834
FXUS61 KLWX 280129
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
929 PM EDT MON JUL 27 2026
WHAT HAS CHANGED
HEAVY SHOWERS AND STRONG TO SEVERE THUNDERSTORMS IN AND NEAR
BALTIMORE CITY AND ANNE ARUNDEL COUNTY HAVE LEAD TO SEVERE
THUNDERSTORM WARNINGS AND FLASH FLOOD WARNINGS EARLY THIS
EVENING. WHILE THE SEVERE THUNDERSTORM WARNING HAS EXPIRED, THE
FLASH FLOOD WARNING REMAINS IN EFFECT.
KEY MESSAGES
- SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY WITH A STRONG
FRONTAL PASSAGE.
- A FEW CHANCES FOR RAIN THROUGH THE WEEKEND, BUT NO HAZARDOUS
WEATHER EXPECTED BETWEEN WEDNESDAY AND SUNDAY AT THIS TIME.
DISCUSSION
KEY MESSAGE 1...SLIGHT RISK OF SEVERE THUNDERSTORMS TUESDAY
WITH A STRONG FRONTAL PASSAGE.
KEY MESSAGE 1 DESCRIPTION...
WE CAN'T RULE OUT ADDITIONAL SHOWERS OR A THUNDERSTORM OR TWO IN
ANY ONE PORTION OF OUR FORECAST REGION THE REMAINDER OF THE
EVENING. PREVIOUS CONVECTION IS WEAKENING OR HAS WEAKENED.
THERE REMAINS ABOUT 1000 J/KG OF ML CAPE AND 20 TO 30 KNOTS OF
WIND SHEAR OVER A LARGE PORTION OF OUR REGION. THEREFORE,
INSTABILITY AND SHEAR IS PRESENT TO SUPPORT ADDITIONAL
CONVECTION THE REMAINDER OF THE EVENING.
AS FOR AFTER MIDNIGHT INTO DAYBREAK TUESDAY, MODELS ARE DIVERSE
IN A SOLUTION THAT A CLUSTER OF SHOWERS AND STRONG THUNDERSTORMS
OR MULTIPLE INDIVIDUAL THUNDERSTORMS COULD DEVELOP WELL TO THE
NORTHWEST AND MOVE INTO NORTHWESTERN AND NORTH-CENTRAL ZONES
LATER TONIGHT TOWARD THE EARLY MORNING RUSH. THERE IS AN
INCREASED CHANCE THAT WE WILL SEE SCATTERED AREAS OF SEVERE
THUNDERSTORMS IN OUR FORECAST REGION TUESDAY AFTERNOON INTO THE
EVENING. THE MAIN TIMEFRAME OF CONCERN APPEARS TO BE 2PM TO 8PM.
WE COULD SEE MULTIPLE LINEAR SEGMENTS OF THUNDERSTORMS OR A
CLUSTER THAT MATERIALIZES, SPREADS OUTWARD, AND GENERATES
ADDITIONAL STRONG TO SEVERE THUNDERSTORMS. ALL OF THIS RELIES ON
A SURFACE LOW PRESSURE SYSTEM THAT WILL DROP DOWN FROM THE LOWER
GREAT LAKES AND MIDWEST AND PUSH ACROSS THE APPALACHIANS DURING
THE PEAK HEATING OF THE DAY. THE MAIN THREATS TUESDAY AFTERNOON
INTO TUESDAY EVENING WILL BE DAMAGING WINDS AND HEAVY DOWNPOURS
THAT COULD LEAD TO INSTANCES OF FLASH FLOODING. WE COULD ALSO
ENCOUNTER LARGE HAIL AS TOPS OF SEVERE THUNDERSTORM COULD POKE
SEVERAL THOUSAND FEET UPWARDS BEFORE COLLAPSING. THE STORMS
PREDICTION CENTER HAS MOST OF OUR REGION IN A SLIGHT RISK FOR
SEVERE THUNDERSTORMS. IT IS AROUND MID-EVENING THAT A COLD FRONT
IS EXPECTED TO PUSH THROUGH THE REGION AND BRING SLIGHTLY COOLER
AND DRIER AIR INTO THE REGION THE REMAINDER OF TUESDAY NIGHT
INTO WEDNESDAY.
KEY MESSAGE 2...A FEW CHANCES FOR RAIN THROUGH THE WEEKEND,
BUT NO HAZARDOUS WEATHER EXPECTED BETWEEN WEDNESDAY AND SUNDAY
AT THIS TIME.
KEY MESSAGE 2 DESCRIPTION...
