355
FXUS61 KLWX 021920
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
220 PM EST MON FEB 2 2026
WHAT HAS CHANGED
A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR AREAS WEST OF THE
ALLEGHENY FRONT FOR TUESDAY AFTERNOON AND EVENING. GUIDANCE
CONTINUES TO WAVER ON THE AXIS OF LIGHT SNOW EAST OF THE
APPALACHIANS TUESDAY NIGHT. CONFIDENCE REMAINS IN A REINFORCING
ROUND OF ARCTIC AIR THIS WEEKEND.
KEY MESSAGES
- 1) A CLIPPER-LIKE SYSTEM WILL BRING VERY LIGHT SNOW TUESDAY
EVENING.
- 2) ANOTHER ARCTIC FRONT ARRIVES FRIDAY BRINGING ADDITIONAL
CHANCES FOR SNOW, FOLLOWED BY BITTER COLD ARCTIC AIR.
DISCUSSION
KEY MESSAGE 1...A CLIPPER-LIKE SYSTEM WILL BRING VERY LIGHT
SNOW TUESDAY EVENING.
MID AND HIGH CLOUDS WILL INCREASE FROM THE WEST THROUGH THIS
EVENING IN ASSOCIATION WITH 850-700 HPA WAA. A BAND OF LIGHT
SNOW SHOWERS WILL ACCOMPANY THIS WAVE AS IT INTERSECTS THE
APPALACHIANS TONIGHT, BUT ANY MEAGER MOISTURE SHOULD BE WRUNG
OUT AS IT CROSSES THE MOUNTAINS. THEREFORE, IT IS EXPECTED TO
STAY DRY EAST OF THE MOUNTAINS DESPITE AN INCREASE IN CLOUDS.
AS AN UPPER-LEVEL LOW DIVES ACROSS THE SAINT LAWRENCE RIVER
VALLEY ON TUESDAY, A SEPARATE STRUNG OUT VORT MAX WILL PIVOT
EAST FROM THE OHIO RIVER VALLEY. A WEAK SURFACE LOW WILL DEVELOP
IN RESPONSE, TRACKING TO OUR SOUTH THROUGH TUESDAY NIGHT.
AT THE MOMENT GUIDANCE IS SPLIT ON THE EXACT TRACK OF THE LOW,
AND WHERE THE AXIS OF HIGHEST (THOUGH STILL LIGHT) QPF WILL BE.
THERE APPEAR TO BE TWO CAMPS: (1) AN AXIS OF A COATING TO AN
INCH OR TWO OF SNOW BETWEEN I-66 AND I-70, AND (2) A LIGHT
COATING OF SNOW CLOSER TO I-64.
GIVEN SOMEWHAT MARGINAL BOUNDARY LAYER TEMPS LEADING INTO THE
EVENT (APPROACHING 40 TUESDAY AFTERNOON FOR MANY), THE FAST-
MOVING NATURE OF THE SYSTEM, AND THE LINGERING SPREAD IN
GUIDANCE WITH MODEST QPF AMOUNTS, HAVE HELD OFF ON ANY
ADVISORIES EAST OF THE APPALACHIANS WITH THIS CYCLE. IT IS
POSSIBLE THAT A LOCALLY STEADIER BAND OF SNOW DEVELOPS WHICH
COULD PROMPT A TARGETED ADVISORY IN SUBSEQUENT CYCLES.
IT IS ALSO WORTH NOTING THAT MANY MEMBERS OF HI-RES GUIDANCE AND
THE LATEST CYCLE OF NBM SHOW SOME LIGHT FREEZING RAIN POTENTIAL
ACROSS THE CENTRAL VA PIEDMONT. WITHOUT A CLASSIC "WARM NOSE"
ALOFT, HAVE NOT INCLUDED THIS IN THE FORECAST, BUT COULD STILL
SEE SOME RE-FREEZING GIVEN VERY COLD SURFACE/GROUND TEMPS.
TO THE WEST, THERE IS A BIT HIGHER CONFIDENCE WEST OF THE
ALLEGHENY FRONT THAT A FEW INCHES OF SNOW WILL FALL LEADING UP
TO AND THROUGH THE TUESDAY EVENING COMMUTE. THEREFORE, A WINTER
WEATHER ADVISORY HAS BEEN HOISTED FOR TUESDAY AFTERNOON/EVENING.
KEY MESSAGE 2...ANOTHER ARCTIC FRONT ARRIVES FRIDAY BRINGING ADDITIONAL
CHANCES FOR SNOW, FOLLOWED BY BITTER COLD ARCTIC AIR.
AN ARCTIC FRONT PUSHING ACROSS THE REGION FRIDAY NIGHT INTO
SATURDAY WILL YIELD NOTICEABLY COLDER TEMPERATURES THIS WEEKEND.
IN THE WAKE OF THE FRONT, AN ARCTIC AIR MASS MOVES OVERHEAD AS
SURFACE HIGH PRESSURE BUILDS IN FROM NORTH OF THE GREAT LAKES.
