694
FXUS61 KLWX 171936
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
236 PM EST TUE DEC 17 2024
SYNOPSIS
HIGH PRESSURE WILL BUILD INTO THE REGION LATE THIS AFTERNOON
INTO TONIGHT. THE HIGH WILL MOVE TO THE WESTERN ATLANTIC
WEDNESDAY TO ALLOW ANOTHER LOW PRESSURE SYSTEM TO IMPACT THE
AREA WEDNESDAY INTO WEDNESDAY EVENING. HIGH PRESSURE WILL CROSS
THE AREA THURSDAY WITH ANOTHER LOW APPROACHING THE GREAT LAKES
BY FRIDAY.
NEAR TERM /THROUGH TONIGHT/
AN AREA OF HIGH PRESSURE OVER THE MIDDLE OHIO VALLEY WILL MOVE
IN OVER THE CWA LATER THIS AFTERNOON THROUGH TONIGHT. ASIDE FROM
HIGH CLOUDS STREAKING ACROSS THE CWA FROM SOUTHWEST TO NORTHEAST
THIS AFTERNOON, THE REGION WILL STAY DRY WITH TEMPERATURES
RISING NEARLY 15 DEGREES ABOVE AVERAGE FOR MID-DECEMBER.
TEMPERATURES HAVE ALREADY REACHED 60 DEGREES IN A LARGE PART OF
THE PIEDMONT.
DRY CONDITIONS CONTINUE THIS EVENING INTO MUCH OF THE OVERNIGHT
WITH HIGH PRESSURE STILL IN CONTROL OVERHEAD. TEMPERATURES
OVERNIGHT WILL BE NEARLY 10 DEGREES COLDER THAN THEY WERE THIS
MORNING WITH LOWS DROPPING INTO THE UPPER 20S TO LOWER 30S IN
PARTS OF WESTERN AND CENTRAL MARYLAND, EASTERN WEST VIRGINIA AND
THE APPALACHIANS. ELSEWHERE AND FURTHER EAST, LOWS WILL DROP
INTO THE MIDDLE TO UPPER 30S. IT IS THE AREAS THAT ARE NEAR
FREEZING OR BELOW FREEZING THAT WE NEED TO MONITOR FOR ANY LIGHT
ISOLATED MIXED PRECIPITATION LATE TONIGHT INTO EARLY WEDNESDAY.
THE NEXT LOW PRESSURE SYSTEM IS APPROACHING QUICKLY LATE
TONIGHT. IT COULD SPREAD SOME LIGHT RAIN INTO THE NORTHWEST
ZONES WHERE TEMPERATURES ARE MARGINAL FOR FROZEN PRECIPITATION.
THE MIX COULD BE MOSTLY FREEZING RAIN IN WESTERN MD AND
NORTHEASTERN WV AND MAY ONLY LAST FOR A FEW HOURS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
TEMPERATURES WILL MODIFY THROUGH THE DAY WEDNESDAY, WHERE ANY
FROZEN PRECIPITATION SHOULD TRANSITION TO PLAIN RAIN. THE LOW
PRESSURE SYSTEM WILL IMPACT THE AREA WEDNESDAY INTO WEDNESDAY
NIGHT. RAINFALL AMOUNTS WITH THIS SYSTEM WILL AVERAGE AROUND A
QUARTER OF AN INCH NEAR THE METROS TO UPWARDS OF THREE QUARTERS
OF AN INCH NEAR WESTERN MARYLAND.
HIGHS WEDNESDAY WILL BE COOLER, BUT STILL SLIGHTLY ABOVE
AVERAGE FOR MID-DECEMBER. GUSTY WINDS, ESPECIALLY IN THE
MOUNTAINS, WILL OCCUR AS THE COLD FRONT CROSSES WEDNESDAY NIGHT.
FOR THE TYPICAL UPSLOPE AREAS OF THE ALLEGHENIES, PRECIPITATION
WILL CHANGE OVER TO SNOW, BUT AMOUNTS APPEAR TO BE AN INCH OR
LESS.
