ONE SHOWER ACROSS SOUTHERN
PRINCE WILLIAM COUNTY, AND THEN ADDITIONAL SHOWERS AND STORMS
ACROSS SOUTHWESTERN PA AND NORTHERN WV. THESE SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO GRADUALLY DECAY AS THEY MOVE INTO
THE AREA FROM THE NORTHWEST OVER THE NEXT FEW HOURS. LOCATIONS
ALONG THE ALLEGHENY FRONT OR IN THE POTOMAC HIGHLANDS MAY
EXPERIENCE A BRIEF SHOWER OR RUMBLE OF THUNDER OVER THE NEXT FEW
HOURS. THE SHOWERS ARE EXPECTED TO COMPLETELY DISSIPATE BEFORE
REACHING I-81. PREVIOUS DISCUSSION FOLLOWS...
HEADING INTO TONIGHT, AN APPROACHING COLD FRONT FROM THE GREAT
LAKES MAY INDUCE ADDITIONAL SHOWERS ALONG AND WEST OF THE
ALLEGHENY FRONT AS WEAKENING STORMS APPROACH FROM THE OHIO
VALLEY. THIS THREAT SHOULD END AROUND OR SHORTLY AFTER MIDNIGHT.
OTHERWISE, THIS IS LARGELY A DRIER FRONTAL PASSAGE WHICH WILL
ALSO LEAD TO COOL TEMPERATURES AND LOWER HUMIDITY TO START OFF
THE WORK WEEK.
GRADIENTS ON MONDAY ARE RATHER TIGHT FOR MID-SEPTEMBER AS A
BROAD 1024-MB SURFACE HIGH APPROACHES FROM THE GREAT LAKES. THIS
WILL FAVOR A BREEZY NORTHWESTERLY WIND FOR MONDAY, WITH GUSTS
UP TO 20 TO 25 MPH AT TIMES. FORECAST HIGHS ARE IN THE MID 70S
TO LOW 80S (5 TO 15 DEGREES COOLER FOR MOUNTAIN LOCALES).
AS THE SEASONABLY STRONG DOME OF HIGH PRESSURE SETTLES OVER THE
NORTHEASTERN U.S. MONDAY NIGHT, LOW TEMPERATURES PLUNGE INTO
THE UPPER 40S TO 50S. THE AUTUMNAL FEEL TO THE AIR LINGERS INTO
TUESDAY BEFORE AN EVENTUAL WARM UP BY MID-WEEK. PLENTY OF
SUNSHINE CAN BE EXPECTED EACH DAY, BUT WITH DECREASING WINDS ON
TUESDAY WITH THE RIDGE ALONG THE EASTERN SEABOARD. THIS ALL
COMES WITH DEW POINTS IN THE UPPER 40S TO MID 50S WHICH IS
CERTAINLY A CHANGE FROM RECENT DAYS.
KEY MESSAGE 2...INCREASING PRECIPITATION CHANCES LATER IN THE WEEK
WITH AN INCOMING COLD FRONT.
UPPER-LEVEL RIDGING COULD CONTINUE INTO WEDNESDAY, THEN BEGIN
TO BREAK DOWN AS A TROUGH FORMS OVER THE HUDSON BAY. A STEMMING
COLD FRONT TRACKS EAST OVER THE MID-ATLANTIC DURING THE LATER
HALF OF THE WEEK, BRINGING INCREASING HUMIDITY AS WELL AS SHOWER
& THUNDERSTORM CHANCES. THERE IS STILL SOME UNCERTAINTY IN THE
TIMING OF ANY PRECIPITATION, BUT GENERALLY THERE SHOULD BE
INCREASING CLOUD COVER BY THURSDAY WITH A POTENTIAL FOR SHOWERS
& THUNDERSTORMS BETWEEN THURSDAY AND THROUGHOUT THE WEEKEND AS
THE FRONT MOVES THROUGH. SEVERE PROBABILITIES CONTINUE TO LOOK
MINIMAL FOR THIS PERIOD.
TEMPERATURES RISE BACK INTO THE MID-TO-UPPER 80S ACROSS THE REGION
THROUGH FRIDAY, THEN DROP AGAIN IN THE WAKE OF THE FRONT HEADING
INTO THE WEEKEND.
AVIATION /00Z MONDAY THROUGH FRIDAY/
HAVE REMOVED THUNDER FROM THE TAFS GIVEN INCREASINGLY SHALLOW
CONVECTION NOW PRODUCING MINIMAL LIGHTNING THANKS TO INCREASING
SUBSIDENCE ALOFT. OTHERWISE, VFR IS EXPECTED THROUGH MONDAY
NIGHT. WINDS TURN N/NW MONDAY AND GUST 20-25 KTS.
VFR CONDITIONS AND LIGHTER WINDS THEN CONTINUE MONDAY NIGHT THROUGH
TUESDAY AS HIGH PRESSURE BUILDS OVER THE REGION. WINDS SHIFT TO
THE EAST AND SOUTHEAST TUESDAY INTO TUESDAY NIGHT.
PREVAILING VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THURSDAY
AND FRIDAY. DURING THE AFTERNOON & EVENING HOURS THROUGHOUT THIS
PERIOD, A PASSING COLD FRONT COULD BRING TEMPORARY LOW CIGS AT
TERMINALS AS A FEW SHOWERS AND/OR THUNDERSTORMS MOVE THROUGH THE
REGION. SOUTHERLY WINDS SHIFT NORTHEASTERLY ON FRIDAY.
MARINE
A POP UP SHOWER OR STORM CAN'T BE RULED OUT THROUGH EARLY THIS
EVENING. A COLD FRONT ARRIVING EARLY MONDAY IS FORECAST TO
YIELD INCREASING NORTHWESTERLY WINDS WITH GUSTS UP TO 20 TO 25
KNOTS. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FROM EARLY MONDAY
MORNING INTO MONDAY NIGHT. MULTIPLE WIND SHIFTS TAKE PLACE ON
TUESDAY AS HIGH PRESSURE PASSES BY TO THE NORTH. HOWEVER, GUSTS
DROP OFF BACK INTO THE 5 TO 10 KNOT RANGE, GENERALLY OUT OF THE
EAST TO SOUTHEAST.
WINDS STAY BELOW SCA THRESHOLDS THROUGH FRIDAY. SOUTHERLY WINDS
SHIFT NORTHERLY BY FRIDAY AFTERNOON IN THE WAKE OF A COLD FRONT,
WHICH COULD BRING A FEW SHOWERS AND/OR THUNDERSTORMS OVER THE WATERS
BETWEEN THURSDAY & FRIDAY EVENING.
TIDES/COASTAL FLOODING
TIDE LEVELS WILL REMAIN ELEVATED TONIGHT, WITH ANNAPOLIS,
ALEXANDRIA, AND HAVRE DE GRACE POSSIBLY APPROACHING MINOR.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM EDT MONDAY FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM EDT MONDAY FOR
ANZ530>533-535-536-538>542.
SMALL CRAFT ADVISORY FROM 4 AM MONDAY TO 7 AM EDT TUESDAY FOR
ANZ534-537-543.
DISCUSSION...LFR/BRO/DHOF/KJP
AVIATION...LFR/BRO/DHOF
MARINE...LFR/BRO/DHOF
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