451
FXUS61 KPHI 190649
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
149 AM EST WED FEB 19 2025
SYNOPSIS
A STRONG AREA OF HIGH PRESSURE CENTERED ACROSS THE MIDWEST AND
NORTHERN PLAINS WILL EXTEND MORE INTO OUR AREA INTO TODAY. AN
AREA OF LOW PRESSURE DEVELOPS OFF THE CAROLINA COAST WEDNESDAY
THEN TRACKS NORTHEASTWARD AND OUT TO SEA THROUGH THURSDAY. HIGH
PRESSURE WILL BUILD IN LATER FRIDAY INTO SATURDAY, THEN LOW
PRESSURE TRACKS ACROSS THE GREAT LAKES REGION EARLY NEXT WEEK
WITH A WEAK COLD FRONT APPROACHING OUR AREA.
NEAR TERM /THROUGH THURSDAY/
HIGH PRESSURE BUILDING IN FROM THE WEST SLIDES SOUTH AND OFF
THE MID- ATLANTIC COAST LATE TONIGHT THROUGH WEDNESDAY MORNING.
ANOTHER COLD AND BREEZY NIGHT ON TAP WITH LOWS DROPPING INTO THE
SINGLE DIGITS IN THE SOUTHERN POCONOS, AND IN THE TEENS
ELSEWHERE. MIN WIND CHILL VALUES WILL MOSTLY BE IN THE SINGLE
DIGITS, BUT AS LOW AS -13 IN PORTIONS OF THE SOUTHERN POCONOS.
WILL GO AHEAD AND ISSUE A COLD WEATHER ADVISORY FOR CARBON AND
MONROE COUNTIES LATE TONIGHT THROUGH WEDNESDAY MORNING.
COLD AND DRY FOR MOST OF THE AREA ON WEDNESDAY. TEMPERATURES
WILL STRUGGLE TO REACH THE FREEZING MARK WITH HIGHS GENERALLY IN
THE MID AND UPPER 20S.
A DEEP CLOSED H5 LOW MOVES INTO THE MIDWEST ON WEDNESDAY, AND
SURFACE LOW PRESSURE DEVELOPS OUT AHEAD OF IT OVER THE GULF
COAST STATES. THIS LOW LIFTS TO THE NORTH AND EAST AND TAKES A
RUN AT THE MID-ATLANTIC DURING THE DAY. SNOW WILL MOVE INTO THE
EASTERN SHORES OF MARYLAND AND SOUTHERN DELAWARE LATE IN THE
DAY, AND MINIMAL SNOW ACCUMULATIONS (LESS THAN AN INCH) ARE
POSSIBLE THROUGH DUSK.
REGARDING THIS STORM, MOST OF THE MODELS CONTINUE TO SHOW A
SOUTHERN AND EASTWARD TRACK, KEEPING THE BULK OF THE SNOW SOUTH
AND EAST OF THE LOCAL FORECAST AREA. HOWEVER, THE NAM REMAINS
BULLISH WITH WARNING LEVEL SNOW ACROSS PORTIONS OF DELMARVA AND
SOUTHEAST NEW JERSEY. ONCE AGAIN, THE NAM SEEMS TOO EXPLOSIVE
GIVEN A RELATIVE LACK OF UPPER LEVEL SUPPORT, AND THE QPF FIELD
IS FAR DISPLACED FROM THE CENTER OF THE LOW. WRF-NSSL IS NOW
SHOWING WARNING LEVEL SNOW ACROSS PORTIONS OF SOUTHERN DELAWARE
AND EVEN INTO FAR SOUTHERN NEW JERSEY, BUT THIS IS THE ONLY
MODEL INDICATING ANYTHING CLOSE TO THAT. CONSENSUS GUIDANCE
KEEPS THE LOW TOO FAR SOUTH FOR MUCH.
THE SURFACE LOW WILL PASS OFF THE MID-ATLANTIC COAST LATE
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. ONCE THE SURFACE LOW
MOVES OFFSHORE, THE CLOSED H5 LOW WILL PASS THROUGH THE REGION
THURSDAY AFTERNOON. THIS WILL BRING WIDELY SCATTERED SHOW
SHOWERS TO THE REGION WITH MINIMAL SNOW ACCUMULATION.
OVERALL, THE FOLLOWING SNOWFALL TOTALS CAN BE EXPECTED:
LESS THAN AN INCH OVER THE SOUTHERN POCONOS, NORTHERN NEW
JERSEY, THE LEHIGH VALLEY DOWN TO THE I-95 CORRIDOR, AND THE
DELAWARE VALLEY.
UP TO AN INCH OR SO FOR MOST OF SOUTHERN NEW JERSEY AND MOST OF
COASTAL NEW JERSEY.
1 TO 3 INCHES FOR SOUTHERN PORTIONS OF THE EASTERN SHORES OF
MARYLAND, SOUTHERN DELAWARE, AND EXTREME SOUTHEAST NEW JERSEY.
