715
FXUS61 KPHI 260606
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
206 AM EDT SAT APR 26 2025
SYNOPSIS
A WARM FRONT WILL LIFT NORTH ACROSS THE MID ATLANTIC THIS EVENING
FOLLOWED BY A COLD FRONT ON SATURDAY. HIGH PRESSURE WILL BUILD IN
BEHIND THE LOW PRESSURE SYSTEM FOR SUNDAY AND PERSIST THROUGH
TUESDAY. A COLD FRONT IS EXPECTED ON WEDNESDAY. MORE HIGH PRESSURE IS
EXPECTED THURSDAY AND FRIDAY.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE: ROUNDS OF SHOWERS AND STORMS, WITH A FOCUS ON A
LINE OF STORMS JUST AHEAD OF THE COLD FRONT THIS
AFTERNOON/EVENING THAT COULD BRING LIGHTNING AND SOME GUSTY
WINDS.
WHAT HAS CHANGED: INCREASING CONCERN FOR A POTENTIAL OF GUSTY
WINDS WITH THE LINE OF STORMS JUST AHEAD OF THE COLD FRONT,
PRIMARILY FOR THE COASTAL PLAIN.
DETAILS: AN INITIAL ROUND OF SHOWERS, MOSTLY SCATTERED OR
ISOLATED IN COVERAGE, IS PROGRESSING THROUGH THE REGION NOW.
MODEL SOUNDINGS SHOW VERY LIMITED ELEVATED INSTABILITY WITH THIS
INITIAL ROUND, SO HAVE KEPT A MENTION OF ISOLATED THUNDERSTORMS
FOR NOW, THOUGH THERE REALLY HASN'T BEEN ANY LIGHTNING OVER THE
LAST 2 HOURS.
THIS INITIAL ROUND OF SHOWERS IS EXPECTED TO CONTINUE (OFF AND
ON) THROUGH MID DAY, THOUGH SOME MODELS DEPICT A DRY SLOT
WORKING INTO PORTIONS OF THE COASTAL PLAINS, SO THOSE AREAS MAY
HAVE A LONGER LULL.
THE MAIN FOCUS IN THIS PERIOD WILL BE THE SECOND ROUND OF
SHOWERS AND THUNDERSTORMS EXPECTED JUST AHEAD OF THE COLD FRONT
THIS AFTERNOON. WITH THIS ROUND, EXPECTING A LINE OF SHOWERS AND
STORMS TO PROGRESS QUICKLY FROM WEST TO EAST THROUGH THE
AFTERNOON AND EVENING (APPROXIMATELY 1 PM TO 8 PM).
THERE IS INCREASING CONCERN THAT THERE WILL BE A THREAT FOR
GUSTY WINDS WITH THIS SECOND ROUND OF STORMS, ESPECIALLY FOR
AREAS ALONG AND EAST OF THE INTERSTATE 95 CORRIDOR. MODEL
SOUNDINGS DEPICT A BRIEF WINDOW OF A LONG AND SKINNY CAPE
PROFILE. WHILE THE CAPE VALUES WILL BE LIMITED, IT COULD BE
ENOUGH TO MIX DOWN SOME OF THE STRONGER WINDS ALOFT.
ADDITIONALLY, A LAYER OF DRY AIR BETWEEN 700 AND 500 MB COULD
LEAD TO SOME DRY AIR ENTRAINMENT AND POTENTIAL FOR DOWNBURSTS.
MODEL DCAPE VALUES IN MANY AREAS ARE HIGHER THAN THE CAPE
VALUES.
IN THE WAKE OF THE COLD FRONT, SHOWERS WILL CLEAR OUT QUICKLY,
AND WINDS WILL INCREASE OUT OF THE NORTHWEST. EXPECT TO STAY
RELATIVELY WELL MIXED OVERNIGHT, BUT WITH STRONG COLD AIR
ADVECTION IN THE WAKE OF THE COLD FRONT, SHOULD STILL BE ABLE TO
DROP DOWN INTO THE 30S AND 40S FOR MOST OF THE AREA.
