878
FXUS61 KAKQ 210636
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
136 AM EST SAT DEC 21 2024
SYNOPSIS
LOW PRESSURE WILL TRACK FARTHER AWAY TOWARD THE CANADIAN
MARITIMES DURING TODAY, AS HIGH PRESSURE STARTS TO BUILD TOWARD
THE AREA FROM THE NORTHWEST. DRY WEATHER AND MUCH COOLER
TEMPERATURES ARE EXPECTED TODAY THROUGH MONDAY, AS THE HIGH
BUILDS INTO AND OVER THE REGION. A SLOW MODERATING TREND IN
TEMPERATURES WILL START TUESDAY.
NEAR TERM /THROUGH TODAY/
AS OF 725 PM EST FRIDAY...
KEY MESSAGE:
- LIGHT RAIN SHOWERS MIXED WITH SNOW SHOWERS AT TIMES THIS
EVENING ACROSS THE MD EASTERN SHORE, NO SNOW ACCUMULATION.
- CLEARING OVERNIGHT WITH LOWS IN THE UPPER 20S TO LOW-MID 30S.
EVENING AFTERNOON WX ANALYSIS INDICATES DEEPENING ~1000MB LOW
PRESSURE WELL OFF THE DELMARVA COAST, WITH THE ASSOCIATED UPPER
SHORTWAVE MOVING E-SE TO THE CAROLINA COASTAL PLAIN. GENERALLY
TOO DRY FOR MOST OF THE CWA WITH JUST A FEW SPRINKLES ACROSS
SOUTH CENTRAL VA. HOWEVER, JUST ENOUGH MOISTURE LINGERS ACROSS
THE EASTERN SHORE, AND WITH COLD AIR NOT TOO FAR OFF THE SFC
(NOTE THAT MODEL 1000-850 THICKNESSES ARE QUITE COLD AT ~1290
M WHICH DOES SUPPORT AT LEAST SOME SNOW MIXING IN). LATEST OBS
AT EASTON AND NOW AS FAR SE AS SBY HAVE SHOWN EITHER RA/SN OR SN
DESPITE SFC TEMPERATURES 35-37F WITH DEW PTS ALSO ABOVE
FREEZING. THE WARM SFC TEMPERATURES WILL LIMIT ANY ACCUMULATION
AND ROADS WILL JUST BE WET, BUT HAVE INDICATED CHC FOR MIXED
RAIN/SNOW SHOWERS IN THE GRIDS THIS EVENING. TOTAL QPF ARE ONLY
~0.05-0.10" AT MOST. MOSTLY CLOUDY THIS EVENING, THEN BECOMING
PARTLY CLOUDY TO MOSTLY CLEAR OVERNIGHT W OF THE BAY. ON THE
EASTERN SHORE IT WILL BE MAINLY CLOUDY WITH PARTIAL CLEARING
WELL AFTER MIDNIGHT. TURNING COLDER WITH LOWS IN THE UPPER 20S
TO LOW-MID 30S.
SHORT TERM /TONIGHT THROUGH MONDAY/
AS OF 240 PM EST FRIDAY...
KEY MESSAGE:
- COLD AND DRY WEATHER IS EXPECTED THIS WEEKEND, WITH WIND
CHILLS IN THE SINGLE DIGITS AND TEENS SUNDAY/MONDAY MORNING.
