756
FXUS61 KPHI 020708
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
308 AM EDT SUN AUG 2 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGE 1 AND MARINE SECTIONS.
KEY MESSAGES
1. SHOWERS AND THUNDERSTORMS INCREASE IN COVERAGE LATER TODAY
AND TONIGHT AND PERSIST INTO MONDAY. THERE IS SOME POTENTIAL
FOR AREAS OF HEAVY RAIN LEADING TO A RISK OF FLASH FLOODING.
THERE IS ALSO A RISK FOR STRONG TO SEVERE THUNDERSTORMS.
DISCUSSION
KEY MESSAGE 1... SHOWERS AND THUNDERSTORMS INCREASE IN COVERAGE LATER
TODAY AND TONIGHT AND PERSIST INTO MONDAY. THERE IS SOME POTENTIAL
FOR AREAS OF HEAVY RAIN LEADING TO A RISK OF FLASH FLOODING. THERE
IS ALSO A RISK FOR STRONG TO SEVERE THUNDERSTORMS.
AN UPPER-LEVEL TROUGH WILL SHIFT ACROSS EASTERN CANADA INTO EARLY
NEXT WEEK. WHILE THIS OCCURS, STRONG ENERGY CRESTS A RIDGE IN THE
WEST AND THIS CARVES THE TROUGH OUT MORE INTO THE TENNESSEE AND OHIO
VALLEYS TODAY AND TONIGHT. THERE CONTINUES TO BE SIGNALS IN MODEL
GUIDANCE SHOWING THIS TROUGH POTENTIALLY BECOMING CLOSED OFF INTO
EARLY NEXT WEEK AS IT GRADUALLY APPROACHES THE EAST. THE MAIN TROUGH
MAY DETACH AND DEPART TO THE NORTHEAST LEAVING BEHIND A LINGERING
CLOSED LOW. THIS SCENARIO WOULD LEAD TO THE SYSTEM SLOWING ITS
EASTWARD PROGRESSION THROUGH THE FIRST HALF OF NEXT WEEK. THE MODEL
TRENDS CONTINUE TO SHOW A SLOWER ARRIVAL OF THIS SYSTEM, WITH THE
BULK OF THE SHOWERS AND THUNDERSTORMS OCCURRING LATER TONIGHT AND
ESPECIALLY ON MONDAY.
AHEAD OF THE STRENGTHENING UPPER-LEVEL TROUGH, DEEP SOUTH TO SOUTHWEST
FLOW WILL INCREASE AND THIS WILL RAMP UP THE LOW-LEVEL MOISTURE AND
TEMPERATURE ADVECTION. IT WILL THEREFORE BE A HUMID TIME FRAME AS
THE PRECIPITABLE WATERS SURGE TO 2+ INCHES. THERE LOOKS TO BE MULTIPLE
ROUNDS OF SHOWERS AND THUNDERSTORMS, STARTING WITH AN INITIAL ROUND
LATER TONIGHT INTO MONDAY WITH THE INCREASED WARM AIR ADVECTION REGIME.
INSTABILITY WILL INCREASE, HOWEVER THE TIMING AT NIGHT SHOULD LIMIT
THE THUNDERSTORM INTENSITY ESPECIALLY SINCE IT MAY BE MORE OF ELEVATED
CONVECTION INITIALLY. AREAS OF HEAVY RAIN HOWEVER WILL BE PROBABLE
GIVEN THE INCREASING FORCING FOR ASCENT AND HIGH WATER CONTENT AIR.
WHEN LOOKING AT MODEL SOUNDINGS, THE HIGH PRECIPITABLE WATER VALUES,
WARM CLOUD LAYER PROCESSES, AND TALL SKINNY CAPE PROFILES SHOW THE
HEAVY RAIN POTENTIAL. FOR TONIGHT INTO MONDAY, THE WEATHER PREDICTION
CENTER CONTINUES WITH A MARGINAL RISK (LEVEL 1 OUT OF 4) FOR EXCESSIVE
RAINFALL.
ON MONDAY, RIPPLES OF ENERGY ALONG THE INCOMING COLD FRONT DURING
THE DAY MAY ENHANCE THE CONVECTIVE POTENTIAL AND WITH DEEP SOUTHERLY
FLOW, SOME TRAINING CONVECTION WILL BE POSSIBLE. EXCESSIVE RAINFALL
RATES WOULD ENHANCE THE FLASH FLOODING RISK, ESPECIALLY FROM THE
I-95 CORRIDOR TO THE NORTH AND WEST WHERE THE ELEVATION RISE COULD
BOOST THE ASCENT SOME GIVEN A SOUTHEAST TO SOUTH LOW-LEVEL FLOW.
THERE IS A SLIGHT RISK (LEVEL 2 OUT OF 4) FOR EXCESSIVE RAINFALL
FOR MONDAY INTO MONDAY NIGHT FOR MAINLY NORTHERN PORTIONS OF NEW
JERSEY. THERE IS A MARGINAL RISK (LEVEL 1 OUT OF 4) FOR THE REST
OF OUR AREA.
