FXUS61 KPHI 261508

AFDPHI



Area Forecast Discussion

National Weather Service Mount Holly NJ

1108 AM EDT Thu Jun 26 2025



.SYNOPSIS...

The strong upper level ridge to our southwest will weaken and allow

a back door cold front to track though much of the forecast area

today through Friday. The front will then push back to the north

as a warm front on Saturday and Sunday with high pressure remaining

in control into Monday. Another cold front looks to cross through

the area on Tuesday.



&&



.NEAR TERM /THROUGH TONIGHT/...

Much of the region will see modest relief from the extreme heat of 

the past few days today thanks to a backdoor cold front moving in 

from the northeast throughout the day today. The frontal boundary 

looks to reach somewhere near or just southwest of Philadelphia by 

the afternoon, possibly stalling for a little bit, before moving 

further southwest and enveloping the while CWA tonight. As a result, 

we can expect a rather notable temperature and heat index gradient 

across the region this afternoon. Northeast of the front, afternoon 

highs will be closer to climatology with mid to upper 80s; expect 

upper 70s and low 80s across the higher elevations of the Poconos 

and northwest NJ. South and west of the boundary, afternoon 

temperature will remain rather hot with low to mid 90s, mainly 

across extreme southern NJ and the Delmarva Peninsula. Heat indicies 

will still be around 95-105 degrees south and west of the front, 

thus areas across the Delmarva Peninsula have a Heat Advisory in 

effect. 



As the backdoor front moves through the region, scattered showers 

and thunderstorms are expected to form around and along the front. 

In terms of severe weather potential, the risk is overall marginal 

across areas along and southwest of the front, mainly including the 

southeast PA, the Philly Metro, southern NJ, and the Delmarva, 

mainly thanks to CAPE values building to 1500-2500 J/kg. That said, 

overall shear will be weak, limiting severe potential. The greatest 

risk would be an isolated strong downdraft in the strongest of 

storms. In terms of flooding potential, weak storm motion and PWAT 

values around 1.75-2.00 inches would support the potential for slow-

moving thunderstorms with heavy downpours. While more of an isolated 

threat, flash flooding from a training thunderstorm is certainly 

possible. 



Tonight, isolated showers and thunderstorms may linger into the 

evening but diminish into the overnight hours. The backdoor front is 

expected to push through the rest of the region, allowing much 

cooler temperatures to arrive for everyone with lows in the 60s to 

around 70.



&&



.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...

The wavy front nearby and low pressure moving along it will keep 

clouds and showers across the area Thursday night and Friday. Friday 

will be noteworthy with high temps probably only topping out in the 

upper 60s/low 70s across the north and mid/upper 70s for Delmarva 

and south NJ. These highs are some 20 degrees less than recent days. 

We'll have mostly chance pops for showers/tstms from Thursday night 

thru Friday night with the greater chances for the N/W counties and 

lesser POPS for S/E areas. On Saturday, the fronts draw nearer and 

Likely POPs are in the grids for N/W areas with high chance pops for 

E/SE areas. Highs Sat will snap back to slightly above normal levels 

with 85 to 90 degree temps again most spots with low 80s N/W.



&&



.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

The storm track will remain nearby late this weekend and into the 

beginning/middle parts of next week. The strong ridge that has been 

across the area lately will have diminished and moved offshore. This 

will keep the extreme heat away from the area. Still, temperatures 

will be near normal Sunday followed by slightly above normal 

readings for Monday thru Wednesday. Readings are not expected to be 

record setting like this past week has been. Highs will mostly be 

upper 80s with some low 90s across the S/E areas and low/mid 80s for 

north NJ and the southern Poconos. Lows will mostly be in the upper 

60s to low 70s with some mid 70s in urban areas. 



Another result of the storm track being nearby will ensure more 

showers and clouds for the long term. There are chances for 

showers/tstms each day with Tue having the highest POPs (low likely 

range mostly) and low numbers for Wednesday when POPs are only 

slight chance attm. Upper troughing develops later next week, so 

more showers and normal temps (if not below) may arrive later next 

week. The different models offer with the degree of troughing, so 

there is uncertainty with how mild it will actually be.



&&



.AVIATION /15Z THURSDAY THROUGH MONDAY/...

Rest of today...Mainly VFR, but MVFR possible mainly from PHL

north and east as backdoor front brings stratus deck. Spotty 

showers/t-storms possible during the day especially western 

terminals. Winds turning northeasterly 5-10 kts. Low confidence.





Thursday night...Sub-VFR conditions possible. For RDG/ABE, low 

stratus possible thanks to increased chance for low level moisture 

from showers and storms earlier in the day.  For the I-95 and 

MIV/ACY, onshore flow will help bring about low stratus in addition 

to some fog for areas that see a shower or storm. Northeasterly 

winds 5-10 kts. Low confidence. 



Outlook...



Friday/Friday night...Plenty of low clouds and showers expected with 

onshore flow across the area. Mostly areas with have low-end 

MVFR with IFR strongly possible too. Further inland, (KABE,KRDG)

the CIGS may not be as low and will trend closer to VFR at 

times. 



Saturday thru Monday... Largely VFR but a few showers/tstms at times 

with lower CIGs/VSBYs expected.



&&



.MARINE...

Small Craft Advisory thru the afternoon for northernmost NJ

marine zone given northeast flow gusting 25-30 kts which likely

continues a few more hours. Rest of zones should see NE winds 

5-10 kts today into tonight behind a backdoor cold front, 

increasing to 10-15 kts with some gusts up to 20 kts. A spotty 

gusty thunderstorm possible this afternoon/evening. Seas around

2 feet this morning build to 3 to 4 feet late afternoon and 

into tonight.



Outlook... 



Winds and seas will be below SCA levels for Friday and into the

weekend. The biggest hazard will be scattered tstms for the 

periods. The mostly likely times will be afternoons into the 

early evening period.



&&



.TIDES/COASTAL FLOODING...

The recent New Moon and increasing onshore flow will lead to higher

confidence in advisory level tidal flooding occurring this evening.

While we get away from the New Moon, onshore flow will result in

water piling up and more widespread minor tidal flooding for the

coastal and Delaware Bay communities. It appears that the higher

water levels will only be for one tide cycle, but we'll monitor

later today to assure that this trend continues. 



No tidal flooding is expected within the tidal Delaware River or 

Chesapeake Bay.



&&



.PHI WATCHES/WARNINGS/ADVISORIES...

PA...None.

NJ...Coastal Flood Advisory from 7 PM this evening to 1 AM EDT 

     Friday for NJZ012>014-020-022>027.

DE...Heat Advisory until 8 PM EDT this evening for DEZ001>003.

     Coastal Flood Advisory from 7 PM this evening to 1 AM EDT 

     Friday for DEZ003-004.

MD...Heat Advisory until 8 PM EDT this evening for MDZ012-015-019-

     020.

MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ450.



&&



$$



SYNOPSIS...OHara

NEAR TERM...MJL/RCM

SHORT TERM...OHara

LONG TERM...OHara

AVIATION...MJL/OHara/RCM

MARINE...MJL/OHara/RCM

TIDES/COASTAL FLOODING...PHI