SHORT TERM /SUNDAY THROUGH MONDAY/
THE PERIOD BEGINS WITH MID-LEVEL LOW PRESSURE TO OUR NORTH. AT THE
SURFACE, A COLD FRONT WILL BE JUST TO OUR EAST. THIS COLD FRONT WILL
CONTINUE TO TRACK OFFSHORE WITH A TIGHTENING GRADIENT BEHIND IT.
SHOWERS WILL BE COMING TO AN END ON SATURDAY NIGHT. A GOOD AMOUNT OF
SUNSHINE WILL BE IN PLACE ON SUNDAY, ESPECIALLY ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. DEFINITELY MORE CLOUDS TO THE NORTH.
THE MID-LEVEL LOW WILL PUSH OFF TO OUR NORTHEAST SUNDAY NIGHT. AT
THE SURFACE, HIGH PRESSURE WILL BEGIN TO BUILD IN. WHILE THE MID-
LEVEL NW FLOW WILL PERSIST ON MONDAY, THE SURFACE HIGH WILL PASS
OVERHEAD AND CENTER ITSELF JUST OFF THE COAST LATE ON MONDAY.
AFTER A BREEZY DAY ON SUNDAY, WINDS WILL RELAX SUNDAY NIGHT AND BE
ON THE LIGHTER SIDE ON MONDAY.
SATURDAY AND SUNDAY NIGHT LOWS WILL WILL BE SIMILAR WITH THE UPPER
30S IN THE SOUTHERN POCONOS AND IN THE 40S EVERYWHERE ELSE.
SUNDAY WILL BE THE COOLER DAY OF THE WEEKEND IN THE POST-FRONTAL
ENVIRONMENT. HIGHS WILL BE IN THE 50S ACROSS THE NORTH AND 60S
SOUTH. EXPECT 60S AND 70S ON MONDAY.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
SURFACE HIGH PRESSURE WILL REMAIN IN PLACE MONDAY NIGHT, BUT BEGIN
TO UNRAVEL ON TUESDAY. THIS WILL ALLOW A COLD FRONT TO MOVE THROUGH
THE REGION ON WEDNESDAY. WEAK SURFACE HIGH PRESSURE WILL BUILD ONCE
AGAIN THURSDAY. A WARM FRONT WILL FIRST APPROACH THE REGION ON
FRIDAY FOLLOWED BY A COLD FRONT. IN SHORT, EXPECT A COUPLE SHOTS OF
PRECIPITATION THE SECOND HALF OF THE WEEK.
OVERNIGHT LOWS MONDAY NIGHT WILL BE AROUND NORMAL. TEMPERATURES WILL
MOVE INTO THE ABOVE NORMAL CATEGORY ON TUESDAY AND STAY THERE
THROUGH MUCH OF THE WEEK. WHILE THE GUIDANCE HAS COME DOWN FROM ITS
EARLIER PEAK IN THE MID TO UPPER 80'S ON TUESDAY AND/OR WEDNESDAY,
LOWER 80S STILL LOOK REASONABLE. THURSDAY'S TEMPERATURES LOOK
NORMAL. FRIDAY COULD MOVE ABOVE NORMAL.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...STARTING VFR. EXPECT PERIODS OF MVFR OR EVEN IFR
TO DEVELOP, THOUGH THUS FAR, THEY HAVE BEEN MUCH SLOWER TO
DEVELOP THAN WHAT MOST GUIDANCE WAS DEPICTING. THUS, HAVE GONE
MOSTLY HIGHER THAN GUIDANCE THROUGH THE OVERNIGHT PERIOD. SOME
VISIBILITY RESTRICTIONS POSSIBLE WITH SHOWERS, BUT EXPECT THE
CONTROLLING FACTOR TO BE THE CEILINGS. WINDS GENERALLY OUT OF
THE SOUTH AROUND 10 KT. LOW CONFIDENCE.
