841
FXUS61 KLWX 290753
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
353 AM EDT WED APR 29 2026
WHAT HAS CHANGED
HAVE PUSHED BACK THE THREAT OF SHOWERS TO THE LATE MORNING TO
EARLY AFTERNOON PERIOD TODAY. THE SEVERE WEATHER THREAT EXISTS
THIS EVENING, BUT WILL REMAIN CONTINGENT ON SOME DEGREE OF
INSTABILITY. A COASTAL FLOOD ADVISORY WAS ISSUED EARLIER FOR
ANNAPOLIS WHICH RUNS UNTIL 7 AM. OTHERWISE, THERE HAS ALSO BEEN
A DOWNWARD TREND IN FRIDAY NIGHT'S LOW TEMPERATURES. SOME
FROST/FREEZE IS POSSIBLE ALONG THE ALLEGHENY FRONT.
KEY MESSAGES
1) SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A STRONG FRONTAL
SYSTEM THROUGH THIS EVENING.
2) WELL BELOW NORMAL TEMPERATURES ARE EXPECTED THIS WEEKEND INTO
EARLY NEXT WEEK, WITH FROST AND/OR FREEZING TEMPERATURES
POSSIBLE.
3) A PERSISTENT UPPER LOW MAY BRING ADDITIONAL SHOWERS TO THE
AREA ON THURSDAY AND FRIDAY.
DISCUSSION
KEY MESSAGE 1...SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A
STRONG FRONTAL SYSTEM THROUGH THIS EVENING.
THE EARLY MORNING FRONTAL ANALYSIS PLACES A WEAKLY DEFINED
BOUNDARY STRETCHING ACROSS WESTERN PENNSYLVANIA DOWN INTO
NORTHERN NORTH CAROLINA. SOME WEAK LOW-LEVEL CONVERGENCE ALONG
THIS FRONT HAS IGNITED SOME LOOSELY ORGANIZED SHOWERS ACROSS
PORTIONS OF THE EASTERN WEST VIRGINIA PANHANDLE. PERSONAL
WEATHER STATIONS ACROSS THIS REGION HAVE SHOWN MAINLY 0.10 TO
0.30 INCHES OF RAIN SINCE MIDNIGHT. EXPECT THESE TO GRADUALLY
DISSIPATE WHILE MOVING EASTWARD OF THE FRONTAL ZONE.
FOR THE REMAINDER OF THE FORECAST AREA, OBSERVATIONAL DATA SHOWS
WIDESPREAD LOW CLOUDS WITH BASES AROUND 1,000 TO 3,000 FEET.
THIS IS OCCURRING WITHIN LIGHT SOUTHEASTERLY FLOW AND
TEMPERATURES IN THE 50S. EXTENSIVE CLOUD COVER SHOULD LARGELY
YIELD LITTLE TEMPERATURE CHANGE HEADING TOWARD DAYBREAK.
THE MAJOR QUESTION MARK OF THE DAY IS WHETHER MORNING LOW CLOUDS
WILL ERODE ENOUGH TO SUPPORT DESTABILIZATION OF THE ATMOSPHERE
DURING THE CORE HEATING HOURS. ONE OTHER TRICKY PART OF THE
FORECAST IS SOME SOUTHWESTERLY WARM ADVECTION SHOWERS THAT PUSH
ACROSS THE AREA DURING THE LATE MORNING TO EARLY/MID AFTERNOON
TIMEFRAME. THIS SHOULD SUPPORT ADDITIONAL ISSUES WITH THICK LOW
CLOUDS. WHILE THE CURRENT FORECAST PACKAGE CALLS FOR HIGHS IN
THE MID 60S TO LOW 70S, THIS MIGHT BE SOMEWHAT OPTIMISTIC BASED
ON THE MENTIONED ISSUES.
