


Area Forecast Discussion
Issued by NWS Mt. Holly, NJ
Issued by NWS Mt. Holly, NJ
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-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --079 FXUS61 KPHI 150020 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 820 PM EDT Mon Jul 14 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 move eastward into the region through tonight, and then stall near or just south of our area through Wednesday. It will move northward as a warm front on Thursday. Another cold front approaches toward the end of week. && .NEAR TERM /THROUGH TUESDAY/...-- Changed Discussion --Ongoing flash flooding and some river/creek flooding across the region as the slow moving front crosses through. Infrequent severe warnings too with a few downbursts, but only a few earlier. Continue to monitor the latest warnings for your area and take action as needed. The rains will continue well into the early overnight and then diminish. Warm and humid conditions for the remainder of the overnight with low clouds and some fog too. Gusty winds in tstms, but light variable winds following. Please contact our office or post on social media and damage or pictures of flooding, only if you can do so safely. Latest guidance depicts the front stalling just south of our region. If this comes to fruition, that would mean the main focus for storms tomorrow will be south and east of our region. That being said, there is still uncertainty if the front will make it that far south. In the area of the front, expect another round of potential heavy rain. One thing that is different tomorrow (as compared to today) is the mid and upper level pattern will be characterized by short wave ridging instead of the trough that is crossing over today. Consequently, coverage of storms, even in the area of the front will be far more limited. Even if the front is fully south of our area, it is weakening, so don`t expect any significant dry or cold air advection in its wake.-- End Changed Discussion --&& .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... Unsettled weather along with very warm and humid conditions will continue through Thursday. Several rounds of showers and thunderstorms can be expected, with locally heavy rainfall leading to flash flooding being the primary threat. On Thursday, there is also a concern for extreme heat. The front may begin to lift north on Wednesday, but its exact placement remains uncertain at the moment. The shortwave ridge will still be overhead on Wednesday, and this could act to introduce some dry mid level air into the equation. Synoptic forcing will not be strong, and shear will again be weak. At least scattered showers and thunderstorms should develop again into the afternoon and evening due to the diurnal instability and lack of any significant subsidence or CIN. PoPs remain around 50- 70% for our inland areas. No severe probabilities are currently included from SPC, but there could be an isolated damaging wind gust from any stronger thunderstorms that develop. PWats will again by high around 2" or so, so the tropical downpours will also remain a threat. On Thursday, southwesterly flow will bring back warm air and moisture advection resulting in heat index values approaching 100 degrees in many areas. This could be the warmest day of the week (unless the cold front on Friday is later than currently expected). && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... 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. 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. Chances for convection should increase again some for Sunday as the boundary start lifting north with return flow. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/...-- Changed Discussion --The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...Sub-VFR in SHRA/TSRA in the evening. Sub-VFR conditions in fog and stratus possible thereafter. Low confidence. Tomorrow...Prevailing VFR. scattered TSRA possible after 18Z, which could result in brief MVFR conditions. Outlook... Wednesday through Saturday...Overall, prevailing VFR conditions. However, afternoon and evening SHRA/TSRA may result in brief restrictions daily. Restrictions conditions are also possible overnights/early mornings due to low clouds and fog, but uncertainty remains on this potential, so confidence is low on any daily details.-- End Changed Discussion --&& .MARINE... Winds and seas should generally stay below Small Craft Advisory criteria through tonight. Gusty winds could be possible in the vicinity of any thunderstorms late today/this evening. Outlook... Wednesday through Saturday...Winds and seas should stay below Small Craft Advisory criteria through this period. Showers and thunderstorms are possible daily, primarily in the late afternoon and evening hours. Rip Currents... Tuesday, southerly winds 5-10 mph with breaking waves around 1 to 2 feet. This combined with an easterly swell around 1 foot at 6-7 seconds in length will result in a LOW risk for the development of dangerous and life threatening rip currents at all beaches. Wednesday, south-southwesterly winds 5-10 mph with breaking waves around 1 to 2 feet. This combined with an easterly swell around 1 foot at 6-8 seconds in length will result in a continued LOW risk for life threatening rip currents at all 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 && .HYDROLOGY... As mentioned above, there is a risk for heavy rain leading to flash flooding with any showers and storms through this evening. The flood watch remains in effect for much of our region. There are a lot of factors that are increasing our risk for flash flooding. Soundings depict a tall, skinny CAPE profile typical of a heavy rain pattern. Precipitable water on the 12Z KIAD sounding was above 2 inches. This is well above the 90th percentile for this time of year. Additionally, the warm cloud layer should be quite deep. Storm motions, although slightly faster than what we have seen the last several days, will still be relatively slow (around 20 to 30 mph) The only factors not present that typically are with heavy rain events is that wind shear will be weaker than typical (near or below 10 kt), and there doesn`t look like there will be much of a low level jet for moisture transport. This could limit how long individual cells last before dissipating. The biggest concern is for flash flooding on roadways, in urban areas, and for small streams and creeks. What areas have flash flooding will be highly dependent on where the heaviest downpours set up. Significant main stem river flooding is not expected. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...Flood Watch until 2 AM EDT Tuesday for PAZ054-055-060>062-070- 071-101>106. NJ...Flood Watch until 2 AM EDT Tuesday for NJZ001-007>010-012-013- 015>019. DE...Flood Watch until 2 AM EDT Tuesday for DEZ001. MD...Flood Watch until 2 AM EDT Tuesday for MDZ012-015-019-020. MARINE...None. && $$ SYNOPSIS...Johnson/Staarmann NEAR TERM...RCM/PO SHORT TERM...Johnson/Staarmann LONG TERM...Johnson/Staarmann AVIATION...Johnson/RCM/Staarmann/PO MARINE...Johnson/RCM/Staarmann HYDROLOGY...