


Area Forecast Discussion
Issued by NWS Mt. Holly, NJ
Issued by NWS Mt. Holly, NJ
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-- Discussion containing changed information from previous version are highlighted. --665 FXUS61 KPHI 152033 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 433 PM EDT Tue Jul 15 2025 .SYNOPSIS... A very warm and humid airmass will be over the region this week with multiple rounds of showers and thunderstorms expected. A cold front will stall within the vicinity of the area through Wednesday before lifting back northward as a warm front on Thursday. A cold front passes through the region on Friday with high pressure building in on Saturday. Another cold front approaches late in the weekend, lingering through the early part of the week. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... A weak boundary continues to sit over Delmarva into southern NJ and this boundary along with daytime heating and sea/bay breezes is helping to trigger some scattered convection over portions of southern DE into coastal NJ. The threat for severe weather with any of these storms is low but there is a risk of localized flash flooding as PWATS remain very high (around 2 inches) and storms are slow moving. The limiting factors for today though are that the forcing is very weak and there is a mid level dry air...especially as you head farther north towards the I-95 corridor and points northward. For this reason, storms will will continue to be isolated to scattered and be confined primarily to our southern zones. Farther north it will continue to be warm and humid with a mix of sun and clouds. Today`s convection should begin to wane and diminish around sunset with the loss of diurnal heating. Perhaps a few showers can linger into the overnight hours, but primary threat will come to a close. Skies should be mostly clear early, but an increase in clouds is expected overnight as another round of low stratus may develop after midnight. Another warm night is expected, with lows mainly in the low to mid 70s; upper 60s in the Poconos. Wednesday will start dry but as we get into the afternoon there will be some shortwave energy approaching from the west and this will help trigger another round of convection which is expected to be more widespread than today. Unlike today, the highest chances for showers/storms look to be focused near and north of the urban corridor where we have POPs of 60 to 70 percent. Unfortunately, this includes the areas that were hard hit yesterday. Model guidance isn`t especially robust depicting widespread heavy QPF amounts but given the set up of continuing high PWATS (over 2 inches) with better forcing compared to today and a setup that will favor training and back building storms we went ahead an issued a Flood Watch for flash flooding for our counties in central and northern NJ...this includes from Mercer and Middlesex Counties northward. These areas are currently very susceptible to more flooding given yesterday`s heavy rain and flash flooding. Within this area 1 hour FFG is below an inch in places with 3 hour FFG below 2 inches. So it won`t take much for these thresholds to be reached. The severe weather threat for Wednesday continues to look relatively low however the Storm Prediction Center does now include portions of our western counties (Berks County northward through the Lehigh Valley into Carbon County) in a MARGINAL risk for severe weather. The main threat is damaging winds. Highs Wednesday look to be mainly in the mid to upper 80s with dew points in the 70s so it will be quite muggy with heat indices topping out in the middle to high 90s. Getting into Wednesday night, since the best forcing won`t be arriving until later in the day Wednesday into the evening, the convection may continue to be relatively widespread through much of the evening before diminishing later at night. For this reason, we ran the Flood Watch to 3 AM Thursday. However the threat for severe weather will have diminished by the late evening. It will be another warm and muggy night with lows mostly in the 70s (60s over the Pocono Plateau). && .SHORT TERM /THURSDAY THROUGH FRIDAY/... On Thursday, southwesterly flow will bring back warm air and moisture advection resulting in heat index values approaching 100 degrees in many areas. This is anticipated to be the warmest day of the week (unless the cold front on Friday is later than currently expected). A Heat Advisory will need to be considered for Thursday across portions of the area in a future update. There will again be chances of diurnally driven showers and thunderstorms on Thursday, again focused mainly northwest of I-95. Synoptic forcing is again not very strong, and deep layer shear will be weak. A lot of uncertainty regarding the convective environment for Thursday, and we currently have no threats outlooks by WPC or SPC but this could change especially on the hydrology side of things given how wet it has been within the area of highest PoPs. PoPs are mostly 40-80%, with the highest probabilities north and west of Philadelphia. Thursday night will be the warmest night of the week, with low temperatures mainly in the mid to upper 70s and should be mainly dry. Friday could be another hot day depending on the timing of the next cold front. Latest guidance shows the front crossing through the region late in the day, and into the overnight hours on Friday. If that timing holds, most of the area (aside from Delmarva) may be a degree or two lower on Friday as compared to Thursday. This front may also act as a focusing mechanism for thunderstorms and associated convective hazards, but as with Thursday, uncertainty is high regarding any of these threats. PoPs are near 20-50% for much of the area. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... Heading into the weekend, Saturday should experience the lowest chance of convection with a surge of slightly drier air, lower instability, and some subsidence from the departing trough. Temperatures returning back closer to normal, and a comparatively nice Saturday looks to be shaping up with highs in the mid 80s and lower humidity compared to this week. Chances for convection should increase again some for Sunday as the boundary start lifting north with return flow. Unsettled conditions look to hang around through the start of next week with the boundary lingering over the area, though too early to say if any impactful severe weather or flood threat will come into play. Temperatures to start next week look to be near seasonal norms. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Rest of this afternoon...mainly VFR except some convection occuring around ILG, MIV, and ACY could result in brief restrictions if if moves over one of these sites. Confidence is low on this. And farther north any convection will be even more isolated so no mention of TS or VCTS in TAFs for today. SW winds around 5 knots. Low to moderate confidence. Tonight...mainly VFR this evening with the potential for a low cloud deck to once again form for the overnight bringing cig restrictions. Confidence is low on this but the best chances for this occuring appear to be from the I-95 TAF sites southward. Low confidence. Wednesday...Mainly VFR in the morning (following any early morning low stratus) with showers/storms developing in the afternoon and lasting into Wednesday night. These storms are expected to be more widespread than what`s occuring today so will have a better chance of bringing more widespread restrictions to TAF sites by later in the day. SW winds around 5-10 knots with some gusts to 15-20 knots possible. Moderate confidence. Outlook... Thursday...Primarily VFR, though MVFR/IFR conditions possible (20- 40%) as some showers and thunderstorms develop in the afternoon, with the highest probability for restrictions coming for KABE/KRDG. Thursday Night...VFR. No significant weather. Friday...Primarily VFR, though restrictions possible (15-30%) with scattered showers and thunderstorms around in the afternoon. Friday Night...VFR. No significant weather. Saturday through Saturday Night...Primarily VFR. Isolated showers around in the afternoon and early evening. Sunday...Primarily VFR but restrictions possible (40-50%) with showers and thunderstorms developing in the afternoon. && .MARINE...-- Changed Discussion --No marine headlines are in effect through tonight as SW winds will be around 10 knots through this period. Scattered showers and thunderstorms possible through tonight, which may cause locally gusty winds in excess of 34 kt. Late day Wednesday into Wednesday night southwest winds increase to around 15 to 20 with gusts of 20 to 25 knots possible. So a Small Craft Advisory may be needed though it will be marginal. Outlook... Thursday...Sub-SCA conditions expected, though cannot rule out a few gusts near 25 kt. 15% chance an SCA is needed. Seas 2 to 4 feet. Thursday Night through Sunday...No marine headlines expected. Periods of showers and thunderstorms expected, mainly in the afternoon and evening most days. Rip Currents... On Wednesday, south to southwest winds will increase to around 10 mph, with a few gusts to 20 mph possible. Breaking waves will generally be 1 to 2 feet with an easterly swell around 8 seconds. There is a LOW risk for the development of dangerous and life threatening rip currents for the Jersey Shore and for Delaware Beaches. On Thursday, southwest winds will once again be around 10 to 15 mph with breaking waves 1 to 2 feet and an easterly swell around 8 seconds. This results in a LOW risk for the development of dangerous and life threatening rip currents for the Jersey Shore and for Delaware Beaches. Rip currents occur often in the vicinities of jetties and piers and the speed of the currents are generally maximized at low tides. For specific beach forecasts, visit weather.gov/beach/phi-- End Changed Discussion --&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...Flood Watch from Wednesday afternoon through late Wednesday night for NJZ001-007>010-012-015. DE...None. MD...None. MARINE...None. && $$ SYNOPSIS...DeSilva/Hoeflich NEAR TERM...DeSilva/Fitzsimmons SHORT TERM...Hoeflich/Johnson/Staarmann LONG TERM...Hoeflich/Johnson/Staarmann AVIATION...Fitzsimmons/Hoeflich MARINE...Fitzsimmons/Hoeflich/MPS