504
FXUS61 KLWX 162041
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
341 PM EST SUN FEB 16 2025
SYNOPSIS
A COLD FRONT WILL PUSH EAST OF THE AREA THIS EVENING. AN
EXPANSIVE ARCTIC HIGH PRESSURE WILL BUILD INTO THE NORTH-CENTRAL
U.S. THIS WEEK. MEANWHILE, AN AREA OF LOW PRESSURE WILL TAKE
SHAPE OVER THE MISSISSIPPI RIVER VALLEY BY MID WEEK, THEN TRACK
TO THE CAROLINAS AND UP OFF THE EAST COAST WEDNESDAY INTO
THURSDAY. HIGH PRESSURE WILL TAKE OVER LATE IN THE WEEK.
NEAR TERM /THROUGH MONDAY/
A CONVECTIVE LINE (INCLUDING THUNDERSTORMS WITH PEA SIZE HAIL)
FORMED AHEAD OF THE COLD FRONT AND POTENT SHORTWAVE ALOFT.
WHILE SOME STRONG GUSTS HAVE BEEN OBSERVED ALONG THE LINE, THE
STRONGEST GUSTS ARE FOLLOWING SHORTLY AFTER IT PASSES AND STRONG
PRESSURE RISES (7MB IN 2HR PER SPC MESOANALYSIS) OCCUR BEHIND
THE FRONT. GUSTS IN THE 45-65 MPH HAVE BEEN OBSERVED SO FAR, AND
EXPECT THIS TREND TO CONTINUE EASTWARD ACROSS THE AREA. HIGH
WIND WARNINGS AND WIND ADVISORIES REMAIN IN EFFECT.
COLD AIR HAS ALREADY MOVED INTO THE APPALACHIANS, RESULTING IN A
CHANGEOVER TO SNOW. THE STRONG FORCING IS RESULTING IN HEAVY
SNOW AND NEAR BLIZZARD CONDITIONS AMONGST THE GUSTY POSTFRONTAL
WINDS. FROUDE NUMBERS ARE RATHER HIGH, ESPECIALLY OVERNIGHT,
INDICATING HIGH INVERSION LEVELS AND A HIGH LIKELIHOOD FOR
SPILLOVER EAST OF THE APPALACHIAN CREST. BLIZZARD WARNINGS AND
WINTER WEATHER ADVISORIES REMAIN IN EFFECT NEAR AND WEST OF THE
ALLEGHENY FRONT FOR THIS REASON, WITH NO APPRECIABLE CHANGE IN
EXPECTATION FROM THE PREVIOUS THINKING. THE HIGH FROUDE NUMBERS
MAY ALLOW FLURRIES OR A SNOW SHOWER OR TWO TO DRIFT EAST TOWARD
THE BLUE RIDGE OVERNIGHT.
AFTER THE INVERSION FINALLY BROKE, TEMPERATURES ROSE INTO THE
MID 50S TO MID 60S FOR MOST OF THE AREA, BUT TEMPERATURES WILL
FALL QUICKLY BEHIND THE FRONT. OVERNIGHT LOWS WILL BE IN THE MID
20S TO LOWER 30S, WITH TEENS IN THE HIGHER ELEVATIONS. SUBZERO
WIND CHILL VALUES ARE LIKELY IN THE HIGHER ELEVATIONS.
UPSLOPE SNOW WILL LINGER INTO MONDAY MORNING ALONG AND WEST OF
THE ALLEGHENY FRONT. FURTHER EAST, FLURRIES MAY CROSS AS FAR
EAST AS THE BLUE RIDGE BEFORE DRY AIR TAKES OVER AND CONDITIONS
DRY OUT. STRONG WINDS CONTINUE, ESPECIALLY OVER THE MOUNTAINS
AND NORTH OF I-66/US-50. NOT SURE IF WINDS QUITE REACH WIND
ADVISORY THRESHOLDS, BUT IT WILL BE GUSTY EITHER WAY. BELOW
NORMAL TEMPERATURES RETURN, WITH HIGHS REACHING THE MID 30S TO
MID 40S (TEENS/20S IN THE HIGHER ELEVATIONS).
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/
STRONG HIGH PRESSURE TO THE NORTHWEST NEVER FULLY BUILDS IN
THROUGH TUESDAY. SO WHILE NOT QUITE AS STRONG, NORTHWEST WINDS
WILL REMAIN ELEVATED, PARTICULARLY DURING THE DAYLIGHT HOURS.
