896
FXUS61 KLWX 181513
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1013 AM EST TUE FEB 18 2025
SYNOPSIS
AN EXPANSIVE ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE
NORTH-CENTRAL U.S. THIS WEEK. MEANWHILE, AN AREA OF LOW PRESSURE
TAKING SHAPE OVER THE MID SOUTH WILL TRACK TO THE CAROLINAS AND OFF
THE EAST COAST WEDNESDAY INTO THURSDAY. HIGH PRESSURE WILL TAKE OVER
LATE IN THE WEEK.
NEAR TERM /THROUGH TONIGHT/
MORNING UPDATE: UPPER-LEVEL CIRRUS, GENERALLY EAST OF THE BLUE
RIDGE MOUNTAINS, STARTING TO GRADUALLY PUSH EAST THIS MORNING.
ALREADY SEEING EVIDENCE OF SOME WAVE CLOUDS OVER THE WESTERN
AREAS, AND THIS IS LIKELY TO EXPAND EASTWARD THROUGH THE
MORNING INTO THIS AFTERNOON AS A MID-LEVEL FRONT SAGS SLOWLY
SOUTHWARD. IT WILL BE A BIT BREEZY TODAY WITH GUSTS OF 15 TO 25
MPH, BUT NOT AS WINDY AS PREVIOUS DAYS.
LATER TONIGHT, CLOUDS WILL INCREASE AND PRECIPITATION WILL
APPROACH WEST-CENTRAL VA AS LOW PRESSURE OVER THE MID SOUTH
TRACKS EASTWARD. MOST PRECIPITATION WILL LIKELY HOLD OFF UNTIL
AROUND OR SHORTLY AFTER DAYBREAK, BUT SOME SNOW IS POSSIBLE
AFTER ABOUT 3-5AM OVER HIGHLAND COUNTY DOWN OVER TO WINTERGREEN.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
MORNING UPDATE: NO CHANGES TO THE SHORT-TERM AT THIS TIME. BUT
MONITORING 12Z MODEL GUIDANCE AS IT COMES IN FOR ANY POTENTIAL
FORECAST TWEAKS AND/OR WINTER HEADLINE DECISIONS.
PREVIOUS DISCUSSION: A REMARKABLY COMPLICATED WINTER WEATHER
EVENT LOOKS TO UNFOLD NEAR AND JUST SOUTH OF OUR LOCAL AREA MID
WEEK. A SOUTHERN STREAM SHORTWAVE AND ASSOCIATED SURFACE LOW
WILL SCOOT BY TO THE SOUTH, PASSING OFFSHORE OF THE CAROLINAS
WEDNESDAY INTO WEDNESDAY NIGHT. MOST PRECIPITATION WITH THIS LOW
WILL STAY SOUTH OF I-66 AND MAINLY NEAR AND SOUTH OF I-64 GIVEN
THE FLATTER AND MORE PROGRESSIVE SOUTHERN TRACK AND ABUNDANT
DRY AIR TO THE NORTH. WEST OF THE BLUE RIDGE INTO THE CENTRAL
SHENANDOAH VALLEY TO HIGHLAND/WESTERN PENDLETON COUNTIES,
CONFIDENCE IS HIGH AND SPREAD IS RELATIVELY LOWER - SO HAVE
ISSUED AN ADVISORY FOR THESE AREAS FOR WEDNESDAY/WEDNESDAY
NIGHT. FURTHER EAST IN CENTRAL VA TO SOUTHERN MD EAST OF THE
BLUE RIDGE, CONFIDENCE DROPS SIGNIFICANTLY, AND THE RANGE OF
POSSIBILITIES INCREASES DRAMATICALLY. FOR EXAMPLE, AT POINT
LOOKOUT THE 00Z NAM HAS A FOOT OF SNOW, AND THE 00Z UKMET HAS
FLURRIES. MAINTAINED A WATCH FOR ST. MARY'S AND ADDED ALBEMARLE
AND NELSON FOR THIS CYCLE.
A STRONG NORTHERN STREAM UPPER LOW WILL PASS OVERHEAD THURSDAY,
AND MAY VERY WELL RESULT IN SCATTERED TO PERHAPS WIDESPREAD SNOW
SHOWER ACTIVITY DEPENDING ON AVAILABLE MOISTURE AND ANY
INTERACTION WITH THE INCREASINGLY DISTANT OFFSHORE LOW.
OTHERWISE, IT WILL BE COLDER THAN NORMAL WITH INCREASING NORTH
TO NORTHWEST WINDS MID TO LATE WEEK.
LONG TERM /FRIDAY THROUGH MONDAY/
A FEW UPSLOPE SNOW SHOWERS IN THE APPALACHIANS WILL FADE EARLY
FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY THROUGH
SATURDAY. DRY AND CHILLY CONDITIONS EXPECTED THROUGH THIS PERIOD.
