164
FXUS61 KLWX 180837
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
337 AM EST THU DEC 18 2025
SYNOPSIS
MILDER TEMPERATURES CONTINUE TODAY AS HIGH PRESSURE REMAINS OFF
THE EAST COAST. HOWEVER, A STRONG COLD FRONT WILL PUSH THROUGH
LATE THIS EVENING INTO FRIDAY MORNING, BRINGING THE NEXT CHANCE
FOR PRECIPITATION. A FEW HEAVIER SHOWERS CAN BE EXPECTED EARLY
FRIDAY MORNING ALONG THE ACTUAL BOUNDARY, FOLLOWED BY COOLER
TEMPERATURES AND STRONG WINDS. BRIEF HIGH PRESSURE RETURNS THIS
WEEKEND, FOLLOWED BY A DRY FRONTAL PASSAGE SUNDAY AFTERNOON.
HIGH PRESSURE EXPECTED INTO EARLY NEXT WEEK.
NEAR TERM /THROUGH FRIDAY/
HIGH PRESSURE WILL LINGER OVERHEAD THIS MORNING INTO THE EARLY
AFTERNOON, LEADING TO A DRY AND PARTLY SUNNY START TO THE DAY.
MILD TEMPERATURES, FOR MID DECEMBER, CAN BE EXPECTED THIS
AFTERNOON WITH HIGHS REACHING THE 40S FOR MOST (40S IN THE
MOUNTAINS).
HIGH PRESSURE WILL MOVE EAST THROUGH THIS AFTERNOON, WHICH WILL
PUSH A WARM FRONT THROUGH THE REGION LATE THIS AFTERNOON INTO
THIS EVENING. DURING THE SAME TIME THAT THIS WARM FRONT IS
PUSHING NORTH, A POTENT UPPER-LEVEL LOW PRESSURE SYSTEM WILL BE
SHOVING EASTWARD ACROSS THE LOWER GREAT LAKES AND OHIO VALLEY.
ADDITIONAL WARMTH AND MOISTURE WILL ALSO BE STREAMING NORTHWARD
AHEAD OF THE MAIN LOW PRESSURE SYSTEM AND JUST BEHIND THE
ADVANCING WARM FRONT. SOME PRE-WARM FRONTAL RAIN SHOWERS ARE
POSSIBLE THURSDAY AFTERNOON, BUT MOST LIKELY SHOWERS WOULD BE
MORE PRONE TO DEVELOP BEHIND THE WARM FRONT AND AHEAD OF THE
APPROACHING AFFILIATED COLD FRONT LATE THURSDAY EVENING.
DURING THE LATE THURSDAY EVENING AND OVERNIGHT INTO EARLY
FRIDAY MORNING, SHOWERS ARE EXPECTED TO DEVELOP AHEAD OF A
POWERFUL COLD FRONT. THIS WILL THEN BE FOLLOWED BY A LINE OF
GUSTY SHOWERS AND PERHAPS A FEW THUNDERSTORMS ACCOMPANYING THE
FRONT ITSELF EARLY ON FRIDAY MORNING. OUTSIDE OF THE SQUALL
LINE, COULD SEE SOME MODERATE SHOWERS EMBEDDED THROUGH THE
OVERNIGHT HOURS. ANY OF THESE COULD BRING DOWN SOME 30 MPH WIND
GUSTS, GIVEN A STOUT WIND FIELD ALOFT WITH 60-70 KTS OF LOW-MID
LEVEL FLOW. DON'T SEE MUCH MORE THAN THAT GETTING DOWN THOUGH,
OWING TO A STOUT INVERSION AT THE SURFACE.
AS FOR THE SQUALL LINE EARLY FRIDAY MORNING, THERE ARE A LOT OF
FACTORS AT PLAY THAT LEND AT LEAST SOME LEVEL OF CONCERN IN
TERMS OF A LOW-END SEVERE WEATHER THREAT. FIRST OFF, THERE WILL
BE PLENTY OF WIND SHEAR TO WORK WITH, AS MENTIONED BEFORE. A
POWERFUL, NEGATIVELY-TILTED, UPPER-LEVEL TROUGH WILL SWING
THROUGH THE REGION EARLY FRIDAY. THIS WILL BE ACCOMPANIED BY A
60-70 KT LLJ. GUIDANCE HAS TRENDED A BIT SLOWER AND DEEPER WITH
THIS TROUGH OVER THE LAST FEW CYCLES.