TEMPERATURES WILL REMAIN BELOW NORMAL. PRECIPITATION WITH THE
NEXT SYSTEM WILL BE ON OUR WESTERN DOORSTEP BY LATE TUESDAY
NIGHT.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
BY THE MIDDLE OF THE WEEK, ATTENTION WILL TURN TO A POTENTIAL WINTER
STORM APPROACHING FROM THE SOUTH AND WEST. RECENT TRENDS HAVE BEEN
FOR MORE SEPARATION BETWEEN A SOUTHERN STREAM DISTURBANCE (CURRENTLY
LOCATED OFF THE PACIFIC NORTHWEST COAST), AND A NORTHERN STREAM
DISTURBANCE (PRIMARILY COMPOSED OF A SHORTWAVE CURRENTLY MOVING FROM
EAST TO WEST ALONG THE NORTHERN PERIPHERY OF AN UPPER LOW CURRENTLY
CENTERED OVER MANITOBA AND SASKATCHEWAN). GREATER SPACING BETWEEN
THESE FEATURES WOULD LIKELY RESULT IN LESS INTERACTION, AND LATER
PHASING BETWEEN THESE TWO DISTURBANCES, LEADING TO A MORE SOUTHERN
STORM TRACK. THIS TREND TOWARD A MORE SUPPRESSED, SOUTHERN TRACK
SYSTEM STARTED YESTERDAY, CONTINUED WITH THE 00Z RUNS LAST NIGHT,
AND IS EVEN MORE PREVALENT WITHIN INCOMING 12Z GUIDANCE.
THIS TREND TOWARD A MORE SOUTHERN TRACK IS LEADING TO A TREND DOWN
IN SNOWFALL TOTALS ACROSS MUCH OF THE AREA. WHILE IT STILL APPEARS
LIKELY THAT MOST OF THE AREA WILL SEE AT LEAST SOME SNOWFALL, A
SCENARIO WHERE THE NORTHERN HALF OF THE FORECAST AREA SEES VERY
LITTLE SNOWFALL (NEARLY ALL IN ASSOCIATION WITH THE NORTHERN STREAM
SYSTEM) IS A DISTINCT POSSIBILITY NOW. THAT ISN'T TO SAY THAT THE
THREAT FOR A LARGER STORM HAS GONE AWAY, IT'S JUST THAT
PROBABILITIES FOR THAT OCCURRING HAVE DECREASED GREATLY. AT THE
MOMENT, IT APPEARS AS THOUGH SOUTHERN MARYLAND CURRENTLY STANDS THE
GREATEST CHANCE FOR HIGHER SNOWFALL TOTALS, AS THEY'D BE LOCATED
CLOSER TO THE SOUTHERN STORM TRACK AND EVENTUAL DEEPENING COASTAL
LOW.
WHILE THE TREND HAS BEEN DOWNWARD WITH SNOWFALL TOTALS, THAT DOESN'T
MEAN THAT THERE CAN'T BE FURTHER SHIFTS IN EITHER DIRECTION AS WE
MOVE CLOSER TO THE EVENT. THE PATTERN ACROSS NORTH AMERICA,
AS WELL AS THE NORTH PACIFIC AND NORTH ATLANTIC IS VERY
COMPLEX AT THE MOMENT, WITH NUMEROUS INTERACTIONS BETWEEN
DIFFERENT DISTURBANCES YET TO OCCUR. THIS LENDS ITSELF TO
SOME LINGERING UNCERTAINTY. SYSTEMS WITH LOTS OF CONVECTION
IN THE SOUTHERN STREAM (AS THIS ONE WILL) ALSO COMMONLY TREND
NORTHWARD AT SHORT LEAD TIMES. THE UPPER LEVEL PATTERN TO OUR
NORTHEAST AT THE TIME OF THE SYSTEM WILL LIKELY BE VERY BLOCKED, SO
THAT POTENTIAL FOR A NORTHWARD SHIFT BACK IS SOMEWHAT LIMITED, BUT
STILL EXISTS. SO WHILE THE CLEAR TREND AT THE MOMENT IS VERY MUCH
TOWARD A MORE SOUTHERN TRACK AND LOWER SNOW TOTALS, THERE IS STILL
TIME FOR THINGS TO CHANGE.
IN TERM OF TIMING, IT CURRENTLY LOOKS LIKE THE BULK OF THE SNOW THAT
DOES FALL WILL OCCUR WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT,
WITH SOME LOW END POTENTIAL FOR SOME LIGHTER SNOW LINGERING INTO
THURSDAY MORNING. MODELS ARE IN GOOD AGREEMENT THAT COLDER AIR
WILL FILTER INTO THE AREA IN NORTHWESTERLY FLOW BEHIND THE
DEPARTING SYSTEM. HIGH TEMPERATURES WILL STRUGGLE TO REACH FREEZING
ON THURSDAY, AND THEN DROP BACK INTO THE SINGLE DIGITS AND TEENS
THURSDAY NIGHT. WINDS CHILLS ARE EXPECTED TO BOTTOM OUT IN THE
SINGLE DIGITS ABOVE/BELOW ZERO LATE THURSDAY NIGHT. DRY CONDITIONS
AND CONTINUED BELOW AVERAGE TEMPERATURES ARE EXPECTED FOR FRIDAY AND
SATURDAY. HIGH TEMPERATURES ARE FORECAST TO BE IN THE 30S FOR MOST
(20S MOUNTAINS), WITH LOWS IN THE TEENS TO NEAR 20.