A FORMIDABLE COLD FRONT IS FORECAST TO REACH THE BLUE RIDGE
MOUNTAINS BY THE EARLY EVENING. WHILE INSTABILITY MAY BE MEAGER,
THE DEEP-LAYER SHEAR RUNNING BETWEEN 40 TO 50 KNOTS COULD EASILY
MAKE UP FOR THIS DEFICIENCY. FURTHER, MANY FORECAST SOUNDINGS
SHOW ENLARGED CYCLONICALLY CURVED 0-3 KM HODOGRAPHS. IF STORMS
WERE TO ROOT INTO THE BOUNDARY LAYER AND REMAIN DISCRETE IN
NATURE, SOME SUPERCELL DEVELOPMENT CANNOT BE RULED OUT. THIS
WOULD SUPPORT A RISK OF AN ISOLATED TORNADO. HOWEVER, THIS
APPEARS TO BE THE CEILING OF THIS EVENT WITH THE MORE LIKELY
SCENARIO FAVORING DAMAGING WIND GUSTS ALONG AND AHEAD OF THE
COLD FRONT. PER THE LATEST STORM PREDICTION CENTER (SPC)
OUTLOOK, A MARGINAL RISK CONTINUES ACROSS A BULK OF THE REGION
OUTSIDE OF FAR NORTHEASTERN MARYLAND. ON THE RAINFALL SIDE OF
THE EQUATION, A BROAD AXIS OF 0.50 TO 0.75 INCHES OF RAIN IS
EXPECTED. THIS SHOULD PROVE TO BE MORE BENEFICIAL IN NATURE
GIVEN THE LONGSTANDING RAINFALL DEFICIT.
SHOWERS FINALLY EXIT INTO THE EASTERN SHORE AFTER MIDNIGHT.
DRIER CONDITIONS ENSUE ALONG WITH A SHIFT TO NORTHWESTERLY
WINDS. LOW TEMPERATURES TONIGHT SHOULD FALL INTO THE 40S TO LOW
50S, WITH SPOTTY UPPER 30S ALONG THE ALLEGHENY FRONT.
KEY MESSAGE 2...MULTIPLE NIGHTS OF FROST/FREEZING CONDITIONS POSSIBLE
LATE WEEK INTO THE WEEKEND.
THE UPPER LEVEL PATTERN WILL REMAIN RELATIVELY STAGNANT THIS WEEKEND
AS A DEEP UPPER LOW CONTINUES TO CIRCULATE OFF TO OUR NORTH. UPPER
TROUGHING AT MID-UPPER LEVELS AND WELL BELOW NORMAL TEMPERATURES AT
LOWER LEVELS WILL PERSIST ALONG THE EAST COAST DURING THAT TIME.
HIGH TEMPERATURES THIS WEEKEND WILL GENERALLY BE IN THE UPPER 50S TO
LOWER 60S BENEATH MOSTLY CLOUDY SKIES. DEPENDING ON HOW THE SURFACE
PATTERN SETS UP, FROST AND/OR SUB-FREEZING TEMPERATURES MAY BE
POSSIBLE EARLY SATURDAY MORNING, AND THEN AGAIN SATURDAY NIGHT.
LOCATIONS TO THE WEST OF THE BLUE RIDGE SHOULD HAVE THE GREATEST
CHANCE OF SEEING BELOW FREEZING TEMPERATURES. WITH A RELATIVELY DRY
AIRMASS IN PLACE, MOST SOLUTIONS FAVOR CONDITIONS REMAINING DRY
THROUGH THE WEEKEND, ALTHOUGH A POPUP SHOWER OR TWO CAN'T BE RULED
OUT DURING THE AFTERNOON HOURS BENEATH THE UPPER LOW. FORECAST
UNCERTAINTY INCREASES A BIT BY MONDAY AND TUESDAY, BUT MOST
SOLUTIONS FAVOR THE UPPER TROUGH MOVING OUT AND A RESULTANT WARMING
TREND IN TEMPERATURES.
KEY MESSAGE 3...A PERSISTENT UPPER LOW MAY BRING ADDITIONAL
SHOWERS TO THE AREA ON THURSDAY AND FRIDAY.