IN SHORT, DEEP-LAYER SHEAR VALUES IN EXCESS OF 60 KNOTS ARE
FORECAST, WITH IMPRESSIVE CURVED HODOGRAPHS YIELDING LOW-LEVEL
SRH VALUES IN THE 300-400 M2/S2 RANGE. HOWEVER, A KEY COMPONENT
FOR SEVERE WEATHER IS INSTABILITY, AND THIS IS GOING TO BE HARD
TO COME BY GIVEN THE TIME OF DAY THIS FRONT ROLLS THROUGH. LOW-
LEVEL PROFILES SUGGEST LOW-TOPPED CONVECTION OCCURRING IN AN
ENVIRONMENT WITH ISOTHERMAL TO MOIST ADIABATIC LAPSE RATES IN
THE LOWEST SEVERAL THOUSAND FEET, WITH AN INVERSION AROUND 5-6
KFT. BELOW THIS INVERSION, 35-45 KTS OF WIND EXISTS; ABOVE IT,
50-60 KTS. THE MOST LIKELY SCENARIO IS THAT A LINE OF HEAVY
SHOWERS ALONG THE ACTUAL FRONT WILL BRING SOME GUSTY WINDS DOWN
WITH IT. THIS SEEMS REASONABLE GIVEN THE AMOUNT OF LOW-LEVEL
WINDS AT PLAY HERE. HOWEVER, THE MAGNITUDE IS GOING TO BE
GREATLY HINDERED BY A VERY STEEP INVERSION AT THE SURFACE UNTIL
PERHAPS RIGHT WITH FROPA. WHILE YOU CAN PUNCH SOME WINDS
THROUGH THE INVERSION GIVEN STRONG ENOUGH CONVECTION, VERY
RARELY DO YOU GET ALL OF THAT WIND DOWN. FOR THAT REASON, GUSTS
OF 30-40 MPH SEEM MOST LIKELY, WITH SLIGHTLY HIGHER NOT OUT OF
THE QUESTION, ALBEIT PRETTY ISOLATED IN NATURE (AND PERHAPS
ENHANCED OVER HIGHER TERRAIN).
IF THERE WERE A SPOT THAT IS SLIGHTLY MORE FAVORED, THAT WOULD
BE ACROSS SOUTHERN MD. AS IS OFTEN THE CASE, THIS AREA WILL SEE
HIGHER DEW POINTS THAN AREAS NORTH AND WEST. THIS WOULD BE THE
AREA WHERE THE HIGHEST THUNDERSTORM THREAT WOULD BE, ALBEIT
STILL VERY SMALL. IT IS HERE THAT THERE IS SOME INDICATION OF A
LOW- END TORNADO THREAT, BUT AGAIN THIS WILL BE VERY
CONDITIONAL ON THE FACT THAT SOME INSTABILITY IS ABLE TO
DEVELOP. A FEW HI- RES MODELS DO HAVE SOME CAPE IN THAT REGION,
BUT STILL THINKING IT WILL JUST NOT QUITE BE ENOUGH TO SPIN UP A
TORNADO. AT ANY RATE, IT CAN'T BE COMPLETELY RULED OUT, SO IT
IS ALWAYS A GOOD IDEA TO HAVE A WAY TO GET WARNINGS OVERNIGHT,
SHOULD WE HAVE TO ISSUE ANY.
BEHIND THE COLD FRONT, BLUSTERY CONDITIONS RETURN FOR FRIDAY
AFTERNOON IN STRONG WEST TO WEST-NORTHWEST WINDS. WINDS COULD
GUST 40 TO 50 MPH FOR MOST, ESPECIALLY ALONG/NORTH OF THE
I-70 CORRIDOR. SOME ISOLATED WIND DAMAGE IS POSSIBLE IN THESE
AREAS. WIND GUSTS OF 45 TO PERHAPS 60 MPH CAN BE EXPECTED OVER
THE HIGHER ELEVATIONS DURING THIS TIME. HIGH WIND WATCHES AND
WIND ADVISORIES HAVE BEEN ISSUED FOR MANY AREAS AS A RESULT.
