679
FXUS61 KLWX 281836
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
236 PM EDT FRI MAR 28 2025
SYNOPSIS
A WARM FRONT APPROACHING FROM THE OHIO RIVER VALLEY WILL LIFT ACROSS
THE MID-ATLANTIC TODAY, THEN LINGER NEAR THE AREA THIS WEEKEND. LOW
PRESSURE WILL MOVE ACROSS THE GREAT LAKES SUNDAY INTO MONDAY
DRAGGING A COLD FRONT ACROSS THE REGION. HIGH PRESSURE WILL
FOLLOW FOR TUESDAY INTO WEDNESDAY, THEN ANOTHER FRONTAL SYSTEM
WILL APPROACH WEDNESDAY INTO THURSDAY.
NEAR TERM /THROUGH TONIGHT/
RADAR TRENDS PAINT A VERY EXPECTED PICTURE REGARDING TODAY'S
FORECAST. "SHOWER" COVERAGE IS ON THE INCREASE, HOWEVER IT IS
JUST TOO DRY FOR NOW TO ALLOW ANY OF IT TO REACH THE SURFACE. AT
THIS POINT, THIS ACTIVITY HAS BEEN OUT ACROSS THE POTOMAC
HIGHLANDS, SLOWLY SPREADING EASTWARD. MADE SOME SIGNIFICANT
CHANGES IN THE TIMING OF PRECIP TODAY, AS WELL AS THE
PROBABILITIES, ESPECIALLY SOUTH OF I-66. GIVEN THE LATEST
TRENDS, THINK MOST PLACES STRUGGLE TO GET MORE THAN A FEW
HUNDREDTHS OF AN INCH OF RAIN. AREAS ALONG THE MD/PA BORDER MAY
GET SLIGHTLY CLOSER TO A TENTH OF AN INCH.
SHOWERS WILL QUICKLY LIFT NORTH OF THE REGION THIS EVENING
ALONG WITH THE WARM FRONT, THOUGH IT COULD GET HUNG UP A BIT
NEAR NE MD. GIVEN SOME LINGERING CLOUDS AND SOUTHWEST BREEZES,
TEMPERATURES WILL BE MILD TONIGHT WITH LOWS IN THE 50S AND LOWER
60S EXPECTED.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
THE REGION SHOULD BE FIRMLY BEHIND/SOUTH OF THE WARM FRONT
SATURDAY. DESPITE A MIX OF SUN AND CLOUDS, A STEADY DOWNSLOPING
WEST TO SOUTHWEST WIND SHOULD RESULT IN THIS YEAR'S FIRST
80-DEGREE DAY FOR MUCH OF THE MID-ATLANTIC. THIS WILL ALSO
RESULT IN SOME SUBSTANTIAL DRYING AT THE SURFACE, WHICH COULD
LEAD TO A CONDITIONAL FIRE WEATHER THREAT, SEE FIRE WEATHER
DISCUSSION BELOW. HOWEVER, THERE IS ALSO AT LEAST A SLIGHT
CHANCE OF SOME POP-UP SHOWERS OVER THE HIGHER ELEVATIONS
TOMORROW. THESE WOULD LIKELY BE HIGH-BASED AND HONESTLY MAY JUST
BE MORE CLOUD THAN ANYTHING. HOWEVER, DID INTRODUCE SOME 15 TO
20 POPS ALONG/WEST OF THE BLUE RIDGE TO ACCOUNT FOR THIS THREAT.
A BROAD TROUGH APPROACHING FROM THE MIDWEST WILL RESULT IN
LOWERING HEIGHTS SATURDAY NIGHT. LOW-LEVEL DRY AIR WILL ONCE
AGAIN BE IN PLACE, WHICH SHOULD KEEP MOST SHOWER ACTIVITY NEAR
THE APPALACHIANS THROUGH DAWN ON SUNDAY.
