246
FXUS61 KLWX 271416
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
916 AM EST THU NOV 27 2025
SYNOPSIS
LOW PRESSURE WILL LINGER OVER SOUTHEASTERN CANADA WHILE HIGH
PRESSURE BUILDS ACROSS THE MIDWEST AND TENNESSEE VALLEY THROUGH
FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD SATURDAY, THEN MOVE
OFFSHORE SUNDAY INTO EARLY NEXT WEEK AS THE NEXT SYSTEM
APPROACHES FROM THE WEST.
NEAR TERM /THROUGH TONIGHT/
WINDS HAVE REALLY STARTED TO DECREASE IN THE MOUNTAINS, SO
PLANNING ON LETTING THE WIND ADVISORY DROP LATER THIS MORNING.
MID TO HIGH LEVEL CLOUDS HAVE OVERSPREAD THE AREA AND SHOULD
LINGER THROUGH MOST OF THE DAY AS A POWERFUL JET STREAK
ADVANCES AHEAD OF A DIGGING TROUGH OVER THE EASTERN GREAT LAKES.
HIGH TEMPS ONLY REACH THE LOW TO MID 40S ACROSS THE AREA.
COMBINED WITH GUSTY WINDS WILL KEEP WIND CHILLS IN THE 30S FOR
MOST OF THE DAY.
TONIGHT...IMPROVING LOW-LEVEL CYCLONIC CURVATURE AND FALLING
HEIGHTS ASSOCIATED WITH APPROACH OF STRONG SHORTWAVE-TROUGH
ROUNDING THE BASE OF EASTERN GREAT LKS TROUGH WILL CREATE A
FAVORABLE PERIOD OF CONVECTIVE SNOW SHOWERS THIS EVENING.
STEEPENING LOW-LEVEL LAPSE RATES AND RISING INVERSION HEIGHTS
WILL SUPPORT CONVECTIVE SNOWFALL RATES. GIVEN STRONG FORCING,
DECREASING STABILITY, AND VERY COLD TEMPERATURES/HIGH SLRS, A
PERIOD OF SNOW ACCUMULATION IS EXPECTED TONIGHT FOR THE
ALLEGHENY MOUNTAINS.
BOTH THE NBM AND NBM 90TH QPF LOOK WOEFULLY UNDERDONE IN THE
MOUNTAINS AND HAVE FOLLOWED WPC'S QPF GUIDANCE. THIS YIELDS SNOW
TOTALS OF 3-4 INCHES ACROSS WESTERN GRANT AND WESTERN PENDLETON
COUNTIES, ENOUGH TO MEET THE CRITERIA FOR A WINTER WX ADVISORY
FOR THOSE ZONES. THE TROUGH AXIS SHIFTS EAST OF THE AREA AFTER
15Z FRI LOWERING INVERSION HEIGHTS DECREASING SNOWFALL RATES AND
PRECIP COVERAGE. GIVEN TIGHT PRESSURE GRADIENT, A VERY BLUSTERY
DAY IS EXPECTED WITH FREQ GUSTS TO 35-40 MPH. THIS WHEN
COMBINED WITH HIGH TEMPS AROUND 40F YIELDS WIND CHILL VALUES
AROUND FREEZING DURING THE WARMEST PART OF THE DAY FOR AREAS
EAST OF THE BLUE RIDGE MOUNTAINS AND WELL BELOW FREEZING FOR
AREAS WEST OF THERE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
HIGH PRESSURE BUILDS IN FRI NIGHT, SETTLING OVERHEAD BY SATURDAY
BEFORE RETREATING SATURDAY NIGHT. VERY COLD FRI NIGHT UNDER
CLEAR SKIES AND LIGHT WINDS.
NEXT POTENT SHORTWAVE-TROUGH AND ASSOCIATED AREA OF LOW PRESSURE
CROSSING THE CHICAGO AREA SATURDAY NIGHT WILL BRING INCREASING
CLOUDS TO THE AREA BEGINNING SATURDAY NIGHT. FOLLOWING OOZ EPS
MEANS AND WPC GUIDANCE, PRECIP ARRIVES BEFORE 12Z SUNDAY TO
AREAS WEST OF I-81 WITH VERY LIGHT SNOW ACCUMULATIONS POSSIBLE
BY 12Z SUN AND A LIGHT WINTRY MIX TO AREAS OF THE CENTRAL BLUE
RIDGE MOUNTAINS AND CENTRAL SHENANDOAH RIVER VALLEY. SINCE THIS
IS JUST RIGHT AT THE 72-HR TIME FRAME, NO SNOW OR ICE TOTALS
WILL BE PROVIDED YET.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
AS HIGH PRESSURE RETREATS OFFSHORE, A SHORTWAVE AND ATTENDANT AREA
OF LOW PRESSURE WILL TRACK FROM THE CENTRAL PLAINS NORTHEASTWARD
TOWARD THE GREAT LAKES. AS LARGE SCALE ASCENT INCREASES,
PRECIPITATION WILL BREAK OUT ACROSS THE AREA ON SUNDAY. VARIOUS
SOURCES OF GUIDANCE DIFFER WITH RESPECT TO HOW QUICKLY PRECIPITATION
WILL BREAK OUT. IF PRECIPITATION WERE TO BREAK OUT EARLY IN THE DAY
BEFORE DAYTIME HEATING WERE TO OCCUR, IT COULD START AS A BRIEF
PERIOD OF FREEZING RAIN. AT THE MOMENT, THIS FREEZING RAIN SCENARIO
STILL APPEARS TO HAVE A LOW PROBABILITY OF OCCURRENCE, AND WOULD
LIKELY BE LIMITED TO LOCATIONS ALONG AND WEST OF US-15 IF IT WERE TO
OCCUR. HOWEVER, IT BEARS WATCHING AS WE MOVE CLOSER TO THE EVENT,
ESPECIALLY SINCE SUNDAY IS ONE OF THE BUSIER TRAVEL DAYS OF THE
YEAR. ELSEWHERE, JUST RAIN IS EXPECTED, WITH TEMPERATURES CLIMBING
INTO THE 40S. TOTAL RAINFALL AMOUNTS LOOK TO BE ON THE LIGHTER SIDE,
WITH A GENERAL TENTH TO A QUARTER OF AN INCH FOR MOST. RAIN WILL
MOVE OUT OF THE AREA BY LATE SUNDAY NIGHT.