AVIATION /20Z SUNDAY THROUGH FRIDAY/
A STRONG COLD FRONT WILL PUSH EAST OF THE TERMINALS BY 22Z. A
LINE OF CONVECTION FORMED AHEAD OF THE FRONT, ALTHOUGH LIGHTING
OBSERVATIONS HAVE BEEN TRENDING DOWNWARD. BEHIND THE FRONT,
WINDS ARE INCREASING QUICKLY INTO THE 40-50KT RANGE. WINDS
SHOULD TAPER SLIGHTLY THIS EVENING, BUT 35 KT GUSTS SHOULD BE
PERSISTENT (EXCEPT AT CHO) THROUGH MONDAY. AFTER FRONTAL CLOUDS
CLEAR, ONLY SCT TO PERHAPS BKN STRATOCU WILL BE PRESENT THROUGH
MONDAY. A FEW FLURRIES COULD REACH MRB TONIGHT/MONDAY MORNING,
BUT CONFIDENCE IS LOW.
VFR CONDITIONS WILL CONTINUE THROUGH TUESDAY, WITH 20 KT GUSTS
RETURNING DURING THE DAYLIGHT HOURS.
SUB-VFR CONDITIONS APPEAR LIKELY ALONG WITH SNOW WEDNESDAY AFTERNOON
INTO THURSDAY MORNING. IMPROVEMENT BACK TO VFR CONDITIONS IS
EXPECTED BY THURSDAY AFTERNOON. WINDS ARE FORECAST TO BE OUT OF THE
NORTH ON WEDNESDAY, AND THEN NORTHWEST ON THURSDAY.
MARINE
A WIND SHIFT TO THE WEST AND A SHARP INCREASE IN WINDS TO STORM
FORCE ARE LIKELY AS A COLD FRONT CROSSES THE WATERS THROUGH 5
PM. A LIGHTNING STRIKE OR TWO CAN'T BE RULED OUT WITH AN AREA OF
SHOWERS THAT WILL ALSO BE CROSSING. AS THE COLD FRONT MOVES
OFFSHORE, A LARGE AREA OF HIGH PRESSURE WILL DESCEND INTO THE
NORTH-CENTRAL U.S. THE GRADIENT BETWEEN THESE TWO SYSTEMS WILL
LEAD TO ONLY GRADUALLY DIMINISHING WINDS THROUGH TUESDAY (GALES
LINGER INTO MONDAY, SCAS INTO TUESDAY).
SUB-SCA NORTHERLY WINDS ARE EXPECTED ON WEDNESDAY. WINDS WILL SHIFT
TO NORTHWESTERLY LATE WEDNESDAY NIGHT INTO THURSDAY. SCA GUSTS
APPEAR LIKELY DURING THAT TIME.
LWX WATCHES/WARNINGS/ADVISORIES
DC...HIGH WIND WARNING UNTIL 10 PM EST THIS EVENING FOR DCZ001.
MD...HIGH WIND WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ004>006-
008-011-013-014-016>018-503>508.
STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ008.
GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR
MDZ008.
BLIZZARD WARNING UNTIL 3 PM EST MONDAY FOR MDZ001.
HIGH WIND WARNING UNTIL 1 AM EST MONDAY FOR MDZ003.
HIGH WIND WARNING UNTIL NOON EST MONDAY FOR MDZ501-502.
WINTER WEATHER ADVISORY UNTIL 3 PM EST MONDAY FOR MDZ501.
VA...HIGH WIND WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ040-053-
054-501-505-506-526-527.
HIGH WIND WARNING UNTIL 1 AM EST MONDAY FOR VAZ025>031.
HIGH WIND WARNING UNTIL NOON EST MONDAY FOR VAZ503-504-507-508.
WINTER WEATHER ADVISORY UNTIL 3 PM EST MONDAY FOR VAZ503.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ036>039-050-
051-055>057-502.
WV...BLIZZARD WARNING UNTIL 3 PM EST MONDAY FOR WVZ501-505.
HIGH WIND WARNING UNTIL 1 AM EST MONDAY FOR WVZ050>053-055.
HIGH WIND WARNING UNTIL NOON EST MONDAY FOR WVZ502>504-506.
WINTER WEATHER ADVISORY UNTIL 3 PM EST MONDAY FOR WVZ503.
MARINE...HIGH WIND WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ530.
STORM WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ530>543.
GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR
ANZ530>543.
SYNOPSIS...ADS/DHOF
NEAR TERM...ADS/DHOF
SHORT TERM...ADS
LONG TERM...KJP
AVIATION...ADS/DHOF/KJP
MARINE...ADS/DHOF/KJP
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