textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated aviation discussion.

KEY MESSAGES

1. Today will be cooler with less wind and higher humidity levels compared to yesterday.

2. Low pressure will pass through the region this weekend with widespread showers and seasonably chilly temperatures.

DISCUSSION

KEY MESSAGE 1...Today will be cooler with less wind and higher humidity levels compared to yesterday.

The high to our north along with low pressure east of the Canadian Maritimes will help drive a backdoor cold front southward through the area this morning. This will also bring some increasing cloud cover. Expect partly to mostly cloudy skies with light NE winds and cooler temperatures compared to yesterday. Highs will be mainly in the 60s to around 70 except cooler near the coast and a bit warmer over our eastern MD counties in Delmarva since this will be closer to the front. The cooler temperatures will result in humidity levels being higher than today along with lighter winds so we don't expect there to be fire weather concerns.

KEY MESSAGE 2...Low pressure will pass through the region this weekend with widespread showers and seasonably chilly temperatures.

High pressure will be settled over eastern Canada, and the base of this high will extend down into the Northeast. As a result, winds will take on an easterly flow starting Friday night, and onshore flow will persist through most of the weekend. This will usher a chilly airmass into the region due to ocean temperatures 50s. High temperatures Saturday and Sunday will be in the 50s with lows in the 40s.

Low pressure will organize and develop over the Great Lakes Friday night and will dive towards the Delmarva Peninsula and the Mid- Atlantic on Saturday before departing throughout the day Sunday. Showers develop Saturday night, and then continues throughout the day Saturday and Saturday night. Will keep chance PoPs for Sunday morning as that low departs.

This all sets up a raw, breezy, wet weekend.

Rainfall totals this weekend, at least from Friday night through Saturday night, will range from 1 to 1.25 inches across the southern Poconos, northern New Jersey, and the Lehigh Valley, and from 1/2 to 1 inch across the Delaware Valley, including Philadelphia, southern New Jersey, and Delmarva. While this may be unpleasant, especially since it will be over the weekend, it is good to remember that this is a beneficial rainfall.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

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

Thru 12Z this morning...VFR with mainly high clouds. Northeast winds generally 5 kt or less. Calm periods are possible. High confidence.

Today...VFR with BKN mid-level clouds at times. Winds northeast shifting to southeast 5-10 kt. Moderate confidence.

Tonight...Mostly VFR, but with lowering cigs, possibly becoming MVFR by dawn. Showers possible in the evening will be more likely toward dawn. Winds southeast, shifting east, 5-10 kts. Moderate confidence.

Outlook...

Saturday through Saturday night...Sub-VFR conds in SHRA, patchy fog, and low stratus.

Sunday...Lingering sub-VFR conds in SHRA/stratus in the morning. Gradual improvement late.

Sunday night through Monday night...VFR. NSW.

Tuesday...Sub-VFR conds in SHRA/stratus.

MARINE

Sub-Small Craft Advisory conditions through tonight. Winds will generally be around 10 knots or less with seas generally 2 to 4 feet through tonight.

Outlook...

Saturday through Sunday night...SCA conditions will develop on Saturday with 15 to 20 kt winds with 25 to 30 kt gusts and seas 6 to 8 ft. Cannot rule out a few brief gale force gusts, mainly on the New Jersey ocean waters, Sunday afternoon. VSBY restrictions in rain and fog.

Monday through Monday night...SCA conditions, mostly for 5 to 6 ft seas on Monday, Conditions subside to sub-SCA conditions Monday night.

Tuesday...Sub-SCA conditions likely.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...None.