THE UPPER-LOW OVER THE NORTHEAST CONUS WILL LINGER THROUGH FRIDAY
BEFORE FINALLY PULLING OFF TO THE NORTHEAST. AS A RESULT, THERE WILL
BE NON-ZERO RAIN CHANCES EACH DAY, PRIMARILY AREAS FURTHER
NORTH AND EAST. FRIDAY COULD BE DRY FOR ALL, BUT STILL A BIT OF
UNCERTAINTY REGARDING EXACTLY WHEN THE UPPER LOW DEPARTS.
A BROAD UPPER-LEVEL TROUGH WILL BEGIN TO FORM OVER THE OHIO RIVER
VALLEY OVER THE WEEKEND. AS THIS TROUGH TRACKS EAST, CLOUD COVER &
PRECIPITATION CHANCES WILL BEGIN TO INCREASE, PARTICULARLY BETWEEN
SATURDAY EVENING AND SUNDAY AS THE LOW TRACKS OFFSHORE AND TOWARDS
THE NORTHEAST. SEVERE PROBABILITIES LOOK LOW AT THIS TIME, WITH A
PRETTY WEAK WIND FIELD ALOFT. NONETHELESS, WEEKEND SHOWERS ARE
POSSIBLE WITH THIS SYSTEM SHOULD THE SYNOPTIC SETUP CONTINUE TO
TREND TOWARD DEVELOPMENT OVER THE MIDWEST.
AVIATION /01Z TUESDAY THROUGH SATURDAY/
ANY SHOWERS OR STRONG THUNDERSTORM THAT COULD DEVELOP THE
REMAINDER OF THE NIGHT OVERNIGHT AND EARLY TUESDAY MORNING AND
ADDITIONAL STRONG TO SEVERE THUNDERSTORMS THAT COULD DEVELOP
TUESDAY AFTERNOON AND EVENING COULD REDUCE CEILINGS AND
VISIBILITY TO MVFR OR IFR BRIEFLY.
VFR CONDITIONS ARE EXPECTED ON FRIDAY. HOWEVER, AN UPPER-LOW TO OUR
NORTHEAST COULD BRING SOME SHOWERS CLOSE TO BWI/MTN. THIS IS A VERY
LOW LIKELIHOOD SCENARIO AT THIS TIME, BUT CAN'T COMPLETELY RULE
IT OUT. EITHER WAY, NO SIGNIFICANT REDUCTIONS APPEAR LIKELY AT
THIS TIME.
SATURDAY APPEARS TO BE ANOTHER DAY WITH OCCASIONAL SHOWERS POSSIBLE,
BUT VFR CONDITIONS OTHERWISE.
MARINE
WINDS WILL INCREASE OVERNIGHT INTO TUESDAY IN A SOUTHERLY FLOW
WITH SCA CONDITIONS TUESDAY INTO TUESDAY NIGHT. SEVERE
THUNDERSTORMS TUESDAY AND TUESDAY EVENING MAY ALSO REQUIRE
SMWS. WINDS SHIFT TO NW TUE NIGHT BEHIND A COLD FRONT WITH SCA
CONDITIONS EXPECTED INTO FRIDAY MORNING.
WINDS WILL DROP BELOW SCA CRITERIA FOR FRIDAY AND CONTINUE FOR MUCH
OF SATURDAY. HOWEVER, AS WINDS TURN SOUTHERLY LATE SATURDAY
AFTERNOON/EVENING, WINDS COULD APPROACH SCA CRITERIA AS THEY CHANNEL
UP THE CHESAPEAKE BAY.
TIDES/COASTAL FLOODING
TIDAL ANOMALIES REMAIN SLIGHTLY ELEVATED DURING THE FULL MOON PHASE,
THUS PUSHING MOST SITES INTO ACTION STAGE. ANNAPOLIS IS FORECAST TO
HIT MINOR FLOOD STAGE DURING THE HIGHER HIGH TIDE CYCLE THROUGH
WEDNESDAY, BUT OTHER SENSITIVE SPOTS COULD COME CLOSE AS WELL
(HAVRE DE GRACE, AND ALEXANDRIA).
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY FROM 8 AM TO 8 PM EDT TUESDAY FOR MDZ008.
COASTAL FLOOD ADVISORY FROM 3 AM TO 8 AM EDT TUESDAY FOR
MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM TO 8 PM EDT TUESDAY FOR
ANZ530>533-537>542.
SMALL CRAFT ADVISORY FROM 8 AM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ534-543.
SMALL CRAFT ADVISORY FROM 1 PM TO 8 PM EDT TUESDAY FOR ANZ535-
536.
DISCUSSION...LFR/KLW/CJL
AVIATION...LFR/KLW/CJL
MARINE...LFR/KLW/CJL
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