THE LONGWAVE TROUGH'S FORWARD (EASTWARD) PROGRESSION WILL BE
SLOW OVERALL, THOUGH FLOW ALOFT AHEAD OF THE TROUGH WILL BE
STRENGTHENING DUE TO A TIGHTENING GRADIENT WITH A RIDGE OFF THE
COAST. AN EMBEDDED SHORTWAVE LOOKS TO CURL BY TO THE NORTHWEST
OF THE LOCAL AREA SUNDAY. MOST ACTIVITY MAY STAY CLOSER TO THE
SHORTWAVE. BUT, A BROAD WARM SECTOR AND CONTINUED HEIGHT FALLS
COUPLED WITH A WARM AND AN INCREASINGLY MOIST AIRMASS COULD
RESULT IN ENOUGH LIFT AND INSTABILITY FOR AT LEAST SCATTERED
SHOWERS AND PERHAPS A FEW THUNDERSTORMS. ALTHOUGH FLOW ALOFT
WILL BE INCREASING, A LACK OF STRONGER FORCING AND INSTABILITY
SHOULD KEEP THUNDERSTORM STRENGTH IN CHECK SUNDAY. HOWEVER, ANY
MESOSCALE INFLUENCES NOTED WITH THE UPSTREAM SHORTWAVE WILL NEED
TO BE MONITORED IN THE DAYS AHEAD GIVEN THE SHEAR PROFILES.
MORE APPRECIABLE HEIGHT FALLS ENSUE LATE SUNDAY NIGHT, WITH A
HIGHER POTENTIAL OF MORE ORGANIZED SHOWER ACTIVITY REACHING THE
APPALACHIANS OVERNIGHT INTO EARLY MONDAY MORNING.
LONG TERM /MONDAY THROUGH FRIDAY/
MODEL GUIDANCE IS IN REASONABLY GOOD AGREEMENT THAT A POTENT
SHORTWAVE AND ASSOCIATED SURFACE LOW WILL TRACK NORTHEASTWARD FROM
THE GREAT LAKES INTO THE ST. LAWRENCE VALLEY ON MONDAY. A TRAILING
COLD FRONT WILL EXTEND SOUTHWESTWARD FROM THE LOW, AND WILL APPROACH
THE AREA FROM THE OHIO VALLEY OVER THE COURSE OF THE DAY. LARGE
SCALE ASCENT DOWNSTREAM OF AN APPROACHING BROADER LONGWAVE TROUGH
WILL LEAD TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE
AREA MONDAY AFTERNOON INTO MONDAY EVENING. PRIOR TO THE STORMS, IT
SHOULD BE A VERY WARM DAY, WITH HIGHS CLIMBING INTO THE MID 70S TO
LOWER 80S. WHEN COMBINED WITH DEWPOINTS CLIMBING INTO THE UPPER 50S
TO NEAR 60 AND COOLING TEMPERATURES ALOFT, THIS WILL RESULT IN THE
DEVELOPMENT OF SURFACE BASED INSTABILITY, WITH MANY MODEL SOLUTIONS
SHOWING AROUND 500-1000 J/KG OF MLCAPE. WINDS ALOFT WILL ALSO BE
RATHER IMPRESSIVE, WITH A LOW-LEVEL JET OF AROUND 50 KNOTS AT 850
HPA, AND CONTINUED STRONG WINDS UP THROUGH THE TROPOPAUSE. SUCH A
COMBINATION OF INSTABILITY AND AMPLE DEEP LAYER SHEAR MAY LEAD TO
THE DEVELOPMENT OF SEVERE THUNDERSTORMS MONDAY AFTERNOON INTO MONDAY
EVENING. SPC CURRENTLY HAS ALL OF THE FORECAST AREA OUTLOOKED IN A
SLIGHT RISK FOR SEVERE THUNDERSTORMS ON MONDAY.
THE SYSTEM'S COLD FRONT WILL MOVE THROUGH THE AREA MONDAY NIGHT,
WITH HIGH PRESSURE BUILDING TO OUR NORTH ON TUESDAY. NORTH TO
NORTHWESTERLY WINDS WILL TRANSPORT A COOLER AND MUCH DRIER AIRMASS
INTO THE REGION. MOSTLY SUNNY SKIES ARE EXPECTED, WITH HIGH
TEMPERATURES IN THE MID 50S TO LOWER 60S FOR MOST.
MOST MODEL SOLUTIONS POINT TOWARD A STRONG AREA OF LOW PRESSURE
DEVELOPING OVER THE CENTER OF THE COUNTRY AND THEN TRACKING
NORTHEASTWARD TOWARD THE GREAT LAKES DURING THE MIDDLE TO LATTER
PORTIONS OF THE WEEK. THIS SYSTEM COULD POTENTIALLY PRODUCE
ADDITIONAL SHOWERS LOCALLY AS EARLY AS WEDNESDAY AFTERNOON, WITH
THUNDERSTORMS ALSO A POSSIBILITY DURING THE DAY THURSDAY.