HIGHS FRIDAY AND SATURDAY WILL BE ABOUT 5 TO 10 DEGREES BELOW
AVERAGE WITH HIGHS IN THE MIDDLE 30S TO THE LOWER 40S. LOWS WILL
ALSO BE ABOUT 10 DEGREES BELOW AVERAGE REACHING INTO THE LOWER 20S.
COLD TEMPERATURES AND GUSTY WINDS APPROACHING 50 MPH COULD
RESULT IN DANGEROUSLY COLD WIND CHILLS FOR THE APPALACHIANS
THURSDAY INTO FRIDAY.
THE HIGH PRESSURE CENTER WILL MOVE TO THE EAST COAST TO ALLOW FOR A
MODIFYING SOUTHERLY WIND TO DEVELOP LATE SATURDAY THROUGH SUNDAY.
TEMPERATURES WILL STILL BE ON THE CHILLY SIDE WITH HIGHS REACHING
NEAR 40 TO LOWER 40S.
A TROUGH OF LOW PRESSURE TO THE WEST OF THE REGION SUNDAY WILL
MOVE OVER THE REGION SUNDAY NIGHT AND PERSIST ON MONDAY. INCREASING
CLOUDS SUNDAY NIGHT COULD LEAD TO A CHANCE FOR A RAIN OR SNOW SHOWER
SUNDAY NIGHT AND MONDAY. AN AREA OF HIGH PRESSURE WILL BUILD INTO
THE REGION LATE MONDAY INTO MIDDLE OF NEXT WEEK. TEMPERATURES ON
MONDAY WILL REACH NEAR AVERAGE LEVELS.
AVIATION /15Z TUESDAY THROUGH SATURDAY/
WINDS WILL BE SOMEWHAT STEADY STATE, IN THE 20 TO 25 KNOT RANGE,
UNTIL DIMINISHING THIS EVENING. MID OR HIGH LEVEL WAVE CLOUDS
ARE POSSIBLE TODAY, OTHERWISE VFR CONDITIONS PREVAIL.
LOW PRESSURE WILL TRACK SOUTH OF THE AREA WEDNESDAY INTO
WEDNESDAY NIGHT. THE HIGHEST CHANCE FOR SNOW AND SUB-VFR
CONDITIONS IS AT CHO, ALTHOUGH THE METRO TERMINALS COULD SEE A
PERIOD OF LIGHT SNOW AS WELL.
VFR CONDITIONS FRIDAY THROUGH SATURDAY NIGHT. WINDS NORTHWEST 10 TO
20 KNOTS GUSTS 25 TO 30 KNOTS FRIDAY, DIMINISHING NORTHWEST 10 TO 15
KNOTS GUSTS UP TO 25 KNOTS FRIDAY NIGHT. WINDS BECOMING SOUTH 10
KNOTS SATURDAY AND SATURDAY NIGHT.
MARINE
A LARGE AREA OF HIGH PRESSURE WILL DESCEND INTO THE NORTH-
CENTRAL U.S. SINCE THE HIGH WON'T BE DIRECTLY OVERHEAD, WEST-
NORTHWEST WINDS WILL ONLY GRADUALLY DIMINISH TODAY, WITH
NORTHERLY CHANNELING EXPECTED TONIGHT.
LIGHTER WINDS ARE EXPECTED WEDNESDAY. LOCATIONS ALONG THE BAY
COULD APPROACH ADVISORY CRITERIA WEDNESDAY NIGHT DEPENDING ON
THE STRENGTH OF LOW PRESSURE TO THE SOUTH. SOLID SCA TO POSSIBLE
GALES ARE ANTICIPATED THURSDAY INTO FRIDAY.
SMALL CRAFT ADVISORIES LIKELY FRIDAY AND FRIDAY NIGHT. WINDS
NORTHWEST 15 TO 20 KNOTS GUSTS UP TO 30 KNOTS FRIDAY, DIMINISHING
NORTHWEST 15 KNOTS GUSTS 20 TO 25 KNOTS FRIDAY NIGHT. WINDS
BECOMING SOUTH 10 KNOTS GUSTS 15 KNOTS SATURDAY AND SATURDAY
NIGHT.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...SMALL CRAFT ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MDZ008.
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR MDZ017.
VA...WINTER WEATHER ADVISORY FROM 7 AM WEDNESDAY TO 7 AM EST
THURSDAY FOR VAZ025-503-504-508.
WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
MORNING FOR VAZ036-037.
WV...WINTER WEATHER ADVISORY FROM 7 AM WEDNESDAY TO 7 AM EST
THURSDAY FOR WVZ505.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST WEDNESDAY FOR ANZ530>543.
SYNOPSIS...ADS/DHOF
NEAR TERM...DHOF/CJL
SHORT TERM...DHOF
LONG TERM...KLW
AVIATION...ADS/KLW/DHOF/CJL
MARINE...ADS/KLW/DHOF
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