TODAY...PERIODS OF MVFR CONDITIONS (MOSTLY DUE TO CEILINGS)
WILL BE POSSIBLE. ALTHOUGH SHOWERS WILL BE POSSIBLE THROUGH THE
DAY, THE MAIN PERIOD OF CONCERN FOR THUNDERSTORMS WILL BE THE
LAST ROUND OF SHOWERS AND THUNDERSTORMS EXPECTED TO MOVE FROM W
TO E BETWEEN 18 AND 00Z. ONCE THIS ROUND (AND THE ASSOCIATED
COLD FRONT PASSES), EXPECT A QUICK RETURN TO VFR AND AN ABRUPT
WIND SHIFT TO NORTHWESTERLY WINDS WITH GUSTS UP TO 25KT.
TONIGHT...VFR CONDITIONS EXPECTED WITH NORTHWESTERLY WINDS
CONTINUING TO GUST NEAR 20KT.
OUTLOOK...
SUNDAY THROUGH TUESDAY...VFR CONDITIONS EXPECTED. GUSTY NW
WINDS LIKELY ON SUNDAY.
TUESDAY NIGHT AND WEDNESDAY...RESTRICTIONS EXPECTED, AT LEAST MVFR.
MARINE
AFTER MIDNIGHT, A SMALL CRAFT ADVISORY WILL BE IN EFFECT FOR
ALL ATLANTIC COASTAL WATERS THROUGH SATURDAY. A SMALL CRAFT
ADVISORY WILL BE IN EFFECT FOR THE DELAWARE BAY BEGINNING AT 6
AM SATURDAY AS WELL. SOUTH-SOUTHWESTERLY WINDS WILL INCREASE TO
AROUND 17-22 KT WITH GUSTS UP TO 25-30 KT POSSIBLE WITH SEAS
BUILDING TO AROUND 4-6 FEET. SCATTERED RAIN SHOWERS AND ISOLATED
THUNDERSTORMS ARE EXPECTED AFTER MIDNIGHT CONTINUING THROUGH
THE DAY ON SATURDAY.
ALSO, PATCHY TO AREAS OF DENSE MARINE FOG ARE EXPECTED TO
DEVELOP TONIGHT INTO SATURDAY MORNING. A MARINE DENSE FOG
ADVISORY MAY BECOME WARRANTED LATER TONIGHT, IF SUCH FOG
DEVELOPS.
OUTLOOK...
SATURDAY NIGHT AND SUNDAY...AT THE MINIMUM, SCA CONDITIONS EXPECTED.
GUSTS BETWEEN 25 TO 35 KT POSSIBLE.
SUNDAY NIGHT THROUGH TUESDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY NIGHT AND WEDNESDAY...SCA CONDITIONS EXPECTED.
FIRE WEATHER
SHOWERS WILL IMPACT THE AREA TONIGHT THROUGH SATURDAY EVENING.
OVERALL, BETWEEN 1/4 AND 1/2 INCH OF RAIN WILL FALL ACROSS MOST
OF THE AREA, THOUGH UP TO AN INCH OF RAIN IS POSSIBLE IN THE
SOUTHERN POCONOS AND FAR NORTHWEST NEW JERSEY, AND 1/10 INCH OR
SO IS POSSIBLE IN DELMARVA.
ON SUNDAY, NORTHWEST WINDS WILL INCREASE TO 15 TO 20 MPH WITH 30 TO
35 MPH GUSTS POSSIBLE. IN ADDITION, RH VALUES WILL DROP BELOW 40%
SOUTH OF THE PA TURNPIKE AND 195 IN NJ. WE CAN'T RULE OUT 30 TO
35%.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT SUNDAY
FOR ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR ANZ450>455.
SYNOPSIS...KRUZDLO
NEAR TERM...JOHNSON
SHORT TERM...KRUZDLO
LONG TERM...KRUZDLO
AVIATION...KRUZDLO/JOHNSON
MARINE...COOPER/DESILVA/KRUZDLO
FIRE WEATHER...
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