104
FXUS61 KLWX 201921
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
221 PM EST MON JAN 20 2025
SYNOPSIS
ARCTIC HIGH PRESSURE WILL MAINTAIN CONTROL LEADING TO WELL BELOW
NORMAL TEMPERATURES AND DANGEROUSLY COLD WIND CHILLS THE FIRST
HALF OF THIS WEEK. A DISTURBANCE MAY BRING FLURRIES OR A FEW SNOW
SHOWERS TUESDAY AFTERNOON INTO TUESDAY NIGHT. TEMPERATURES WILL
BEGIN TO MODERATE LATE THIS WEEK AS HIGH PRESSURE BEGINS TO LIFT
AWAY. LOW PRESSURE DEVELOPING OFFSHORE COULD APPROACH THE REGION
LATE IN THE WEEK, WITH ANOTHER SYSTEM POSSIBLY APPROACHING THE
REGION LATE IN THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
ASIDE FROM A FEW FLURRIES ACROSS NORTHERN MD AND OVER THE
APPALACHIANS, MAINLY DRY CONDITIONS ARE EXPECTED THROUGH THIS
EVENING. FLURRIES OVER THE MOUNTAINS SHOULD BECOME MORE SPARSE
OVERNIGHT AS WINDS BECOME LIGHTER AND DRY AIR MOVES IN.
DANGEROUS WIND CHILLS ARE ANTICIPATED THROUGH TONIGHT,
ESPECIALLY FOR THE HIGHER ELEVATIONS. COLD WEATHER HEADLINES
REMAIN IN EFFECT FOR WIND CHILLS AROUND 0 TO THE SINGLE DIGITS
BELOW ZERO FOR MUCH OF THE AREA TONIGHT, WITH -15 TO -30 AT
HIGHER ELEVATIONS (COLDEST ON THE PEAKS OF THE ALLEGHENIES).
SHORT TERM /TUESDAY THROUGH THURSDAY/
A PRONOUNCED WAVE ALOFT WILL PIVOT ACROSS THE AREA TUESDAY
AFTERNOON AND EVENING. THE WAVE, COUPLED WITH BRIEF UPSLOPE FLOW
AND MODEST MOISTURE, MAY RESULT IN MOUNTAIN SNOW SHOWERS DURING
THE DAY INTO THE EVENING. A COATING TO A COUPLE INCHES IS
POSSIBLE ALONG AND WEST OF THE ALLEGHENY FRONT. FURTHER EAST,
MID-LEVEL MOISTURE AND LIFT WILL BE PRESENT MUCH OF THE DAY, BUT
THE LOW LEVELS LOOK QUITE DRY. THIS SHOULD LIMIT ANY PRECIP TO
JUST A FEW FLURRIES, ESPECIALLY EAST OF I-81. TOWARDS EVENING,
LOW-LEVEL MOISTURE AND LOW/MID-LEVEL FGEN SUBTLY INCREASES A
BIT, AND A FEW SNOW SHOWERS ARE POSSIBLE DURING THIS TIME.
ALTHOUGH AMOUNTS SHOULD BE JUST A LIGHT COATING AND RELATIVELY
SPOTTY, A FEW PIECES OF GUIDANCE HAVE CLOSE TO AN INCH IN
ISOLATED SPOTS. REGARDLESS, ANY ACCUMULATION WILL RESULT IN
SLICK TRAVEL GIVEN THE VERY COLD TEMPERATURES.
SPEAKING OF THE COLD TEMPERATURES, BITTER COLD WILL CONTINUE
THROUGH THE MIDDLE OF THE WEEK. TEMPERATURES WILL BE 20 TO 30
DEGREES BELOW NORMAL. WHEN COMBINED WITH THE WIND (ESPECIALLY AT
HIGHER ELEVATIONS), THIS WILL RESULT IN DANGEROUS WIND CHILLS.
COLD WEATHER HEADLINES HAVE BEEN EXTENDED THROUGH THURSDAY
MORNING TO ACCOUNT FOR THE DANGEROUS COLD. BELOW IS A LIST OF
ACTIONS WE CAN TAKE TO ENSURE SAFETY DURING THIS COLD SNAP:
-DRESS IN LAYERS INCLUDING A HAT, FACE MASK, AND GLOVES IF YOU
MUST GO OUTSIDE.
