805
FXUS61 KPHI 050721
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
321 AM EDT WED AUG 5 2026
WHAT HAS CHANGED
UPDATED ALL SECTIONS.
KEY MESSAGES
1. A WARM FRONT AND ASSOCIATED LOW PRESSURE WILL LIFT ACROSS THE
AREA TODAY CREATING UNSETTLED CONDITIONS.
2. FOR THE LATER HALF OF THE WEEK, WE WILL HAVE A HOT, HUMID,
AND AT TIMES STORMY PATTERN IN PLACE.
DISCUSSION
KEY MESSAGE 1...A WARM FRONT AND ASSOCIATED LOW PRESSURE WILL
LIFT ACROSS THE AREA TODAY CREATING UNSETTLED CONDITIONS.
A WARM FRONT WILL CONTINUE LIFTING NORTH THROUGH THE REGION THIS
MORNING. A WEAK AREA OF LOW PRESSURE ATTACHED TO THE FRONT WILL
ALSO ADD SOME MORE LIFT TO THE SYNOPTIC SITUATION THIS AFTERNOON.
INCREASING SOUTHERLY FLOW THRU TODAY WILL PUSH DEW POINTS UP INTO
THE LOW TO MID 70S THIS AFTERNOON. WITH HIGHS IN THE LOW TO MID
80S, MAX HEAT INDEX VALUES WILL BE IN THE UPPER 80S TO LOW 90S.
IN TERMS OF PRECIPITATION, SOME SHOWERS WILL DEVELOP IN THE MORNING
WITH THE PASSAGE OF THE WARM FRONT, AND THEN ANOTHER ROUND OF SHOWERS
AND SCATTERED THUNDERSTORMS WILL DEVELOP IN THE AFTERNOON. THE PRIMARY
CONCERN IS FOR HEAVY RAIN LEADING TO FLASH FLOODING, BUT WHEN IT
COMES TO A HOT AND HUMID AIRMASS, A FEW STRONG TO SEVERE THUNDERSTORMS
CANNOT BE RULED OUT.
THE WEATHER PREDICTION CENTER HAS A MARGINAL RISK (1 OUT OF 4) FOR
EXCESSIVE RAIN FOR TODAY. RAINFALL AMOUNTS WILL BE LIGHT IN THE MORNING.
WHILE OVERALL BASIN AVERAGES WILL GENERALLY BE 1/4 TO 1/2 INCH OF
RAIN, THERE IS THE POTENTIAL FOR TRAINING LEADING TO LOCALIZED RAINFALL
TOTALS IN EXCESS OF 1 INCH. WITH MOST OF THAT RAIN OCCURRING IN THE
AFTERNOON, THAT CREATES THE POTENTIAL FOR FLASH FLOODING.
KEY MESSAGE 2...FOR THE LATER HALF OF THE WEEK, WE WILL HAVE A
HOT, HUMID, AND AT TIMES STORMY PATTERN IN PLACE.
EXPECT A PROLONGED PERIOD OF SOUTHWESTERLY FLOW AS OUR REGION WILL
BE IN BETWEEN A BERMUDA HIGH WELL TO OUR EAST, AND A MID-LEVEL
LONG WAVE TROUGH THAT WILL BE SLOWLY SLIDING EAST OVER THE NORTHERN
TIER OF THE U.S./SOUTHERN CANADA. AS SUCH, IT WILL BE HOT AND HUMID
FOR THE LATER HALF OF THE WEEK AND WEEKEND WITH MAXIMUM TEMPERATURES
EACH DAY RANGING FROM THE LOW 80S (POCONOS) TO THE LOW 90S (METRO).
HOWEVER, WITH DEWPOINTS FROM 70F TO 75F, HEAT INDEX VALUES AT OR
ABOVE 100 DEGREES ARE POSSIBLE FOR MUCH OF THE AREA.
THE OTHER ASPECT OF THIS ARE THE DAILY STORM CHANCES, PRIMARILY
CONFINED TO THE AFTERNOON AND EVENING WITH A TYPICAL DIURNAL PATTERN.
