442
FXUS61 KLWX 290128
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
928 PM EDT FRI MAR 28 2025
SYNOPSIS
A WARM FRONT WILL LIFT NORTH OF THE AREA BY SATURDAY. 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 /UNTIL 6 AM SATURDAY MORNING/
THE WARM FRONT STRADDLING THE AREA IS DIFFUSE AND HAS BEEN
MUDDLED BY THE LIGHT SHOWERS THAT MOVED ACROSS THE AREA. SINCE
THEY FELL THROUGH A DRY, DEEP MIXED LAYER, ONLY A FEW HUNDREDTHS
OF AN INCH ACCUMULATED AT MOST. THEY HAVE ALSO LEFT A STRIPE OF
LOCALLY COOLER AND MOISTURE SURFACE CONDITIONS ALONG WITH
VARIABLE WINDS. AT THIS POINT, ANY REMAINING SHOWERS HAVE A
TRAJECTORY TO AFFECT NORTHEAST MARYLAND AND SHOULD EXIT BY
MIDNIGHT OR SO. GIVEN A WINDOW OF CLEARING WITH LIGHT WINDS, A
FEW PATCHES OF FOG COULD DEVELOP, ALTHOUGH PLACES THAT SATURATED
SUFFICIENTLY ARE FAIRLY ISOLATED. ANOTHER RESULT IS THAT SOME
TEMPERATURES ARE ALREADY AT OR BELOW PREVIOUS FORECAST LOWS, SO
SOME SLIGHT DOWNWARD ADJUSTMENTS WERE REQUIRED. HOWEVER, BETWEEN
THE RISING DEW POINTS, SOUTHERLY WIND TRAJECTORY, AND ANOTHER
BATCH OF MID LEVEL CLOUDS DURING THE SECOND HALF OF THE NIGHT,
MOST LOCATIONS WILL REMAIN IN THE 50S.
SHORT TERM /6 AM SATURDAY MORNING 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 /01Z SATURDAY THROUGH WEDNESDAY/
MOST SHOWER ACTIVITY HAS ENDED, ALTHOUGH SOME SPRINKLES COULD
AFFECT MTN THROUGH 02 OR 03Z. IN THE WAKE OF THESE SHOWERS,
WINDS HAVE TAKEN ON VARIABLE DIRECTIONS AS THE WARM FRONT HAS
NOT PROGRESSED ENTIRELY THROUGH THE AREA. HOWEVER, SPEEDS SHOULD
REMAIN AROUND 6 KT OR LESS.
A PERIOD OF LLWS IS LIKELY OVERNIGHT AS A STRENGTHENING LLJ
PIVOTS OVERHEAD. SURFACE WINDS WILL GENERALLY BE JUST WEST OF
SOUTH THROUGH TONIGHT AOB 10 KTS, WITH SW WINDS PEAKING AROUND
40 KT AT 2000FT. THE INVERSION WILL GRADUALLY BREAK BY SATURDAY
AFTERNOON, AND ADDITIONAL GUSTINESS IS LIKELY (20-25 KTS) WITH
VFR EXPECTED (ALTHOUGH THERE WILL BE SOME PERIODS OF MID LEVEL
CEILINGS).
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
TONIGHT, A STRENGTHENING LOW-LEVEL JET WILL MOVE OVER THE WIDER
WATERS, WITH ANOTHER PERIOD OF SCA GUSTS MOST LIKELY OVER THESE
WIDER WATERS THROUGH SATURDAY MORNING. SCAS ARE IN EFFECT
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, ALTHOUGH
SOME OCCASIONAL GUSTS TO 20 KT COULD OCCUR.
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, WITH ONLY A FEW HUNDREDTHS OF AN INCH OF RAIN FALLING
ACROSS NORTHERN AREAS 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 ANZ531>534-
537-540-541-543.
SYNOPSIS...DHOF
NEAR TERM...ADS
SHORT TERM...DHOF/CJL
LONG TERM...KJP
AVIATION...ADS/DHOF/CJL/KJP
MARINE...ADS/DHOF/CJL/KJP
FIRE WEATHER...CJL
TIDES/COASTAL FLOODING...CJL
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