textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Freeze Warning has expired. Updated Key Message 1.

KEY MESSAGES

1. A cold airmass continues this weekend. Another round of frost is possible tonight into Monday morning.

2. Uncertainty persists regarding a nor'easter developing off the coast of the southern Mid-Atlantic that may cause unsettled conditions and hazardous marine impacts early next week.

DISCUSSION

KEY MESSAGE 1. A cold airmass continues this weekend. Another round of frost is possible tonight into Monday morning.

The Freeze Warning expired at 9 AM. Temperatures early this morning dropped to or below freezing across portions of eastern Pennsylvania and northern New Jersey. Given the widespread freezing temperatures observed, the 2026 growing season has ended for the following counties...

In Pennsylvania...Carbon, Monroe and Northampton counties.

In New Jersey...Sussex and Warren counties.

No additional frost/freeze headlines will be issued for these counties until Spring 2027.

Sunny and chilly today with highs about 10 degrees below average, topping off mostly in the upper 50s.

Another cold night on tap for tonight, and additional frost and/or freeze headlines may be needed for areas where the growing season continues.

Temperatures will then begin to slowly moderate into early this week.

KEY MESSAGE 2...Uncertainty persists regarding a Nor'easter developing off the coast of the southern Mid-Atlantic that may cause unsettled conditions and hazardous marine impacts early next week.

The base of a deep trough axis will pass through the region late tonight into Sunday. As it does so, the trough axis will then cutoff into an upper level low which will meander over the southern Mid-Atlantic coast into early next week. At the same time, strong and expansive high pressure will be building over the Ohio Valley. While confidence is increasing regarding a nor'easter developing off the North Carolina coast by Sunday into Sunday night, it must be said there remains a vast amount of uncertainty with regards to potential impacts to our region into next week.

Considerable differences amongst global/ensemble guidance exists with regards to just how close/long this system will get/last in our region. Relative to the previous forecast discussion, there has not been much change. The EC ensemble member spread is fairly tightly clustered through the early part of next week, and then begins to diverge, but generally has the low tracking northward and then meandering off the Mid-Atlantic coast into mid or even late week. The GEFS members are similar until about mid-week when they begin to diverge more substantially. All of this being said, it doesn't appear likely that there will be significant impacts inland from this system, even though they can't be entirely ruled out at this time. What is increasingly likely though is at least some impacts to coastal communities with periods of gusty northeast winds, some showers, and potentially some coastal flooding concerns, potentially for multiple days next week. We will continue to monitor the progress of this developing system.

AVIATION /13Z SUNDAY THROUGH THURSDAY/

The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Today...VFR. N winds 8 to 12 kt, becoming NE. High confidence.

Tonight...VFR. NE winds 5 kt or less. High confidence.

Outlook...

Monday and Tuesday...VFR. Gusty northeast winds up to 20 kt possible with gusts up to 30 kt also possible near KMIV and KACY.

Wednesday and Thursday...Primarily VFR, although sub-VFR conditions possible at times. A chance of rain showers each day, with chances highest for KMIV and KACY. Gusty northeast winds up to 20 kt possible with gusts up to 30 kt also possible near KMIV and KACY.

MARINE

Will go ahead and extend the Gale Warning for offshore waters until noon today. Otherwise, all other headlines remain in effect.

For Delaware Bay, Small Craft Advisories are in effect through noon today. For the coastal ocean waters of NJ and DE, Gale Warnings were converted to SCAs, which are in effect through tonight. N to NE winds 15 to 20 kt with gusts up to 25 kt will diminish this afternoon, but seas will remain elevated at 4 to 6 feet through tonight.

Outlook...

Monday through Thursday...Due to developing nor'easter off the southern Mid-Atlantic coast, a prolonged period of gale force conditions are expected to develop/continue across all marine waters. A Gale Watch remains in effect for Monday through Tuesday. Lower confidence for Wednesday and Thursday. Northeast winds of 25-35 kt with gusts of 35-45 kt are possible. Seas of 10-16+ feet possible.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until noon EDT today for ANZ430-431. Small Craft Advisory until 6 AM EDT Monday for ANZ450>455. Gale Watch from Monday morning through Tuesday afternoon for ANZ451>455-480>483-485. Gale Warning until noon EDT today for ANZ480>483-485.