COOLER/DRY WX IS EXPECTED ON SAT, AS STRONG HIGH PRESSURE BUILDS
INTO THE GREAT LAKES AND THE OFFSHORE LOW TRACKS ACROSS ATLANTIC
CANADA. IN ADDITION, BREEZY CONDITIONS (GUSTS TO 25-30 MPH) ARE
EXPECTED DURING THE DAY. FORECAST HIGHS ON SAT ARE ONLY IN THE UPPER
30S TO MID 40S. ANOTHER PUSH OF CAA IS EXPECTED SAT NIGHT THROUGH
SUN NIGHT, AS THE SFC HIGH BUILDS TOWARD THE AREA (AND BECOMES
CENTERED OVER THE MID-ATLANTIC/NORTHEAST BY SUN NIGHT). COLD SAT
NIGHT WITH LOWS MAINLY IN THE UPPER TEENS TO MID 20S. IT MAY STILL
SOMEWHAT BREEZY NEAR THE COAST WITH BAY EFFECT CLOUDS, BUT WINDS
SHOULD BECOME FAIRLY LIGHT INLAND. WIND CHILLS SUNDAY MORNING WILL
BE IN THE TEENS, WITH SINGLE DIGITS POSSIBLE ON THE MD EASTERN
SHORE. COLD BUT SUNNY OR MOSTLY SUNNY ON SUN, WITH HIGHS ONLY
RANGING THROUGH THE 30S. WITH THE HIGH OVERHEAD, WINDS BECOME LIGHT
OR CALM SUNDAY NIGHT. LOWS WILL BE IN THE MID TO UPPER TEENS INLAND,
WITH UPPER TEENS TO MID 20S NEAR THE COAST. WITH THE VERY LIGHT
WINDS, WIND CHILLS WILL NOT BE MUCH LOWER THAN THE ACTUAL AIR
TEMPERATURES. THE STRONG HIGH BECOMES CENTERED JUST OFFSHORE OF THE
NEW ENGLAND COAST ON MONDAY...BUT SFC RIDGING WILL STILL BE OVER THE
LOCAL AREA WITH VERY LIGHT WINDS EXPECTED DURING THE DAY. MAINLY
SUNNY AND COLD ON MON WITH HIGHS IN THE MID 30S-MID 40S.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
AS OF 240 PM EST FRIDAY...
KEY MESSAGE:
- A SLOW MODERATING TREND IN EXPECTED TUESDAY THROUGH FRIDAY
WITH INCREASING CLOUDS.
TEMPERATURES WILL MODERATE SOME DURING THE EXTENDED PERIOD.
THE 1036-1038MB HIGH IS PROGGED TO BE WELL OFFSHORE OF THE NEW
ENGLAND COAST ON TUESDAY. THE MID/UPPER LEVEL FLOW FLATTENS OUT, BUT
A WEAK SHORTWAVE WILL PASS BY TO OUR NORTH TUESDAY INTO TUESDAY
NIGHT. NO PRECIPITATION IS EXPECTED WITH THIS SHORTWAVE (ASIDE FROM
PERHAPS AN ISOLATED SHOWER UP NORTH)...BUT IT WILL DRAG A BACKDOOR
COLD FRONT THROUGH THE AREA BY CHRISTMAS (WEDNESDAY) MORNING. A
PROLONGED PERIOD OF LIGHT ONSHORE FLOW IS POSSIBLE FROM WED-FRI AS
HIGH PRESSURE TRIES TO BUILD TOWARD THE AREA. AT THE SAME TIME, A
COUPLE OF SOUTHERN STREAM DISTURBANCES WEAKEN AS THEY APPROACH THE
LOCAL AREA. FOR NOW, WILL KEEP DRY WEATHER FOR TUE, WITH JUST 15-30%
POPS FOR RAIN WED THROUGH FRI, WITH A PARTLY TO MOSTLY CLOUDY SKY.
STILL COLD TUESDAY AM WITH LOWS IN THE 20S. HIGHS WILL RANGE FROM
THE MID 40S TO MID 50S THROUGH THE PERIOD (WHICH IS CLOSE TO
AVERAGE). LOWS MODERATE INTO THE 30S-LOWER 40S BY LATE NEXT WEEK.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
AS OF 135 AM EST SATURDAY...
EXCEPT FOR SBY WHERE AN IFR CIG STILL LINGERED, VFR CONDITIONS
WERE PREVAILING AT THE OTHER TAF SITES AS OF 130 AM. IFR CIG AT
SBY WILL GRADUALLY IMPROVE TO MVFR THEN VFR CONDITIONS THROUGH
12Z THIS MORNING. NW OR N WINDS AROUND 10 KT OR LESS ARE LIKELY
THROUGH EARLY THIS MORNING, BEFORE INCREASING BY LATER THIS
MORNING INTO EARLY THIS EVENING. GUSTS TO 25 KT ARE LIKELY MOST
AREAS FROM ~14Z THROUGH ~21Z TODAY. DIMINISHING WINDS THIS
EVENING (THOUGH REMAINING A BIT BREEZY AT THE COAST INITIALLY).
OTHERWISE, VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES FROM
LATER THIS MORNING INTO SUN MORNING.
OUTLOOK: LESS WIND WITH DRY WX/VFR CIGS ARE EXPECTED SUN AND
MON.
MARINE
AS OF 240 PM EST FRIDAY...
KEY MESSAGES:
- OFFSHORE LOW PRESSURE LEADS TO MARGINAL SMALL CRAFT ADVISORY
CONDITIONS THROUGH THIS AFTERNOON AND EVENING.