COOLER THURSDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE
DEPARTING STORM SYSTEM. HIGHS WILL BE CLOSE TO AVERAGE. A FEW
SNOW SHOWERS MAY LINGER INTO MID- MORNING ACROSS THE
ALLEGHENIES, BUT OTHERWISE DRY CONDITIONS ARE EXPECTED.
LONG TERM /FRIDAY THROUGH TUESDAY/
AN UPPER LEVEL TROUGH AND ASSOCIATED CLIPPER LOW WILL MOVE THROUGH
THE AREA ON FRIDAY. THIS SYSTEM WILL BE RATHER MOISTURE STARVED IN
NATURE, BUT MAY PRODUCE A FEW MIXED RAIN AND SNOW SHOWERS TO THE
EAST OF THE MOUNTAINS. FURTHER WEST, UPSLOPE SNOW SHOWERS APPEAR
LIKELY IN THE ALLEGHENIES. THESE UPSLOPE SNOW SHOWERS WILL CONTINUE
ON AND OFF BEHIND THE SYSTEM FRIDAY NIGHT INTO SATURDAY, WITH A FEW
INCHES OF ACCUMULATION POSSIBLE IN THE MOUNTAINS.
NORTHWESTERLY FLOW BEHIND THIS SYSTEM WILL TRANSPORT A COLD AIRMASS
INTO THE REGION FOR THE WEEKEND. CONDITIONS WILL STAY DRY (WITH THE
EXCEPTION OF A FEW SNOW SHOWERS IN THE ALLEGHENIES ON SATURDAY), BUT
TEMPERATURES WILL BE WELL BELOW NORMAL. HIGHS WILL ONLY BE IN THE
20S AND 30S ON SATURDAY, AND MAY STRUGGLE TO REACH FREEZING AREAWIDE
BY SUNDAY. OVERNIGHT LOWS WILL GENERALLY BE IN THE TEENS.
HIGH PRESSURE WILL BUILD TO OUR NORTH ON MONDAY, LEADING TO SUNNY
SKIES. TEMPERATURES WILL REMAIN BELOW NORMAL, WITH DAYTIME HIGHS IN
THE UPPER 20S AND 30S.
AVIATION /17Z TUESDAY THROUGH SATURDAY/
VFR CONDITIONS THROUGH TONIGHT WITH HIGH PRESSURE MOVING
OVERHEAD. MVFR OR IFR CONDITIONS POSSIBLE WEDNESDAY INTO
WEDNESDAY NIGHT AS ANOTHER LOW PRESSURE SYSTEM BRINGS RAIN TO
THE REGION. VFR CONDITIONS RETURN THURSDAY AND THURSDAY NIGHT
WITH THE NEXT HIGH PRESSURE CENTER BUILDING INTO THE REGION.
PREVAILING VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED ON FRIDAY. A
FEW RAIN OR SNOW SHOWERS MAY BE POSSIBLE, WHICH COULD BRIEFLY DROP
CONDITIONS TO SUB-VFR. VFR CONDITIONS AND NORTHWESTERLY WINDS ARE
EXPECTED FRIDAY NIGHT THROUGH SATURDAY.
MARINE
HIGH PRESSURE WILL BUILD OVERHEAD THIS AFTERNOON THROUGH
TONIGHT. LOW PRESSURE WILL SPREAD SOME RAIN ACROSS THE CWA
WEDNESDAY INTO WEDNESDAY EVENING. BEHIND THE DEPARTING LOW LATER
WEDNESDAY NIGHT INTO THURSDAY, HIGH PRESSURE WILL BUILD IN AND
CAUSE NORTHWESTERLY WINDS TO INCREASE. SCA CONDITIONS COULD
START OVER ALL WATERS WEDNESDAY NIGHT AND INTO THURSDAY.
SUB-SCA WINDS ARE EXPECTED ON FRIDAY. WINDS TURN NORTHWESTERLY
FRIDAY NIGHT INTO SATURDAY. SCA CONDITIONS APPEAR LIKELY IN
NORTHWESTERLY FLOW FRIDAY NIGHT INTO SATURDAY.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
SYNOPSIS...CPB
NEAR TERM...KLW/CPB
SHORT TERM...CPB
LONG TERM...KJP
AVIATION...KLW/KJP
MARINE...KLW/KJP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page