GIVEN THE HOT AND HUMID CONDITIONS THAT WILL BE IN PLACE, WE CAN'T
RULE OUT THE MORE COMMON THUNDERSTORM HAZARDS OF DAMAGING WINDS
AND HEAVY RAIN/FLOODING. IF AN EMBEDDED SHORT WAVE TROUGH CROSSES
OUR REGION AS THE LARGER TROUGH AXIS APPROACHES, THAT COULD INCREASE
THE RISK, PARTICULARLY FOR SEVERE THREATS, BUT TRYING TO TIME THAT
OUT AT THIS POINT WOULD BE VERY DIFFICULT, GIVEN THAT WE ARE STILL
SEEING SOME DIFFERENCES BETWEEN THE MODELS WITH THE LARGER PATTERN.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...MVFR OR SOME HIGH-END IFR CONDITIONS MUCH OF THE DAY. SHRA
IN THE MORNING, THEN SHRA AND TSRA IN THE AFTERNOON. THERE COULD
BE PERIODS OF VFR BETWEEN THE SHOWERS. SE WINDS LESS THAN 10 KT.
LOW CONFIDENCE.
TONIGHT...CONDITIONS MAY RETURN BACK TO VFR BEHIND THE BATCH OF
SHOWERS/TSTMS IN THE EARLY EVENING. LIMITED CONFID. PATCHY FOG
MAY DEVELOP TOWARDS MORNING. LOW CONFID.
OUTLOOK...
THURSDAY THROUGH SUNDAY...PERIODS OF MVFR OR LOWER IN AFTERNOON
AND EVENING SHRA/TSRA.
MARINE
SUB-SMALL CRAFT ADVISORY CONDITIONS TODAY. EAST WINDS 10 TO 15
KT BECOME SOUTHEAST LESS THAN 10 KT, THEN WINDS BECOME SOUTH
THIS AFTERNOON AT 10 TO 15 KT. SEAS WILL AVERAGE 2 TO 3 FEET.
SCATTERED SHOWERS ARE EXPECTED THIS MORNING WITH AREAS OF FOG
TOO. SHOWERS AND THUNDERSTORMS WILL DEVELOP AGAIN THIS AFTERNOON
AND LAST INTO THE EARLY EVENING.
OUTLOOK...
WEDNESDAY NIGHT THROUGH SUNDAY...OVERALL, A PROLONGED PERIOD OF
SUB-SCA CONDITIONS, HOWEVER THERE IS A CHANCE FOR 25+ KT WIND
GUSTS THURSDAY NIGHT. AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE AS WELL.
RIP CURRENTS...
FOR TODAY, WINDS BECOMING SOUTHEASTERLY NEAR 10 MPH. BREAKING
WAVES IN THE SURF ZONE OF 1-3 FEET ARE FORECAST WITH A MEDIUM
PERIOD SWELL. GIVEN THE MORE ONSHORE COMPONENT FOR MOST OF THE
JERSEY SHORE, MAINTAINED A MODERATE RISK FOR THE DEVELOPMENT OF
DANGEROUS RIP CURRENTS. BREAKING WAVES LOOK TO BE A LITTLE LOWER
FOR THE DELAWARE BEACHES WITH A MORE PARALLEL WIND THEREFORE WENT
WITH A LOW RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS.
FOR THURSDAY, SOUTH TO SOUTH-SOUTHWEST WINDS INCREASE TO 10-20 MPH.
DESPITE THE INCREASING WIND AND IT BECOMING MORE PARALLEL TO THE
COAST AND THE BREAKING WAVES FORECAST TO BE A LITTLE LOWER, A
LONGER PERIOD SWELL MAY ARRIVE. OPTED TO GO WITH A MODERATE RISK
FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR THE JERSEY SHORE,
AND A LOW RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR
THE DELAWARE BEACHES.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...PHI
AVIATION...PHI
MARINE...PHI
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