textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated aviation discussion for 0z TAFs.

KEY MESSAGES

1. Low pressure continues to withdraw and improving conditions expected overnight.

2. Below normal temperatures continue this weekend into early next week.

3. Widespread minor coastal flooding is expected to continue tonight for portions of Ocean County New Jersey and Sussex County Delaware. Flooding will be confined mainly to back bay areas.

DISCUSSION

KEY MESSAGE 1...Low pressure continues to withdraw and improving conditions expected overnight.

A vigorous upper-level trough continues to swing across the Northeast U.S. tonight and into Saturday. The main surface low is now well offshore and will continue to move away across the North Atlantic overnight. The widespread precipitation across the region has been ending from SW to NE today and this trend will continue into the evening. While the best dynamics will move away, there will still be opportunities for extra cloudiness and scattered showers across the far NW areas. These will develop as a result of upstream lake-effect activity across North PA and upstate NY.

It'll remain cold tonight with lows dropping below normal. Lows will reach the upper 20s to low 30s in most areas. Winds will decrease from 10 to 15 mph to 5 mph or so later tonight.

Key Message 2...Below normal temperatures continue this weekend into early next week.

As low pressure moves into the Canadian Maritimes this weekend and high pressure builds to our west, northwesterly flow will continue to usher in cold air into the region. This will keep temperatures slightly below normal through the weekend into early next week. In fact, a Freeze Warning is in effect tonight through Saturday morning for all counties whose growing season has not ended with the exception of Philadelphia County which has a Frost Advisory. If the cold does not end the growing season for any of these areas, another Freeze Warning/Frost Advisory is possible the next couple of days as well.

In addition to the colder temperatures, winds will be gusty during the day due to a tight pressure gradient across the area through the weekend with winds gusts of 20-30 mph possible.

With the cold air and northwest flow, there will also be the possibility for some lake effect/lake enhanced snow or rain showers in the Poconos and higher elevations of Sussex County, New Jersey as well.

KEY MESSAGE 3...Widespread minor coastal flooding is expected to continue tonight for portions of Ocean County New Jersey and Sussex County Delaware. Flooding will be confined mainly to back bay areas.

Water levels have diminished for most areas following this morning's high tide. However levels remain elevated in back bay areas of Ocean County New Jersey and Sussex County Delaware where a Coastal Flood Advisory is in effect until 4 AM Saturday. This includes Rehoboth Bay and Little Assawoman Bay in Delaware and Barnegat Bay in New Jersey. Some places may stay above minor flooding thresholds through this afternoon's low tide before waters levels come up again with the high tide later this evening. Expect levels to remain below moderate thresholds so the Coastal Flood Warning for Ocean County was converted to an Advisory. For the day Saturday and beyond, no further flooding is expected as NW winds should help flush out water trapped in the back bays.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

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

Tonight...MVFR cigs will continue improve with time from NW to SE. It's already VFR at RDG and ABE and expect the I-95 TAF sites to be VFR by later this evening. Improvement may take a bit longer though at MIV and ACY. ACY has actually see cigs drop to IFR but this should improve to at least MVFR by later in the evening. Moderate confidence.

Saturday...VFR. Scattered to broken clouds around 4-5 thousand feet. NW winds gusting 20 to 25 knots. High confidence.

Outlook...

Saturday...Mainly VFR. Northwest wind gusts 20-25 knots expected.

Sunday thru Tuesday...VFR expected.

MARINE

Low pressure offshore continues to move away, despite the strong dynamics and colder airmass flowing across the mild waters, gusts have largely remain below Gale criteria. A few Gale gusts could occur into the evening, but overall, a SCA flag will better serve the situation into Saturday. Showers end this afternoon and evening then fair overnight. Fair weather Saturday. Rough seas into tonight.

Outlook...

Saturday night...Small Craft Advisory conditions diminish early. Fair weather.

Sunday thru Tuesday...sub-SCA conditions predominate. Fair weather.

PHI WATCHES/WARNINGS/ADVISORIES

PA...Freeze Warning from midnight tonight to 9 AM EST Saturday for PAZ070-102-104-106. Frost Advisory from midnight tonight to 9 AM EST Saturday for PAZ071. NJ...Freeze Warning from midnight tonight to 9 AM EST Saturday for NJZ016>018-021-023. Coastal Flood Advisory until 4 AM EST Saturday for NJZ020-026. DE...Freeze Warning from midnight tonight to 9 AM EST Saturday for DEZ001>003. Coastal Flood Advisory until 4 AM EST Saturday for DEZ003-004. MD...Freeze Warning from midnight tonight to 9 AM EST Saturday for MDZ012-015-019-020. MARINE...Small Craft Advisory until 6 PM EST Saturday for ANZ430-431- 450>455.