textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated aviation discussion.

KEY MESSAGES

1. A low pressure system will pass through the region this weekend with widespread showers and below normal temperatures.

2. Additional chances for much-needed rain arrive during the middle of next week.

DISCUSSION

KEY MESSAGE 1...A low pressure system will pass through the region this weekend with widespread showers and below normal temperatures.

A high pressure system to the north in eastern Canada will extend down into the Northeast this weekend. As a result, winds will be out of the east-northeast through Sunday. This onshore flow will help keep temperatures on the chillier side through the weekend. Highs in the upper 40s to mid 50s are expected through Sunday.

A low pressure system will continue to push the region overnight before moving offshore Sunday. This low pressure system will continue to bring rain to the area through tonight. The most widespread coverage of the rain looks to be through this evening into the early overnight hours. Rain will taper off to showers or drizzle by dawn Sunday morning, with perhaps a lingering shower into Sunday afternoon near the coast. It'll be a wet, breezy, and chilly weekend, especially through Sunday morning. Rainfall totals through Sunday, will range from around 0.50 to 1.50 inches across much of the area with localized higher amounts possible north. While this may be unpleasant, especially since it will be over the weekend, it is good to remember that this is a beneficial rainfall.

With cooler air wrapping in from the north tonight, it is possible some wet snow tries to mix in with the rain for the Poconos. Little to no accumulation is expected.

KEY MESSAGE 2...Additional chances for much-needed rain arrive during the middle of next week.

A brief period of high pressure on Monday, and some patchy frost may form in the Poconos overnight Monday night with radiational cooling and weak winds. A weak frontal boundary then approaches the region late Tuesday, bringing a chance for light rain. This frontal boundary will largely wash out across the region early Wednesday before another stronger low arrives late Wednesday into early Thursday that could bring more widespread showers and perhaps an isolated thunderstorm across the region.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

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

Tonight...MVFR ceilings will continue to lower to IFR through 03Z. Periods of light to moderate rain continuing through around 06-08Z, with MVFR visibility generally prevailing much of the time, briefly IFR visibility possible. Locally LIFR ceilings possible once the rain ends. Some areas of drizzle may occur after the rain ends as well. East winds shifting northeast overnight around 10-15 kts with gusts near 20-25 kts. Strong gusts at ACY. High confidence on prevailing IFR overnight, lower confidence on exact timing details.

Sunday...IFR ceilings early should slowly improve to MVFR during the afternoon, then to VFR by early evening. Lingering light rain or drizzle in the morning may result in MVFR visibilities. Northeast winds 10-15 kts with gusts up to 20 kts early, diminishing to 10 kts or less late. Moderate confidence on the timing of improvements in the TAFs.

Outlook...

Sunday night and Monday...VFR.

Tuesday...VFR ceilings overall. Some afternoon/evening showers possible.

Wednesday...Sub-VFR conditions along with showers likely.

Thursday...VFR overall.

MARINE

A Small Craft Advisory is in effect for all coastal waters out to 20 NM as well as the Delaware Bay through 6 AM Sunday morning due to increasing winds and seas. After 6 AM Sunday, coastal waters from Manasquan Inlet NJ south to Fenwick Island DE, and out to 60 NM will have a Gale Warning in effect as winds increase during the daytime hours Sunday, ending at 8 PM Sunday evening. The SCA for the Delaware Bay will remain in effect through 8 PM as well. The SCA for coastal waters north of Manasquan Inlet out to 20 NM has been extended to 6 AM Monday as seas will remain elevated overnight even as winds decrease. Another, SCA will likely be needed for areas within the Gale Warning as seas remain elevated in that area as well.

In addition to SCA and Gale conditions, visibility restrictions are also expected for all marine areas in rain and fog this evening, overnight, and into Sunday.

Outlook...

Monday through Monday night...SCA conditions will linger through Monday with NE winds gusting near 25 kts and seas at 5-7 feet. Winds diminish below SCA criteria Monday night, but seas will remain elevated.

Tuesday through Thursday...SCA conditions possible due to elevated seas around 5 feet.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 8 PM EDT Sunday for ANZ430-431. Small Craft Advisory until 6 AM EDT Monday for ANZ450. Small Craft Advisory until 6 AM EDT Sunday for ANZ451>455. Gale Warning from 6 AM to 8 PM EDT Sunday for ANZ451>455- 481>483-485.