-TO PREVENT WATER PIPES FROM FREEZING; WRAP OR DRAIN OR ALLOW
THEM TO DRIP SLOWLY.
-DRAIN IN-GROUND SPRINKLER SYSTEMS AND COVER ABOVE GROUND
PIPES.
-KEEP PETS INDOORS AS MUCH AS POSSIBLE.
-MAKE SURE OUTDOOR ANIMALS HAVE A WARM, DRY SHELTER, FOOD, AND
UNFROZEN WATER.
-MAKE FREQUENT CHECKS ON OLDER FAMILY, FRIENDS, AND NEIGHBORS.
ENSURE PORTABLE HEATERS ARE USED CORRECTLY. DO NOT USE
GENERATORS OR GRILLS INSIDE.
TEMPERATURES WILL MODERATE SOME ON THURSDAY, BUT WILL REMAIN
BELOW NORMAL WITH HIGHS IN THE 20S AND 30S. ANY LINGERING
MOISTURE WILL EITHER REMAIN FROZEN OR RE-FREEZE THROUGH THE
MIDDLE OF THE WEEK GIVEN THE PERSISTENT VERY COLD TEMPS, SO
REMAIN ALERT FOR ICY PATCHES WHEN TRAVELING.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
THE PERIOD CLOSING OUT THE WORK WEEK AND HEADING INTO THE WEEKEND
WILL PROVIDE A SLOW BUT STEADY RETURN TO NEAR AVERAGE TEMPERATURES.
CLOSING OUT THURSDAY NIGHT, A WAVE OF LOW PRESSURE CONTINUES TO
TREND FURTHER SOUTH AND EAST OF THE MID-ATLANTIC REGION. THIS
APPEARS TO BE A THEME OF ALL GLOBAL ENSEMBLE SUITES. AS SUCH, THE
THREAT FOR ANY PRECIPITATION THREATS WOULD BE CONFINED TO THE
CAROLINAS AND POINTS SOUTHWARD. WHILE THE NORTHERN BRANCH OF THE JET
STREAM REMAINS ACTIVE, ADDITIONAL DISTURBANCES ALOFT ARE SLATED TO
PASS THROUGH THE SOUTHEASTERN U.S. LATE IN THE WORK WEEK. SHIFTING
FOCUS TO THE WEEKEND, EXPECT MID/UPPER HEIGHTS TO FLATTEN OUT AND
EVEN BUILD SOME. ULTIMATELY THIS CARRIES TEMPERATURES TO NEAR
AVERAGE FOR LATE JANUARY BY THE WEEKEND. THIS PERIOD IS LARGELY DRY
ASIDE FROM SOME UPSLOPE SNOW SHOWERS ALONG THE ALLEGHENIES ON FRIDAY
MORNING.
AFTER SURFACE HIGH PRESSURE TAKES CHARGE OVER THE WEEKEND, THE
GUIDANCE CONTINUES TO SHOW UPSTREAM HEIGHT FALLS BRINGING A SHIFT TO
THE PATTERN BY LATE SUNDAY INTO MONDAY. DETERMINISTIC MODELS
CONTINUE TO EXHIBIT QUITE A BIT OF VARIABILITY INTO THIS PERIOD.
HOWEVER, EVEN TOWARD THE COLDER SIDE OF THE SPREAD, TEMPERATURES AT
WORST STAY NEAR AVERAGE. THERE IS SOME HINT AT WINTRY PRECIPITATION
AT THE ONSET AS HIGH PRESSURE IS SLOW TO EXIT THE NEW ENGLAND COAST.
IF THIS WERE TO OCCUR, IT WOULD LIKELY BE FREEZING RAIN OR SLEET AS
LOW-LEVEL COLD AIR IS OFTEN SLOW TO ERODE IN THE MIDDLE OF WINTER.
GIVEN THIS IS AROUND A WEEK OUT, DETAILS WILL LIKELY REMAIN FUZZY
THE NEXT FEW DAYS.
AVIATION /19Z MONDAY THROUGH SATURDAY/
AN ARCTIC AIRMASS CONTINUES TO SPILL INTO THE AREA ON GUSTY
NORTHWEST WINDS. WIND GUSTS WILL START TO SUBSIDE WITH SUNSET,
ALONG WITH DISSIPATION OF ANY REMAINING STRATOCUMULUS CLOUDS.