- STRONGER WINDS ARE EXPECTED TONIGHT, ESPECIALLY AFTER
MIDNIGHT, AND THROUGH SATURDAY BEHIND A COLD FRONT. WINDS OF
15-25 KT WITH GUSTS TO 30-35 KT ARE CURRENTLY FORECAST.
- SEAS STAY ELEVATED THROUGH SUNDAY. CALMER MARINE CONDITIONS
ARE EXPECTED MONDAY THROUGH MIDWEEK.
A DIGGING UPPER-LEVEL TROUGH W OF THE AREA IS LEADING TO DEEPENING
SFC LOW PRESSURE ABOUT 250 MILES OFFSHORE OF OCEAN CITY. A
TIGHTENING PRESSURE GRADIENT ON THE BACKSIDE OF THE LOW HAS LED TO
OCCASIONALLY ELEVATED NNW WINDS, AND CURRENT OBS ARE AVERAGING
AROUND 15 KT WITH GUSTS TO 20 KT. SEAS OFFSHORE ARE GENERALLY 3-5
FT. SIMILAR CONDITIONS ARE EXPECTED OVER THE NEXT FEW HOURS AS THE
LOW DEEPENS FURTHER, BUT ALSO DEPARTS FURTHER OFFSHORE TO OUR NE. IN
FACT, WINDS MAY ACTUALLY INCREASE TO 15-20 KT WITH GUSTS TO 25 KT BY
THIS EVENING. BASED ON ALL OF THESE FACTORS, HAVE STARTED THE SMALL
CRAFT ADVISORY FOR ALL WATERS EXCEPT THE RIVERS AND CURRITUCK SOUND
AS OF THIS UPDATE. A STRONGER SURGE OF WINDS IS EXPECTED TONIGHT
INTO SATURDAY AS COLD ADVECTION INTENSIFIES BEHIND A REINFORCING
COLD FRONT AND SCAS ARE IN EFFECT EVERYWHERE DURING THIS TIME. NW
WINDS INCREASE TO 20-25 KT WITH GUSTS TO 30-35 KT ON THE CHESAPEAKE
BAY AND COASTAL WATERS. ANY OCCURRENCES OF GUSTS >34 KT CAN BE
HANDLED WITH SPECIAL MARINE WARNINGS, AS NECESSARY. SLIGHTLY WEAKER
WINDS ARE EXPECTED IN THE UPPER RIVERS AND CURRITUCK SOUND, BUT
STILL SOLIDLY TO SCA CRITERIA. SEAS DURING THIS TIME ARE FORECAST TO
BUILD TO 4-6 FT, WITH THE POTENTIAL FOR 7+ SEAS OFFSHORE OF THE SRN
VA AND NC COASTAL WATERS. WAVES IN THE CHESAPEAKE BAY ALSO BUILD TO
3-5 FT. WINDS GRADUALLY DIMINISH HEADING INTO SUNDAY AS THE GRADIENT
SLACKENS AND HIGH PRESSURE BUILDS IN FROM THE N. SEAS WILL ALSO
SLOWLY FALL, THOUGH 5 FT SEAS LINGER THROUGH MOST OF SUNDAY. BASED
ON THIS, HAVE EXTENDED THE SCA FOR THE COASTAL WATERS S OF THE
PARRAMORE ISLAND THROUGH 18Z/1 PM SUNDAY. FUTURE SHIFTS MAY ALSO
NEED TO EXTEND THE NORTHERN WATERS.
MUCH WEAKER WINDS ARE EXPECTED SUNDAY NIGHT AND ESPECIALLY MONDAY AS
THE CENTER OF THE HIGH MOVES VERY NEAR THE AREA. WINDS BRIEFLY TURN
SOUTHERLY TUESDAY AND THEN NORTHERLY WEDNESDAY BEHIND ANOTHER COLD
FRONT. ADDITIONAL SCAS COULD BE REQUIRED AT SOME POINT, THOUGH
OVERALL CONFIDENCE IS QUITE LOW FOR NEXT WEEK.
AKQ WATCHES/WARNINGS/ADVISORIES
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR ANZ630>632-650-
652.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ635>637.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR ANZ638.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR ANZ654-656-658.
SYNOPSIS...TMG
NEAR TERM...ERI/LKB
SHORT TERM...ERI/TMG
LONG TERM...ERI/TMG
AVIATION...TMG
MARINE...MAM/SW
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