CONSIDERABLE SPREAD IN MODEL GUIDANCE STILL EXISTS WITH REGARD TO
THIS SYSTEM, BUT MOST SOLUTIONS HAVE THE STRONGEST FORCING FOR
ASCENT PASSING WELL OFF TO OUR NORTH AND WEST. REGARDLESS OF HOW
MUCH RAIN WE RECEIVE, THE TREND SHOULD BE TOWARD A RETURN TO WARMER
TEMPERATURES BY THURSDAY AS THE AFOREMENTIONED SYSTEM TRACKS TO OUR
NORTHWEST, AND SOUTHERLY FLOW OUT AHEAD OF THE SYSTEM ADVECTS WARMER
AIR BACK INTO THE REGION. HIGH TEMPERATURES MAY MAKE A RUN AT 80
DEGREES AGAIN BY THURSDAY.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
DESPITE THE PASSAGE OF A WARM FRONT TODAY, ANTECEDENT DRY AIR IN
THE LOW LEVELS SHOULD KEEP RESTRICTIONS AT A MINIMUM FOR ANY
SHOWERS THAT DO MANAGE TO DEVELOP. BRIEF VSBY REDUCTIONS ARE
POSSIBLE IN ANY MODERATELY HEAVY SHOWER ACTIVITY, BUT CONFIDENCE
IN SUCH RESTRICTIONS REMAINS LOW ENOUGH TO NOT HAVE INCLUDED IN
THE 18Z TAFS OUTSIDE OF MRB, WHERE CONFIDENCE IS SLIGHTLY HIGHER.
STARTING TO SEE THESE SHOWERS DEVELOP OVER THE HIGHER ELEVATIONS
ON RADAR, BUT NOT MUCH IS GETTING TO THE SURFACE AT THIS POINT.
OTHERWISE, A PERIOD OF LLWS IS LIKELY LATER THIS EVENING INTO
EARLY SATURDAY MORNING AS A STRENGTHENING LLJ PIVOTS OVERHEAD.
SURFACE WINDS WILL GENERALLY BE JUST WEST OF SOUTH THROUGH
TONIGHT AOB 10 KTS, THOUGH A BRIEF (FEW HOUR) WINDOW OF HIGHER
SPEEDS AND CORRESPONDING GUSTS AROUND 20 KTS IS LIKELY THIS
AFTERNOON. ADDITIONAL GUSTINESS IS LIKELY IN W/SW FLOW SATURDAY
(20-25 KTS) WITH VFR EXPECTED.
MVFR CIGS ARE POSSIBLE LATE SATURDAY NIGHT INTO SUNDAY MORNING
AS THE COLUMN MOISTENS WELL AHEAD OF AN APPROACHING TROUGH/COLD
FRONT, THOUGH VFR SEEMS MOST LIKELY TO PREVAIL AT THIS TIME.
WINDS ARE LIKELY TO TURN BACK TO A MORE SOUTHERLY DIRECTION WITH
DAYTIME GUSTS ONCE AGAIN ECLIPSING 20-25 KTS. SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON
INTO EARLY SUNDAY EVENING. SCATTERED SHOWERS MAY LINGER SUNDAY
NIGHT, POSSIBLY RESULTING IN SUB-VFR AT TIMES.
PREVAILING VFR CONDITIONS ARE EXPECTED ON BOTH MONDAY AND TUESDAY,
BUT TEMPORARY DROPS TO SUB-VFR CONDITIONS MAY BE POSSIBLE IN
THUNDERSTORMS MONDAY AFTERNOON INTO MONDAY EVENING. WINDS WILL BE
OUT OF THE SOUTH TO SOUTHWEST ON MONDAY, AND THEN OUT OF THE
NORTHWEST ON TUESDAY.
MARINE
WINDS WILL GRADUALLY INCREASE AHEAD OF AN APPROACHING WARM
FRONT THROUGH THIS EVENING, WITH THE MOST LIKELY AREA OF
FREQUENT GUSTS LOCATED IN THE VICINITY OF THE MID/UPPER TIDAL
POTOMAC RIVER WHERE MIXING WILL BE MORE EFFICIENT. SCAS GO INTO
EFFECT AT 3 PM AS A RESULT.
TONIGHT, A STRENGTHENING LOW-LEVEL JET WILL MOVE OVER THE WIDER
WATERS, WITH ANOTHER PERIOD OF SCA GUSTS MOST LIKELY OVER THESE
WIDER WATERS ONCE AGAIN THROUGH SATURDAY MORNING. SCAS CONTINUE
DURING THIS TIME.