WILL GO AHEAD AND ISSUE A WINTER WEATHER ADVISORY FOR CAROLINE
AND TALBOT COUNTIES FOR 2 INCHES OF SNOW. WILL ALSO HOLD ON TO
THE WINTER STORM WATCH FOR SUSSEX COUNTY (DE) AS ALTHOUGH THE
MOST LIKELY SCENARIO IS FOR 2 TO 4 INCHES OF SNOW, WHICH IS
ADVISORY CRITERIA, CANNOT RULE OUT THE POSSIBILITY FOR 5 INCHES,
WHICH WOULD BE WARNING CRITERIA. IF THE LOW TAKES A LITTLE BIT
MORE OF A WESTERN TRACK, THEN ADVISORY LEVEL SNOW WOULD BE
POSSIBLE FOR CAPE MAY COUNTY AS WELL. BUT CONFIDENCE REMAINS TOO
LOW FOR THAT TO HAPPEN.
SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/
COLD AND BLUSTERY TO CLOSE OUT THE WEEK AS HIGH PRESSURE BUILDS
IN FROM THE WEST. FORTUNATELY, THE HIGH WILL BE WEAKENING AS IT
DOES SO, AND WANING COLD ADVECTION WILL ALLOW FOR SOME AIRMASS
MODIFICATION ON FRIDAY UNDER MOSTLY SUNNY SKIES.
EXPECTED AFTERNOON HIGHS ON FRIDAY TO TOP OUT IN THE MID TO
UPPER 30S IN MANY AREAS, WITH MANY AREAS SOUTH OF I-78 CLIMBING
ABOVE FREEZING FOR THE FIRST TIME SINCE MONDAY. NIGHT TIME LOWS
WILL STILL BE BELOW NORMAL, RANGING FROM THE MID TEENS TO NEAR
20 DEGREES.
FOR THURSDAY NIGHT THROUGH AT LEAST THE FIRST HALF OF FRIDAY,
CONDITIONS WILL BE QUITE BREEZY AS THE PRESSURE GRADIENT
STRENGTHENS. NORTHWEST WINDS NEAR 15-20 MPH WITH GUSTS IN THE
30-35 MPH RANGE. THE WINDS WILL PRODUCE SINGLE DIGIT WIND CHILLS
THURSDAY NIGHT, WITH MAXIMUM CHILLS ONLY IN THE 20S ON FRIDAY.
WINDS WILL BE LESSENING FOR FRIDAY NIGHT, BUT STILL A BREEZE
BLOWING WITH WIND CHILLS CLOSER TO 10 DEGREES.
LONG TERM /SATURDAY THROUGH TUESDAY/
SUMMARY...THE COLD EASES AS IT TURNS MILDER OVER THE WEEKEND
AND ESPECIALLY EARLY NEXT WEEK.
SYNOPTIC OVERVIEW...AN UPPER-LEVEL TROUGH SHIFTS TO OUR EAST
LATER FRIDAY WITH SOME WEAK RIDGING BRIEFLY SLIDING ACROSS OUR
AREA. A SHORTWAVE TROUGH THEN MOVES THROUGH SATURDAY, FOLLOWED
BY ANOTHER UPPER-LEVEL TROUGH POTENTIALLY ARRIVING DURING EARLY
NEXT WEEK. AT THE SURFACE, HIGH PRESSURE BUILDS OVER OUR AREA
LATER FRIDAY INTO SATURDAY BEFORE WEAKENING AND SHIFTING TO OUR
SOUTHWEST. A WEAK COLD FRONT OR SURFACE TROUGH MAY MOVE THROUGH
SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE MOVING ACROSS THE GREAT
LAKES MONDAY INTO TUESDAY SHOULD PULL A WARM FRONT TO OUR
NORTH, WITH A SURFACE TROUGH OR WEAK COLD FRONT APPROACHING FROM
THE WEST DURING TUESDAY.
FOR SATURDAY AND SUNDAY...THE FLOW ALOFT IS MORE ZONAL SATURDAY
AND WITH SURFACE HIGH PRESSURE WEAKENING SOME AND SETTLING WELL
TO OUR SOUTHWEST, A SHORTWAVE TROUGH MAY QUICKLY SLIDE ACROSS
OUR AREA SATURDAY NIGHT. SOME GUIDANCE IS A BIT SHARPER WITH
THIS FEATURE AND THEREFORE OFFERS SOME LIGHT PRECIPITATION,
HOWEVER THERE IS SOME UNCERTAINTY WITH THIS. FOR NOW, OPTED TO
KEEP THE FORECAST DRY THROUGH THE WEEKEND. GIVEN THE CORE OF THE
COLD AIR HAS RETREATED WELL TO OUR NORTH AND NORTHEAST, A
MILDER PATTERN WILL RESULT IN HIGH TEMPERATURES INCREASING SOME
EACH DAY WITH WIDESPREAD 40S FORECAST FOR SUNDAY AFTERNOON.