ELSEWHERE, WIND GUSTS ARE STILL EXPECTED TO BE 30-40 MPH, SO
STILL ENOUGH TO BLOW AROUND UNSECURED ITEMS AND WREAK SOME
HAVOC.
SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/
HIGH PRESSURE BUILDS OVERHEAD FRIDAY NIGHT BEFORE QUICKLY MOVING
OFFSHORE THROUGHOUT THE DAY ON SATURDAY. THIS IS DUE TO A VERY
PROGRESSIVE QUASI-ZONAL FLOW ALOFT. WINDS PICK UP SATURDAY
AFTERNOON OUT OF THE SW AHEAD OF A QUICK-MOVING FRONTAL
BOUNDARY, SET TO SWING THROUGH THE REGION ON SUNDAY. IN THE WAKE
OF FRIDAY'S COLD FRONT, STILL EXPECT HIGHS TO ONLY REACH THE MID
40S, BUT THAT IS AROUND NORMAL FOR MID-DECEMBER.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
A DRY COLD FRONT IS EXPECTED TO WORK ACROSS THE REGION ON SUNDAY.
TEMPERATURES WILL BE A FEW DEGREES ABOVE AVERAGE WITH HIGHS IN THE
UPPER 40S TO MIDDLE 50S.
CHILLY HIGH PRESSURE WILL BUILD IN MONDAY BEFORE MOVING EAST MONDAY
NIGHT. TEMPERATURES WILL DROP TO BELOW AVERAGE STATUS WITH HIGHS
BARELY MAKING IT TO 40 DEGREES ALONG AND NORTH OF I-66, WHILE
TEMPERATURES TO THE SOUTH MAY STRUGGLE TO GET TO THE MIDDLE 40S.
THE HIGH WILL MOVE TO THE EAST THROUGH THE DAY TUESDAY INTO TUESDAY
NIGHT. THIS WILL ALLOW FOR A DISTURBANCE APPROACHING FROM THE WEST
TO BRING A SLIGHT CHANCE OR CHANCE OF LIGHT RAIN OR LIGHT SNOW TO
PARTS OF THE REGION. TEMPERATURES WILL BE CLOSER TO AVERAGE WITH
HIGHS IN THE 40S FOR MOST.
THROUGH THE DAY ON WEDNESDAY, THE AFOREMENTIONED COLD FRONT WILL
PUSH SOUTH AND EASTWARD. HIGH PRESSURE WILL BUILD ON THE NORTH SIDE
OF THE FRONT AND BRING SLIGHTLY COOLER AND DRIER AIR INTO THE
REGION.
AVIATION /08Z THURSDAY THROUGH MONDAY/
GRADUAL WARMING TEMPERATURES WITH A SOUTHERLY WIND AHEAD OF A
POWERFUL FRONT SET TO PUSH THROUGH LATE TONIGHT INTO FRIDAY
MORNING. VFR CONDITIONS CAN BE EXPECTED FOR MUCH OF TODAY, WITH
LIGHT WINDS SHIFTING OUT OF THE SOUTH.
SUB-VFR CONDITIONS ARE POSSIBLE LATE THIS AFTERNOON AS A FRONT
APPROACHES THE TERMINALS WITH RESTRICTIONS LIKELY DURING
PRECIPITATION OVERNIGHT. SOUTHERLY WINDS GUST 15 TO 25 KNOTS
THURSDAY AFTERNOON AND INTO THE OVERNIGHT AHEAD OF THE FRONT.
SOME CONVECTION IS POSSIBLE OVERNIGHT, BUT MORE LIKELY IN THE
FORM OF A BRIEF HEAVY DOWNPOUR, ESPECIALLY ALONG THE ACTUAL
FRONT EARLY FRIDAY MORNING. THIS COULD ALSO BE ACCOMPANIED BY A
SURGE OF 30-40 KNOT WINDS ALONG THE MAIN LINE.
VFR CONDITIONS AND GUSTY WINDS ARE EXPECTED ACROSS ALL TERMINALS ON
FRIDAY IN THE WAKE OF THE COLD FRONT. WIND GUSTS WILL BE HIGHER
UP TOWARDS MRB, BWI, AND MTN, WHERE 40 KT WINDS CAN BE
EXPECTED. ELSEWHERE, GENERALLY AROUND 25-30 KTS FRIDAY
AFTERNOON.