INCREASING WEST TO SOUTHWEST WIND GUSTS ARE ANTICIPATED
ESPECIALLY OVER/NEAR THE NORTHERN AND NARROWER WATERWAYS
SATURDAY. AIR TEMPERATURES WILL BE MUCH WARMER THAN THE WATER
TEMPERATURES BY SATURDAY AFTERNOON, RESULTING IN THE STRONGEST
GUSTS NEAR THE SHORE. MARINERS SHOULD BE MINDFUL THAT ALTHOUGH
AIR TEMPERATURES WILL BE WARM (AROUND 80 NEAR THE SHORE OR JUST
INLAND), WATER TEMPERATURES ARE STILL COLD (IN THE 40S AND 50S).
SCAS MAY NOT BE NEEDED DUE TO SUCH A SHARP INVERSION NEAR THE
SURFACE LIKELY KEEPING WINDS OFF THE MAIN WATERWAYS.
SHOWERS AND PERHAPS A THUNDERSTORM OR TWO ARE POSSIBLE SUNDAY
AFTERNOON INTO SUNDAY NIGHT WITH CONTINUED PERIODS OF S/SW
GUSTINESS.
SCA CONDITIONS APPEAR LIKELY WITHIN SOUTH TO SOUTHWEST FLOW ON
MONDAY, AND THEN POSSIBLE IN NORTHWESTERLY FLOW ON TUESDAY.
FIRE WEATHER
STRONG W TO WSW WINDS ON SATURDAY AFTERNOON WILL LEAD TO A
SUBSTANTIAL WARMING/DRYING EVENT OVER MUCH OF THE REGION. HIGH
TEMPERATURES IN THE UPPER 70S TO LOW 80S. THIS PAIRED WITH RH
VALUES POTENTIALLY AS LOW AS THE LOW 20S AND WIND GUSTS IN THE
20 TO 25 MPH RANGE. AS A RESULT, I AM MILDLY CONCERNED ABOUT A
CONDITIONAL FIRE WEATHER THREAT DURING THE AFTERNOON. THIS DAY
IS HONESTLY PRETTY SIMILAR TO THE PAST SEVERAL FIRE WEATHER
DAYS, VERY MARGINAL WINDS AND LOW RH. THE AFTERNOON RH VALUES
MAY DROP AS LOW AS THE LOW 20S, BUT NOT AS CONFIDENT IN THAT AS
I HAVE BEEN IN PREVIOUS DAYS. HOWEVER, THE KEY DIFFERENCE WITH
THIS EVENT IS THE VERY WARM TEMPERATURES. FUELS WILL BE HOT AND
DRY, ASSUMING THEY DON'T GET RAINED ON MUCH THIS AFTERNOON
(FRIDAY). ONE FINAL VARIABLE TO GO INTO THIS IS THE FACT THAT
FORESTS ARE STARTING THEIR GREEN UP PROCESS, SO THAT WILL HAVE
TO START BEING A FACTOR IN THESE DECISIONS AS WELL.
ALL IN ALL, AN SPS FOR INCREASED FIRE DANGER SEEMS TO BE THE
BEST APPROACH, IF ANYTHING. WILL LOOK INTO THIS THREAT FURTHER
ON THE EVENING AND OVERNIGHT SHIFTS, WITH A FINAL DECISION
MADE BY TOMORROW MORNING.
TIDES/COASTAL FLOODING
A STRONG COLD FRONT WILL APPROACH ON MONDAY AFTERNOON. STRONG
SOUTHERLY FLOW AHEAD OF THIS FRONT WILL BRING TIDAL ANOMALIES UP
GRADUALLY THROUGH THE WEEKEND BEFORE PEAKING INTO MONDAY AHEAD
OF THE FRONT ITSELF. IT IS POSSIBLE THAT THE MORE SENSITIVE
TIDAL AREAS COULD APPROACH ACTION TO NEAR MINOR FLOOD STAGE, HUT
STILL A LOT OF SPREAD AMONGST THE DIFFERENT PIECES OF GUIDANCE
AT THIS POINT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SATURDAY FOR ANZ532>534-
537-540-541-543.
SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ535-
536.
SYNOPSIS...DHOF
NEAR TERM...CJL
SHORT TERM...DHOF/CJL
LONG TERM...KJP
AVIATION...DHOF/CJL/KJP
MARINE...DHOF/CJL/KJP
FIRE WEATHER...CJL
TIDES/COASTAL FLOODING...CJL
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