FOR MONDAY AND TUESDAY...AN UPPER-LEVEL TROUGH MAY AMPLIFY
EASTWARD FROM SOUTH-CENTRAL CANADA TO THE OHIO VALLEY. THIS
WOULD SUPPORT SURFACE LOW PRESSURE IN THE VICINITY OF THE GREAT
LAKES REGION AS IT TRACKS EASTWARD. A WARM FRONT SHOULD BE
LIFTING NORTH OF OUR AREA OR ALREADY BE TO OUR NORTH, THEN A
TROUGH OR WEAK COLD FRONT MAY ARRIVE TUESDAY. AS OF NOW THIS
FEATURE MAY BE MORE OF A CLIPPER-TYPE SYSTEM WITH LIMITED
MOISTURE, HOWEVER THERE IS PLENTY OF TIME FOR THIS SCENARIO TO
CHANGE WITHIN THE SUITE OF MODEL GUIDANCE INCLUDING THE NATIONAL
BLEND OF MODELS OUTPUT. EITHER WAY, THE PATTERN LOOKS TO FAVOR
A MILDER ONE DURING THIS TIME WITH HIGH TEMPERATURES REACHING OR
TOPPING 50F BOTH AFTERNOONS FOR PORTIONS OF OUR AREA.
AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR. W-NW WINDS 15 TO 20 KT WITH 25 TO 30 KT
GUSTS, GRADUALLY DIMINISHING TO LESS THAN 10 KT AFTER 06Z. HIGH
CONFIDENCE.
WEDNESDAY...VFR. W-NW WINDS 5 TO 10 KT. HIGH CONFIDENCE.
WEDNESDAY NIGHT...SUB-VFR LIKELY IN SN AT KMIV/KACY. OTHERWISE,
VFR. N WINDS 5 TO 10 KT. MODERATE CONFIDENCE.
OUTLOOK...
THURSDAY...SUB-VFR POSSIBLE IN SHOW SHOWERS IN THE AFTERNOON.
NORTHWEST WINDS 10-15 KNOTS WITH 20-25 KNOTS GUSTS.
THURSDAY NIGHT AND FRIDAY...VFR. GRADUALLY DECREASING CLOUD
COVER THURSDAY NIGHT. NORTHWEST WIND GUSTS UP TO 30 KNOTS.
SATURDAY AND SUNDAY...VFR OVERALL WITH LIGHTER WINDS.
MARINE
SMALL CRAFT ADVISORY CONDITIONS IN EFFECT FOR THE OCEAN FOR
MOST OF TONIGHT FOR NW WINDS 15 TO 20 KT WITH 25 TO 30 KT GUSTS.
CONDITIONS SUBSIDE TO SUB-SCA CRITERIA THROUGH THE NIGHT.
SUB-SCA CONDITIONS FOR WEDNESDAY AND WEDNESDAY NIGHT. VSBY
RESTRICTIONS IN SN DEVELOPING WEDNESDAY NIGHT, ESPECIALLY FOR
SOUTHERN OCEAN WATERS.
OUTLOOK...
THURSDAY...SMALL CRAFT ADVISORY CONDITIONS POSSIBLE DUE TO
NORTHWEST WINDS INCREASING TO 15-20 KNOTS WITH GUSTS UP TO 25
KNOTS.
THURSDAY NIGHT AND FRIDAY...INCREASING NORTHWEST WINDS TO NEAR
20-30 KTS WITH GUSTS OF 30-40 KTS. THE STRONGEST WINDS ARE
EXPECTED TOWARD THE SOUTH, ESPECIALLY ACROSS DELAWARE BAY AND
ADJACENT OCEAN WATERS. THE GALE WATCH WAS UPGRADED TO A GALE
WARNING FOR THESE AREAS FROM THURSDAY EVENING THROUGH FRIDAY
MORNING, AND THE WATCH REMAINS IN EFFECT ELSEWHERE. LIGHT
FREEZING SPRAY LIKELY THURSDAY NIGHT INTO FRIDAY MORNING.
SATURDAY AND SUNDAY...THE CONDITIONS ARE ANTICIPATED TO BE
BELOW SMALL CRAFT ADVISORY CRITERIA.
PHI WATCHES/WARNINGS/ADVISORIES
PA...COLD WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR PAZ054-
055.
NJ...NONE.
DE...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 6 PM EST
THURSDAY FOR DEZ003-004.
MD...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 6 PM EST
THURSDAY FOR MDZ019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
ANZ430-431-450>455.
GALE WARNING FROM 6 PM THURSDAY TO 10 AM EST FRIDAY FOR ANZ430-
431-453>455.
GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
ANZ450>452.
SYNOPSIS...GORSE
NEAR TERM...MPS/MJL
SHORT TERM...STAARMANN
LONG TERM...GORSE/STAARMANN
AVIATION...GORSE/MPS
MARINE...GORSE/MPS
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