002
FXUS61 KLWX 041430
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1030 AM EDT SUN MAY 4 2025
SYNOPSIS
A SLOW-MOVING COLD FRONT WILL GRADUALLY CROSS THE MID-ATLANTIC FROM
WEST TO EAST THROUGH TUESDAY. HIGH PRESSURE MAY FOLLOW BRIEFLY FOR
WEDNESDAY, THEN ANOTHER AREA OF LOW PRESSURE MAY APPROACH LATE
IN THE WEEK.
NEAR TERM /THROUGH TONIGHT/
A SURFACE COLD FRONT ALONG THE WESTERN SLOPES OF THE HIGHEST
RIDGES OF THE APPALACHIANS WILL MOVE SLOWLY INTO OUR REGION
TODAY INTO TONIGHT. THE UPPER LEVEL LOW PRESSURE SYSTEM WILL
MEANDER AIMLESSLY AROUND CENTRAL KENTUCKY THROUGH THE SAME
PERIOD. CURRENT VISIBLE SATELLITE IMAGERY SHOWS THICK CLOUD
COVER AT ALL LEVELS IN THE CHESAPEAKE BAY AREA AND LESSER CLOUD
COVER AS ONE MOVES OR LOOKS EAST TO WEST. AS A MATTER OF FACT,
SUNSHINE IS BEGINNING TO BREAK OUT IN THE CENTRAL APPALACHIANS
AND THE SOUTH-CENTRAL SHENANDOAH VALLEY AS SOME DRIER AIR IS
WORKING INTO THE REGION FROM THE SOUTHWEST. FROM A RADAR
PERSPECTIVE, A BROAD BAND OF MODERATE TO HEAVY SHOWERS AND
EMBEDDED THUNDER IS MOVING EASTWARD ACROSS THE CHESAPEAKE BAY.
VERY LITTLE STRONG WINDS WITH THIS ACTIVITY. IT IS MAINLY HEAVY
RAIN AND OCCASIONAL THUNDER. OTHERWISE, SOME SMALLER BANDS OF
SHOWERS ARE MOVING NORTH ACROSS CENTRAL MARYLAND AND NORTHERN
VIRGINIA. NO THUNDER WITH THIS AT THIS TIME.
AS THE MORNING PROGRESSES INTO THE AFTERNOON, ADDITIONAL WIDELY
SCATTERED SHOWERS ARE EXPECTED TO DEVELOP ALMOST ANYWHERE IN OUR
REGION. THUNDERSTORMS COULD DEVELOP TOO AS ENERGY MOVES ABOUT
THE MIDDLE AND UPPER LEVEL LOW WELL TO THE WEST INTO OUR AREA.
IN THE MEANTIME, SPRINKLES OR DRIZZLE OR PERHAPS ISOLATED
SHOWERS WILL DEVELOP IN SPORADIC FASHION OVER THE NEXT 6 HOURS
OR SO. HIGH TEMPERATURES SHOULD REACH THE UPPER 60S TO MIDDLE
70S THIS AFTERNOON.
AS SHOWERS WAIN IN INTENSITY AND COVERAGE TONIGHT, SOME LOW
CLOUDS AND PATCHY FOG COULD UNFOLD DUE TO LOW LEVEL MOISTURE
LINGERING THROUGH THE PERIOD. LOWS IN THE MIDDLE 50S TO LOWER
60S.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
PREVIOUS DISCUSSION...
THE UPPER LOW AND SURFACE COLD FRONT WILL ONLY SLOWLY DRIFT EAST
THROUGH TUESDAY. ENHANCED FLOW IN THE 850-500 HPA LAYER AS WELL
AS INCREASING JET DYNAMICS FROM A WAVE AND JET STREAK ROUNDING
THE UPPER LOW WILL PROBABLY LEAD TO GREATER STORM COVERAGE ON
MONDAY AFTERNOON AND EVENING. LAPSE RATES ALOFT STEEPEN A BIT
AND FREEZING LEVELS LOWER FURTHER, BOLSTERING THE HAIL/WIND RISK
WITH ANY DEEPER STORM CORES. SHOULD GREATER HEATING AND
INSTABILITY DEVELOP, STRONG TO SEVERE STORM COVERAGE COULD BE A
LITTLE HIGHER.
ONE LAST STRONG WAVE ROUNDS THE UPPER LOW AND CROSSES THE REGION
TUESDAY, BEFORE THE UPPER LOW ITSELF PIVOTS NEARBY OR JUST TO
THE NORTH TUESDAY NIGHT. ANOTHER ROUND OF SHOWERS AND POSSIBLE
STORMS CAN BE EXPECTED AS THE UPPER LOW CROSSES.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
A BLOCKY PATTERN REMAINS IN PLACE FOR THE MIDDLE AND LATTER PART OF
THE WEEK, MEANING THAT THERE COULD BE SOME PREDICTABILITY ISSUES. AT
THIS TIME, THE UPPER LOW APPEARS IT WILL BE PULLING EAST OF THE AREA
WEDNESDAY, WHICH SHOULD RESULT IN A LOWER CHANCE OF RAIN COMPARED TO
THE PRECEDING DAYS. TEMPERATURES MAY REBOUND SLIGHTLY BUT REMAIN
NEAR NORMAL.