BEHIND THE MID-WEEK FRONTAL SYSTEM, THE PATTERN ALOFT WILL SEE
AN EXPANSIVE UPPER LOW OVERSPREAD THE GREAT LAKES INTO THE
NORTHEASTERN U.S. THIS COMES WITH BELOW AVERAGE TEMPERATURES AS
WELL. FOR LATE APRIL/EARLY MAY STANDARDS, 500-MB HEIGHT
ANOMALIES ARE FAIRLY IMPRESSIVE BEING IN THE 1.5 TO 2 STANDARD
DEVIATION BELOW AVERAGE RANGE. GENERAL UPWARD MOTIONS UNDERNEATH
THIS CIRCULATION WILL AID IN SOME SHOWER DEVELOPMENT EACH DAY
THROUGH FRIDAY.
FOR THURSDAY, THE AIR MASS BEHIND THE COLD FRONT WILL BE DRY AND
BREEZY WITH NORTHWESTERLY GUSTS TO AROUND 20 TO 25 MPH.
THEREFORE, ANY MENTION OF SHOWERS IS CONFINED TO ALONG/WEST OF
THE ALLEGHENY FRONT WHERE UPSLOPE FLOW WILL LOCALLY ENHANCE
LIFT. IF THE SHOWERS OCCUR EARLY ENOUGH, SOME OF THE HIGHEST
ELEVATIONS COULD EVEN SEE A FEW SNOWFLAKES MIXING IN.
BY FRIDAY, THE CENTER OF THE UPPER LOW MOVES ACROSS SOUTHEASTERN
ONTARIO. A SERIES OF PERTURBATIONS CIRCULATING CYCLONICALLY
AROUND THIS TROUGH WILL HELP BRING ISOLATED/SCATTERED SHOWERS TO
THE AREA. THIS WILL PARTICULARLY BE THE CASE DURING THE
AFTERNOON HOURS GIVEN ENHANCED LIFT. FORECAST SOUNDINGS SHOW
FAIRLY HIGH BASES TO THESE SHOWERS, SO EVAPORATIVE COOLING
EFFECTS BELOW COULD YIELD SOME BRIEF GUSTY WINDS. A FEW SHOWERS
COULD LINGER INTO THE EVENING BUT EXPECT A DOWNWARD TREND WITH
THE LOSS OF HEATING. A CHILLY NIGHT LIES AHEAD AS LOWS FALL INTO
THE UPPER 30S TO MID 40S (LOW/MID 30S ACROSS THE ALLEGHENIES).
WITH THE 1991-2020 MEDIAN LAST FREEZE DATE ON MAY 1 ACROSS THE
ALLEGHENIES, FROST/FREEZE PRODUCTS WILL COMMENCE.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
LIGHT SOUTHEASTERLY FLOW CONTINUES EARLY THIS MORNING WITH
WIDESPREAD LOW STRATUS IN PLACE. MUCH OF THESE FEATURE CLOUD
BASES AROUND 1,500 TO 2,500 FEET (MVFR). WITH LOW CLOUDS IN THE
PICTURE TODAY, RESTRICTIONS ARE EXPECTED THROUGHOUT THE DAY.
RAIN SHOWERS ARRIVE LATE THIS MORNING INTO THE EARLY/MID-
AFTERNOON BEFORE A STRONGER ROUND OF STORMS MAY IMPACT THE
TERMINALS BETWEEN 21Z-01Z. THE DEGREE OF SEVERE WEATHER THREAT
IS MORE UNKNOWN, BUT THESE CELLS WILL HAVE THE POTENTIAL OF
PRODUCING STRONG/GUSTY WINDS THIS EVENING. ANY CONVECTIVE THREAT
WINDS DOWN BY LATE THIS EVENING WHILE WINDS SHIFT TO
NORTHWESTERLY OVERNIGHT BEHIND THE COLD FRONT. VFR CONDITIONS
RETURN INTO THE NIGHT.