QUIETER CONDITIONS ARE EXPECTED ON MONDAY AS SUNDAY'S SYSTEM PASSES
OFF TO OUR NORTHEAST. MOSTLY CLOUDY SKIES ARE EXPECTED, WITH HIGHS
GENERALLY IN THE 40S (30S MOUNTAINS).
FORECAST CONFIDENCE REMAINS VERY LOW TUESDAY INTO WEDNESDAY. ON THE
SYNOPTIC SCALE, A SHORTWAVE EMBEDDED WITHIN A MUCH BROADER LONGWAVE
TROUGH ENCOMPASSING MUCH OF THE CONUS IS EXPECTED TO LIFT
NORTHEASTWARD OUT OF THE BASE OF THE LONGWAVE TROUGH AND INTERACT
WITH WHAT SHOULD BE A SHARP BAROCLINIC ZONE IN PLACE ALONG THE EAST
COAST. VARIOUS SOURCES OF BOTH DETERMINISTIC AND ENSEMBLE GUIDANCE
HAVE SHOWN A LARGE AMOUNT OF SPREAD WITH RESPECT TO WHAT WILL ENSUE
WITH THIS SYSTEM. SOME SOLUTIONS HAVE SHOWN LARGE PRECIPITATION
TOTALS, WHILE OTHERS HAVE SHOWN LITTLE PRECIPITATION AT ALL. SOME
SHOW SNOW, SOME SHOW A WINTRY MIX, AND OTHERS SHOW PLAIN RAIN. AS IS
TYPICAL, TEMPERATURES LOOK TO BE COLDER THE FURTHER NORTH AND WEST
ONE GOES, SO THOSE LOCATIONS HAVE A GREATER CHANCE TO EXPERIENCE
WINTRY PRECIPITATION IF IT WERE TO OCCUR. IT'S STILL TOO EARLY TO
GET INTO DETAILS AT THIS POINT, BUT THIS SYSTEM WILL BE ONE TO
MONITOR OVER THE NEXT SEVERAL DAYS, AS IT HAS AT LEAST A CHANCE TO
BRING PORTIONS OF THE AREA THEIR FIRST WINTRY PRECIPITATION EVENT OF
THE SEASON.
AVIATION /14Z THURSDAY THROUGH MONDAY/
BLUSTERY WNW WINDS ARE EXPECTED TODAY WITH GUSTS UP TO 20-25
KT, STRONGER ON FRI WITH GUSTS UP TO 30 KT. WINDS DIMINISH FRI
NIGHT AS HIGH PRESSURE BUILDS IN.
SUB-VFR CONDITIONS AND RAIN APPEAR POSSIBLE AT TIMES ON SUNDAY.
WINDS WILL BE OUT OF THE SOUTH AT AROUND 5-10 KNOTS. WINDS WILL
SHIFT TO THE WEST, NORTHWEST, THEN NORTH SUNDAY NIGHT THROUGH MONDAY
NIGHT WITH VFR EXPECTED IN THE WAKE OF LOW PRESSURE.
MARINE
CONTINUED BLUSTERY CONDITIONS ARE EXPECTED THROUGH FRI NIGHT
BEFORE WINDS DIMINISH SATURDAY MORNING. A PERIOD OF GALES IS
STILL POSSIBLE FRI. OTHERWISE, SMALL CRAFT ADVISORIES WILL
PERSIST FOR MOST OF THE WEEKEND.
WINDS WILL TURN OUT OF THE SOUTH ON SUNDAY AND COULD BE NEAR
LOW- END SCA LEVELS WITHIN CHANNELED SOUTHERLY FLOW. MARGINAL
SCA CONDITIONS COULD EVOLVE AS WINDS SHIFT TO THE WEST,
NORTHWEST, AND NORTH SUNDAY NIGHT THROUGH MONDAY NIGHT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR MDZ501-509-510.
VA...WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR VAZ503-504-507-
508.
WV...WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR WVZ501-503-505-
506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>534-
537>543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
536.
SYNOPSIS...LFR
NEAR TERM...KRR/LFR
SHORT TERM...LFR
LONG TERM...DHOF
AVIATION...LFR/DHOF
MARINE...KRR/LFR/DHOF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page