ON THURSDAY, A NORTHERN STREAM TROUGH WILL ROUND THE RIDGE AND DROP
TOWARD NEW ENGLAND. THIS WILL SEND A COLD FRONT SOUTH ACROSS THE
AREA. THE UPPER TROUGH WILL THEN CLOSE OFF INTO ANOTHER LOW TO OUR
EAST OR NORTHEAST THROUGH THE END OF THE WEEK. THE HIGHEST CHANCE OF
RAIN IS THURSDAY, BUT WITH LIMITED MOISTURE RETURN, BOTH RAINFALL
AMOUNTS AND CHANCES FOR THUNDERSTORMS WILL BE ON THE LOWER END OF
THE SPECTRUM.
AS LONG AS THE CLOSED LOW REMAINS TO THE EAST, THE DRIER POST-
FRONTAL AIR WILL RESULT IN LOWER RAIN CHANCES FOR FRIDAY AND
SATURDAY. TEMPERATURES MAY DROP A LITTLE BELOW NORMAL FRIDAY AND
FRIDAY NIGHT BEFORE RISING SLIGHTLY SATURDAY.
AVIATION /14Z SUNDAY THROUGH THURSDAY/
SHOWERS AND ANY THUNDERSTORMS SHOULD BE WIDELY SCATTERED AT ANY
OF THE TERMINALS THIS AFTERNOON INTO THIS EVENING. WINDS SOUTH
AND STEADY. ACTIVITY SHOULD DIMINISH BY LATE EVENING.
LOW CIGS (IFR TO LIFR) ARE ANTICIPATED LATER TONIGHT INTO MONDAY
MORNING. CONDITIONS SHOULD IMPROVE BY MIDDAY MONDAY, THEN MORE
SCATTERED THUNDERSTORM ACTIVITY COULD DEVELOP. SIMILAR WEATHER
IS EXPECTED MONDAY NIGHT THROUGH TUESDAY BEFORE IMPROVING
TUESDAY NIGHT. WITH LOWERING FREEZING LEVELS, EVEN SHALLOW
CONVECTION COULD PRODUCE SMALL HAIL/GUSTY WINDS AT TIMES.
DECREASING SHOWER CHANCES AND FEWER CLOUDS ARE FORECAST BY
WEDNESDAY AS AN UPPER-LEVEL LOW DEPARTS. AN APPROACHING COLD
FRONT COULD BRING A HIGHER CHANCE OF SHOWERS AND A FEW
THUNDERSTORMS THURSDAY. OTHERWISE, VFR CONDITIONS ARE LIKELY.
MARINE
SOUTHERLY FLOW IS EXPECTED TO INCREASE WITH A 3-6 HOUR WINDOW
OF SCA CONDITIONS LIKELY OVER THE NORTHERN BAY, MID TO UPPER
TIDAL POTOMAC, AND SMALLER TRIBUTARIES. WINDS LIKELY REMAIN
ELEVATED OVER THE WIDER WATERS THROUGH THIS EVENING. ADDITIONAL
SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THIS EVENING, AS
WELL AS MONDAY AND TUESDAY AFTERNOON/EVENING. SE FLOW COULD
APPROACH SCA LEVELS MONDAY INTO MONDAY NIGHT, OTHERWISE SUB-SCA
CONDITIONS ARE EXPECTED THROUGH TUESDAY NIGHT AS WINDS SHIFT TO
WEST.
LIGHT WEST WINDS ARE FORECAST FOR WEDNESDAY. A COLD FRONT WILL DROP
THROUGH THURSDAY AND SHIFT WINDS TO THE NORTH. SCAS MAY BE NEEDED BY
THURSDAY NIGHT, ESPECIALLY ALONG THE BAY WHERE THE NORTHERLY WINDS
COULD CHANNEL.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR MDZ008.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ530-
531-538>540-542.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ532.
SMALL CRAFT ADVISORY UNTIL 1 AM EDT MONDAY FOR ANZ533-534-537-
541-543.
SMALL CRAFT ADVISORY UNTIL 3 PM EDT THIS AFTERNOON FOR ANZ535-
536.
SYNOPSIS...DHOF
NEAR TERM...KLW/DHOF
SHORT TERM...DHOF
LONG TERM...ADS
AVIATION...ADS/KLW/DHOF
MARINE...ADS/KLW/DHOF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page