WINDS DIMINISH QUICKLY FRIDAY EVENING BEFORE BECOMING LIGHT
OVERNIGHT. LIGHT SOUTHERLY WINDS ON SATURDAY MORNING PICK UP
QUICKLY DURING THE AFTERNOON, BUT THEN BECOME LIGHT AGAIN OVERNIGHT.
VFR CONDITIONS SUNDAY THROUGH MONDAY NIGHT. WINDS SOUTHWEST BECOMING
NORTHWEST 5 TO 10 KNOTS SUNDAY AND SUNDAY NIGHT. WINDS ON MONDAY
WILL BE MAINLY NORTHWEST THEN BECOME LIGHT AND VARIABLE MONDAY
NIGHT.
MARINE
WINDS SHIFT EAST THIS MORNING BEFORE INCREASING AND TURNING OUT
OF THE SOUTH THIS AFTERNOON.
GALE WARNINGS HAVE BEEN ISSUED STARTING THIS EVENING. THIS WAS
DONE AS A RESULT OF TWO KEY FACTORS. FIRST OFF, WINDS RAPIDLY
INCREASE OVERNIGHT OUT OF THE SOUTH AHEAD OF A POWERFUL COLD
FRONT. WHILE WIND LIKELY STAY AROUND 20-30 KNOTS FOR MUCH OF THE
NIGHT, ANY EMBEDDED HEAVIER SHOWERS COULD BRING DOWN SOME GALE-
FORCE GUSTS AT ANY POINT OVERNIGHT. THE SECOND, AND MORE
SUBSTANTIAL THREAT COMES IN TWO WAVES. WAVE NUMBER ONE WILL BE
THE COLD FRONT ITSELF, WHICH WILL BRING A SQUALL LINE ACROSS THE
WATERS, WHICH COULD BRING DOWN SOME BRIEF 40 KT GUSTS. THIS WILL
BE FOLLOWED BY A BRIEF LULL, BUT ALSO A WIND SHIFT OUT OF THE W
TO WNW. A SURGE OF WINDS ARRIVES LATER FRIDAY MORNING INTO THE
AFTERNOON, WHICH WILL LIKELY BRING GALE-FORCE WINDS TO MOST OF
THE WATERS. HIGHEST GUSTS WILL BE IN THE CHESAPEAKE, NORTH OF
NORTH BEACH.
AS HIGH PRESSURE BUILDS OVER THE AREA, WINDS DIMINISH FRIDAY
NIGHT, BECOMING LIGHT BY SATURDAY MORNING.
SMALL CRAFT ADVISORIES ARE POSSIBLE BOTH SATURDAY AND SUNDAY
AFTERNOON. SOUTHERLY WINDS ON SATURDAY SHIFT TO NORTHWESTERLY ON
SUNDAY, GUSTING 15 TO 20 KNOTS EACH AFTERNOON.
NO MARINE HAZARDS EXPECTED MONDAY, WITH NW AOB 15 KTS.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...GALE WARNING FROM 6 PM THIS EVENING TO 1 AM EST SATURDAY FOR
MDZ008.
WIND ADVISORY FROM NOON TO 7 PM EST FRIDAY FOR MDZ003>006-008-
011-505>508.
HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
MDZ501-510.
WIND ADVISORY FROM 6 AM TO 7 PM EST FRIDAY FOR MDZ502-509.
VA...WIND ADVISORY FROM NOON TO 7 PM EST FRIDAY FOR VAZ028.
WIND ADVISORY FROM 6 AM TO 7 PM EST FRIDAY FOR VAZ025-503-504-
507-508.
WV...WIND ADVISORY FROM NOON TO 7 PM EST FRIDAY FOR WVZ050>053-055.
HIGH WIND WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
WVZ501-503-505.
WIND ADVISORY FROM 6 AM TO 7 PM EST FRIDAY FOR WVZ502-504-506.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 1 AM EST SATURDAY FOR
ANZ530>543.
WIND ADVISORY FROM NOON TO 7 PM EST FRIDAY FOR ANZ530.
SYNOPSIS...CJL
NEAR TERM...DHOF/CJL
SHORT TERM...DHOF/CJL
LONG TERM...KLW
AVIATION...KLW/DHOF/CJL
MARINE...KLW/DHOF/CJL
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