IN TERMS OF THE SEVERE WEATHER RISK, THE SPC HAS PARTS OF EASTERN
PENNSYLVANIA AND NORTHEAST MARYLAND IN A MARGINAL RISK FOR SEVERE
THUNDERSTORMS TODAY/TONIGHT. ON MONDAY, THE MARGINAL RISK MOVES
TO COVER EASTERN PENNSYLVANIA AND NORTHERN/CENTRAL NJ. THE MAIN
HAZARD FOR BOTH DAYS WILL BE DAMAGING WINDS WHICH WILL ACCOMPANY
WATER LOADED DOWNBURSTS.
BEYOND MONDAY NIGHT, THE FRONT WILL WEAKEN ACROSS THE AREA TUESDAY
AND WE'LL HAVE TO CONTINUE WITH CHANCES (25% TO 35%) FOR SHOWERS/TSTMS
ON TUESDAY WITH THE VERY WARM AND HUMID AIRMASS REMAINING IN
PLACE.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
OVERNIGHT...VFR WITH GRADUALLY LOWERING CEILINGS. ADDED SOME
SHOWERS TO KRDG/KABE AS A FEW HAVE BEEN MOVING ACROSS THOSE
AREAS AS OF LATE. THIS IS PROBABLY THE ONLY RAINS FOR THE
OVERNIGHT. SOUTHEAST WINDS 5-10 KTS. MEDIUM CONFIDENCE.
SUNDAY...VFR TO START. CEILINGS WILL CONTINUE TO GRADUALLY
LOWER, WITH MVFR CEILINGS PROBABLE FOR THE NW SITES BY LATE
AFTERNOON. VARYING GUIDANCE WITH REGARDS TO WHEN STEADY RAINS
BEGIN LIMIT OVERALL CONFID. GFS HAS PLENTY OF DAYTIME SHOWERS
ACROSS MOST SITES WHILE NAM IF DRIER DURING THE DAY. GENERALLY
BLENDED WITH PREVIOUS TAFS. AMDS PROBABLE. LOW/MEDIUM CONFID.
OUTLOOK...
SUNDAY NIGHT AND MONDAY...PERIODS OF SUB-VFR CONDITIONS ALONG WITH
SHOWERS AND THUNDERSTORMS.
TUESDAY THROUGH THURSDAY...TIMES OF SUB-VFR CONDITIONS ARE PROBABLE
AS SOME SHOWERS AND THUNDERSTORMS CONTINUE, ESPECIALLY EACH
AFTERNOON AND EVENING.
MARINE
NO MARINE HEADLINES EXPECTED THROUGH SUNDAY. SOUTH WINDS AROUND
10-15 KT WITH A FEW GUSTS UP TO 20 KTS. SEAS 2 TO 3 FEET.
OUTLOOK...
SUNDAY NIGHT AND MONDAY...A SMALL CRAFT ADVISORY WAS ISSUED EARLIER
FOR ALL OF THE NEARSHORE ATLANTIC COASTAL WATERS. WE'VE ADJUSTED
THE TIMING A BIT WITH A EARLIER STARTING TIME. SOUTH TO SOUTH-
SOUTHWEST FLOW INCREASES SUNDAY NIGHT INTO MONDAY WITH WIND GUSTS
UP TO 25 KT. SEAS ALSO INCREASE TO 4-6 FEET. SOME GUSTY THUNDERSTORMS
POSSIBLE ON MONDAY.
TUESDAY THROUGH THURSDAY...NO MARINE HEADLINES ARE ANTICIPATED.
RIP CURRENTS...
FOR TODAY, WINDS TURN MORE SOUTHEASTERLY, WHICH IS MORE
DIRECTLY ONSHORE, AND INCREASING TO AROUND 15 MPH. WHILE THERE
WILL BE A SHORT 6-7 SECOND PERIOD SWELL, GIVEN THE STRONG WINDS,
WAVE HEIGHTS IN THE SURF ZONE MAY BE UP TO 3 FEET, PARTICULARLY
AT SOUTHEASTERLY FACING BEACHES. AS A RESULT, THERE IS A
MODERATE RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR
THE BEACHES OF CAPE MAY, ATLANTIC, AND OCEAN COUNTIES OF NJ. AT
THE BEACHES OF MONMOUTH COUNTY, NJ AS WELL AS THE DELAWARE
BEACHES, THE RISK FOR SUNDAY REMAINS LOW GIVEN THAT WINDS AT
THESE BEACHES WILL BE MORE SHORE PARALLEL.
FOR MONDAY, THE RISK FOR THE DEVELOPMENT OF RIP CURRENTS
INCREASES TO MODERATE FOR ALL BEACHES. WINDS WILL BE MORE SHORE
PARALLEL OUT OF THE SOUTH-SOUTHWEST BUT INCREASING TO AROUND
15-20 MPH. ADDITIONALLY, A STRENGTHENING SWELL WILL RESULT IN
OFFSHORE SEAS OF 5-6 FEET. IN THE SURF ZONE, THIS TRANSLATES TO
BREAKING WAVES OF 2-3 FEET WITH A MEDIUM 8-9 SECOND PERIOD.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
TUESDAY FOR ANZ450>455.
DISCUSSION...PHI
AVIATION...PHI
MARINE...PHI
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