491
FXUS61 KLWX 201939
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
339 PM EDT MON JUL 20 2026
WHAT HAS CHANGED
ENHANCED SEVERE WEATHER RISK FOR TUE WAS EXPANDED TO COVER MOST
OF THE FORECAST AREA.
KEY MESSAGES
- STRONG TO SEVERE THUNDERSTORMS ARE LIKELY TUESDAY, WITH
SOME THUNDERSTORM RISK LINGERING INTO WEDNESDAY.
- COOLER THAN AVERAGE TEMPERATURES ANTICIPATED BEGINNING
THURSDAY THROUGH THE END OF THE WEEK.
DISCUSSION
KEY MESSAGE 1...STRONG TO SEVERE THUNDERSTORMS ARE LIKELY TUESDAY, WITH
SOME THUNDERSTORM RISK LINGERING INTO WEDNESDAY.
KEY MESSAGE 1 DESCRIPTION...
MOISTURE IS EXPECTED TO RETURN IN EARNEST TONIGHT IN
STRENGTHENING SRLY FLOW. ELEVATED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE OVERNIGHT INTO TUE MORNING AS A FRONT RETURNS
NORTHWARD. MORNING LOW CLOUDS AND A CAP WILL LIKELY DELAY
CONVECTIVE INITIATION UNTIL THE MID AFTERNOON, BUT AFTERNOON
TEMPS IN THE LOW 90S COMBINED WITH AT LEAST LOW 70S DEWPOINTS
SHOULD RESULT IN STRONG INSTABILITY WITH 1500-2000 J/KG CAPE
PROGGED. THIS COMBINED WITH APPROACHING ANOMALOUS UPPER LEVEL
TROUGH AND ASSOCIATED STRONG WIND SPEEDS ALOFT, PARTICULARLY FOR
THE PEAK OF SUMMER SHOULD PROVIDE AMPLE FORCING AND SHEAR TO
RESULT IN A SIGNIFICANT SEVERE WX EPISODE TUE. SCATTERED
SIGNIFICANT WIND DAMAGE REPORTS SEEM LIKELY, WITH THE POTENTIAL
FOR ISOLATED TORNADOES, AND PERHAPS FLASH FLOODING. FLASH FLOOD
THREAT DOES NOT APPEAR SIGNIFICANT ENOUGH FOR A WATCH GIVEN
ANTICIPATED FAST STORM MOTIONS OF 30KT OR MORE.
BY WEDNESDAY, THERE IS SOME UNCERTAINTY WITH THE COLD FRONTAL
POSITION. WITH THE UPPER TROUGH OVERHEAD, ADDITIONAL SHOWERS
AND THUNDERSTORMS ARE LIKELY, ESPECIALLY ACROSS SOUTHERN
MARYLAND. WHILE SOME ADDITIONAL STRONG TO SEVERE THUNDERSTORMS
CAN'T BE RULED OUT IF THINGS TREND SLOWER, IT'S BEGINNING TO
APPEAR THE BEST PARAMETERS FOR THAT TO OCCUR WILL BE SHUNTED
TOWARD SOUTHEAST VIRGINIA.
KEY MESSAGE 2...COOLER THAN AVERAGE TEMPERATURES ANTICIPATED
BEGINNING THURSDAY THROUGH THE END OF THE WEEK.
KEY MESSAGE 2 DESCRIPTION...
AN UPPER-LEVEL TROUGH CENTERED OVER SOUTHEASTERN CANADA WILL TRACK
TOWARDS THE NORTHEAST ON THURSDAY, ALLOWING HIGH PRESSURE TO SLIDE
INTO THE REGION FROM THE WEST. THIS RESULTING HIGH PRESSURE COULD
PERSIST THROUGH EARLY SUNDAY. DEWPOINTS WILL ALSO TREND LOWER DURING
THIS PERIOD, RESULTING IN RELATIVELY DRY CONDITIONS. TEMPERATURES
RANGE IN THE LOW-TO-MID 80S, TRENDING SLIGHTLY BELOW AVERAGE FOR
JULY. THIS HIGH PRESSURE COULD BEGIN TO BREAK DOWN LATE THIS WEEKEND
AS A STRONG UPPER-LEVEL TROUGH BEGINS TO FORM OVER THE GREAT LAKES
REGION. AS THE TRAILING COLD FRONT TRANSITIONS EAST, HUMIDITY AND
PRECIPITATION CHANCES COULD BEGIN TO INCREASE AGAIN AT THE START OF
NEXT WEEK AS THIS SYSTEM MOVES THROUGH.
AVIATION /19Z MONDAY THROUGH SATURDAY/
MULTIPLE ROUNDS OF THUNDERSTORMS SEEM LIKELY TUE, ONE IN THE
MORNING BETWEEN 08Z-12Z, ANOTHER ONE BETWEEN 19Z-21Z, AND THIRD
ONE IN THE EVENING. STORMS COULD LINGER WELL INTO THE OVERNIGHT.
MORE STORMS ARE POSSIBLE WED, PARTICULARLY EASTERN TERMINALS.
SEVERE WIND GUSTS OF 50-KT OR GREATER ARE THE MAIN THREAT.
PREVAILING VFR CONDITIONS ARE LIKELY ACROSS TERMINALS FRIDAY AND
SATURDAY. LIGHT NORTHEAST WINDS BEGIN TO SHIFT SOUTHERLY LATE
SATURDAY NIGHT.
MARINE
STRENGTHENING SRLY FLOW TONIGHT IS EXPECTED TO RESULT IN SCA
CONDITIONS. GUSTY SSW WINDS EXPECTED TUE THROUGH TUE NIGHT WITH
LIKELIHOOD OF STRONG GUSTS OVER 33 KT, WHICH WILL LIKELY REQUIRE
SMWS. SCAS HAVE BEEN EXTENDED THROUGH TUE NIGHT INTO WED
MORNING.
WINDS STAY BELOW SCA THRESHOLDS FRIDAY AND THROUGH THE WEEKEND. 5-10
KNOT WINDS FLOW NORTHEAST BEFORE SHIFTING SOUTHERLY LATE SATURDAY
NIGHT.
TIDES/COASTAL FLOODING
INCREASING SE TO S FLOW FROM THIS EVENING INTO TUESDAY WILL
LEAD TO WATER LEVELS REACHING ACTION STAGES.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ530>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM 2 PM TO 8 PM EDT TUESDAY FOR ANZ535-
536.
SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ538-542.
DISCUSSION...LFR/SRT
AVIATION...LFR/SRT
MARINE...LFR/SRT
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