A DISTURBANCE WILL CROSS THE AREA TUESDAY, RESULTING IN MID-LEVEL
CEILINGS. THERE IS A LOW CHANCE FOR MVFR CONDITIONS AND A FEW
SNOW SHOWERS OR FLURRIES DURING THE AFTERNOON AND EVENING. WINDS
WILL BE LIGHT FROM THE WEST TO SOUTHWEST.
VFR CONDITIONS ARE EXPECTED WEDNESDAY. A FEW NORTHWESTERLY WIND
GUSTS TO 20 KT ARE POSSIBLE, ESPECIALLY IN THE MORNING.
ANTICIPATING VFR CONDITIONS FOR THURSDAY INTO THE WEEKEND WITH
DRY WEATHER EXPECTED. INITIAL SOUTHERLY WINDS GIVE WAY TO
NORTHWESTERLIES BY FRIDAY AS A COLD FRONT EXITS OFFSHORE. HIGH
PRESSURE SETTLES NEAR THE AREA WITH WINDS TURNING SOUTHWESTERLY
ON SATURDAY.
MARINE
GUSTY NW WINDS AND VERY COLD WEATHER ARE EXPECTED THROUGH
TONIGHT. WINDS WILL GRADUALLY DIMINISH LATER TONIGHT INTO
TUESDAY ENDING THE FREEZING SPRAY THREAT FOR A TIME, BUT WINDS
LIKELY INCREASE AGAIN TUESDAY NIGHT INTO WEDNESDAY WITH RENEWED
SCAS/FREEZING SPRAY POSSIBLE.
WINDS DURING THE LATTER PORTIONS OF THE WORK WEEK SHOULD STAY BELOW
SMALL CRAFT ADVISORY LEVELS. WITH A COLD FRONT EXITING OFFSHORE,
FORECAST WINDS SHIFT FROM SOUTHWESTERLY TO NORTH-NORTHWESTERLY ON
FRIDAY.
LWX WATCHES/WARNINGS/ADVISORIES
DC...COLD WEATHER ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
TUESDAY FOR DCZ001.
COLD WEATHER ADVISORY FROM 10 PM TUESDAY TO 10 AM EST THURSDAY
FOR DCZ001.
MD...COLD WEATHER ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
TUESDAY FOR MDZ006-008-011-013-014-503>508.
COLD WEATHER ADVISORY FROM 10 PM TUESDAY TO 10 AM EST THURSDAY
FOR MDZ003>006-008-011-013-014-016>018-502>508.
EXTREME COLD WARNING UNTIL 7 AM EST THURSDAY FOR MDZ001-501.
COLD WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR MDZ003>005-
502.
VA...COLD WEATHER ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
TUESDAY FOR VAZ038>040-051-053-054-501-502-505-506-526-
527.
COLD WEATHER ADVISORY FROM 10 PM TUESDAY TO 10 AM EST THURSDAY
FOR VAZ025>031-036>040-050-051-053>057-501-502-505-506-
526-527.
EXTREME COLD WARNING UNTIL 7 AM EST THURSDAY FOR VAZ503-504-
507-508.
COLD WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR VAZ025>031.
WV...COLD WEATHER ADVISORY FROM 10 PM TUESDAY TO 10 AM EST THURSDAY
FOR WVZ050>053-055-502-504.
EXTREME COLD WARNING UNTIL 7 AM EST THURSDAY FOR WVZ501-503-
505-506.
COLD WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR WVZ050>053-
055-502-504.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ530>534-
537>543.
COLD WEATHER ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
TUESDAY FOR ANZ530.
COLD WEATHER ADVISORY FROM 10 PM TUESDAY TO 10 AM EST THURSDAY
FOR ANZ530.
FREEZING SPRAY ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ531-
532-537-539-540.
FREEZING SPRAY ADVISORY UNTIL 10 AM EST TUESDAY FOR ANZ533-534-
541-543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
536.
SYNOPSIS...DHOF
NEAR TERM...DHOF
SHORT TERM...DHOF
LONG TERM...BRO
AVIATION...ADS/BRO/DHOF
MARINE...BRO/DHOF
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