WHILE HIGH TEMPERATURES ON FRIDAY WILL RANGE FROM THE 30S TO MID
40S (20S MTNS), TEMPERATURES ON SATURDAY WILL BE ABOUT 15
DEGREES COLDER WITH HIGHS IN THE TEENS TO 20S FOR MOST.
THE COLD TEMPERATURES WILL BE ACCOMPANIED BY BLUSTERY NORTHWEST
WINDS AND POTENTIAL DANGEROUS WIND CHILLS THIS WEEKEND.
WITH THE FRONTAL PASSAGE ON FRIDAY, SNOW CHANCES RETURN TO THE
FORECAST AREA. HIGHEST CONFIDENCE FOR ACCUMULATING SNOW REMAINS IN
THE ALLEGHENIES, WHERE AN ENHANCED WINTER STORM THREAT CONTINUES.
HERE, SNOW CHANCES RANGE FROM 70-80 PERCENT WITH TRAVEL
DISRUPTIONS POSSIBLE. ELSEWHERE, PRECIPITATION CHANCES RANGE
FROM 10 TO 15 PERCENT IN THE SOUTHERN PORTIONS OF THE FORECAST
AREA (SOUTH OF BETTER FORCING) TO 20 TO 40 PERCENT IN THE
NORTHERN PORTIONS (CLOSER TO THE UPPER SUPPORT). IN THE
ALLEGHENIES WHERE ACCUMULATING SNOW IS LIKELY, GUSTY NORTHWEST
WINDS WILL MAKE BLOWING SNOW POSSIBLE.
AVIATION /18Z MONDAY THROUGH SATURDAY/
VFR IS EXPECTED AT THE TAF SITES THROUGH AT LEAST MIDDAY
TUESDAY. SOME OF THE QUICKER GUIDANCE (HRRR) BRINGS SNOW INTO
THE AREA 20Z-24Z TUESDAY. OTHERWISE, IT LOOKS LIKE ANY SNOW AND
RESTRICTIONS SHOULD GENERALLY HOLD OFF UNTIL AFTER 00Z TUESDAY.
NW WINDS WILL BECOME LIGHT THIS EVENING, THEN TURN TO S TONIGHT.
THERE IS UNCERTAINTY IN EXACTLY WHERE A BAND OF PRECIP SETS UP
TUESDAY EVENING. HOWEVER, THERE IS POTENTIAL FOR A SEVERAL HOUR
PERIOD OF IFR CONDITIONS AND LIGHT SNOWFALL ACCUMULATION. WINDS
WILL TURN N HEADING INTO WEDNESDAY AS VFR RETURNS.
NORTHWEST WINDS ON THURSDAY REMAIN LIGHT, BLOWING 5 TO 10 KNOTS
BEFORE BECOMING LIGHT OVERNIGHT. WINDS SHIFT TO SOUTHWEST FRIDAY
MORNING BEFORE SHIFTING TO NORTHWESTERLY IN THE AFTERNOON AS A COLD
FRONT PUSHES ACROSS THE TERMINALS. WINDS INCREASE BEHIND THE FRONT,
GUSTING UP TO 30 KNOTS FRIDAY NIGHT. DRY CONDITIONS ARE EXPECTED
ON THURSDAY, ALTHOUGH A SLIGHT CHANCE TO A CHANCE OF SNOW ON
FRIDAY MAY LEAD TO BRIEF PERIODS OF SUB-VFR CONDITIONS.
MARINE
NORTHWEST WINDS WILL SUBSIDE HEADING INTO THIS EVENING, THEN
BECOME LIGHT OUT OF THE SOUTH TONIGHT INTO TUESDAY. WINDS WILL
SHIFT BACK TO THE NORTHWEST AND MAY PROMPT SCAS IN THE WAKE OF
WEAK LOW PRESSURE WEDNESDAY. THIS WEAK AREA OF LOW PRESSURE MAY
BRING A PERIOD OF LIGHT SNOW TO THE WATERS TUESDAY NIGHT.
NORTHWEST WINDS ON THURSDAY REMAIN BELOW SCA CRITERIA IN THE MORNING
BEFORE BRIEFLY GUSTING 15 TO 30 KNOTS OVER THE WATERS IN THE
AFTERNOON. SMALL CRAFT ADVISORIES ARE LIKELY ESPECIALLY ACROSS
THE SOUTHERN PORTIONS OF THE CHESAPEAKE BAY THURSDAY AFTERNOON.
ON FRIDAY, WINDS SHIFT TO SOUTHERLY IN THE MORNING AND STAY
BELOW SCA CRITERIA THROUGH THE AFTERNOON. WINDS INCREASE AS A
COLD FRONT PUSHED ACROSS THE WATERS WITH SCA CRITERIA WINDS
EXPECTED OUT OF THE NORTHWEST FRIDAY NIGHT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...WINTER WEATHER ADVISORY FROM NOON TUESDAY TO MIDNIGHT EST
TUESDAY NIGHT FOR MDZ509.
VA...NONE.
WV...WINTER WEATHER ADVISORY FROM NOON TUESDAY TO MIDNIGHT EST
TUESDAY NIGHT FOR WVZ501-505.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ530>543.
DISCUSSION...AVS/DHOF
AVIATION...AVS/DHOF
MARINE...AVS/DHOF
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