FOR THURSDAY AND FRIDAY, EXPECT MAINLY VFR CONDITIONS. BREEZY
NORTHWESTERLIES ARE LIKELY TO START OFF WITH AFTERNOON GUSTS TO
AROUND 20 TO 25 KNOTS. ANY SHOWER CHANCES ARE LIKELY RELEGATED
TO THE ALLEGHENY FRONT. AN UPPER LOW TO THE NORTH WILL BRING A
BETTER SHOT OF ISOLATED/SCATTERED SHOWERS ON FRIDAY. THESE COULD
SUPPORT A FEW BRIEF RESTRICTIONS AND SOME LOCALLY GUSTY
DOWNDRAFT WINDS. OTHERWISE, THE OVERALL WINDS WILL REMAIN OUT OF
THE WEST.
VFR CONDITIONS ARE EXPECTED AT THE TERMINALS THIS WEEKEND. WINDS ARE
FORECAST TO BE OUT OF THE NORTHWEST ON SATURDAY, AND THEN WEST ON
SUNDAY.
MARINE
THE EARLY MORNING WINDS ACROSS THE MARINE WATERS ARE MAINLY OUT
OF THE SOUTHEAST WITH GUSTS UP TO 10 TO 15 KNOTS. EXPECT THESE
TO FURTHER INCREASE THROUGH THE DAY WITH SMALL CRAFT ADVISORIES
IN EFFECT FOR ALL WATERS STARTING AT 11 AM. THESE REMAIN IN
PLACE UNTIL EARLY THURSDAY MORNING AS WINDS SHIFT TO
NORTHWESTERLY BEHIND TONIGHT'S COLD FRONT. ADDITIONALLY, THIS
FRONT WILL POSE A RISK OF SOME STRONGER STORMS WHICH MAY REQUIRE
SOME EVENING SPECIAL MARINE WARNINGS. SUCH STORMS PUSH INTO THE
EASTERN SHORE BY AFTER MIDNIGHT.
BREEZY NORTHWESTERLY WINDS ARE EXPECTED ON THURSDAY WITH SMALL
CRAFT ADVISORIES LIKELY NEEDED THROUGH MUCH OF THE DAY. WINDS
BEGIN TO DECREASE INTO THURSDAY NIGHT AS WELL AS FRIDAY WITH A
SHIFT TO WESTERLIES. AN UPPER LOW WILL AID IN SOME SHOWER
DEVELOPMENT ON FRIDAY, MANY OF WHICH WILL BE HIGH BASED. SOME OF
THESE COULD PRODUCE LOCALLY GUSTY WINDS SO MARINE WEATHER
STATEMENTS MAY BE NEEDED AT TIMES.
SUB-SCA LEVEL NORTHWESTERLY WINDS ARE EXPECTED OVER THE WATERS ON
SATURDAY. WESTERLY GUSTS MAY REACH LOW-END SCA LEVELS ON SUNDAY.
TIDES/COASTAL FLOODING
SOUTHEASTERLY FLOW CONTINUES TO KEEP ANOMALIES ELEVATED AT MOST
OF THE TIDAL SITES. MANY LOCATIONS WILL REACH ACTION STAGE
DURING HIGH TIDE THROUGH TONIGHT, WITH MINOR TIDAL FLOODING
EXPECTED AT ANNAPOLIS. A FEW OTHER TIDAL SITES LIKE ALEXANDRIA,
DAHLGREN, AND HAVRE DE GRACE COULD GET CLOSE DURING THE HIGHER
OF THE TWO ASTRONOMICAL HIGH TIDES, AS WELL. WATER LEVELS BEGIN
TO DROP OFF BY THURSDAY AS WINDS SHIFT TO NORTHWESTERLY.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 6 AM EDT
THURSDAY FOR MDZ008.
COASTAL FLOOD ADVISORY UNTIL 7 AM EDT THIS MORNING FOR MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 6 AM EDT
THURSDAY FOR ANZ530>543.
DISCUSSION...BRO/KJP
AVIATION...BRO/KJP
MARINE...BRO/KJP
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