textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Cancelled/expired portions of the Small Craft Advisory and adjusted timing.

KEY MESSAGES

1. A cold front continues to approach this evening bringing some showers and perhaps a rumble of thunder, though no significant impacts are expected.

2. The overall weather pattern remains unsettled through the weekend with cool temperatures late week giving way to a warming trend over the weekend.

DISCUSSION

KEY MESSAGE 1...A cold front continues to approach this evening bringing some showers and perhaps a rumble of thunder, though no significant impacts are expected.

A cold front currently draped over central Pennsylvania continues to slowly inch its way toward our region. The initial round of light rainfall has come and gone.

As the front comes through this evening, there could be some isolated low topped thunderstorms right along the front, but this threat is waning at this hour. Storms will be mainly for South Jersey and Delmarva, but we cannot rule out a rumble of thunder for eastern PA early in the evening. No severe weather is expected from any storms. The front slowly sags south and east, with some showers possible overnight south/east of I-95, but nothing significant expected. With the slow progression of the front, latest hi-res guidance suggests a resurgence of showers overnight mainly across southeast NJ and the Delmarva come Thursday morning. Overall rainfall amounts from this evening forward will only add on a few hundredths across the I-95 corridor and points north and west to perhaps up to a 0.25 inch across the southeast NJ and southern Delmarva.

KEY MESSAGE 2...An unsettled pattern for Friday and the weekend.

An upper trough will remain across the Great Lakes and Northeast this weekend before heading off the coast early next week. The trough will allow several weak shortwaves to move across the Middle Atlantic and bring opportunities for showers or perhaps a thunderstorm (Sat afternoon). Pops are greatest for Saturday and then after a break (Sat night/Sun, morning) they climb again for Sunday (late afternoon and night and into Monday). These rains will bring additional relief for the overall dry conditions over our region.

Temperatures will generally be cooler than normal. One exception will be for Sunday when readings will climb into the mid/upper 70s for the N/W areas and upper 70s/low 80s elsewhere. The rest of the Fri-Tue. period will have highs in the mid/upper 60s with low 70s S/E. These temps are 2 to 4 degrees below normal.

AVIATION /00Z THURSDAY THROUGH MONDAY/

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

Tonight...Prevailing VFR expected at all terminals, although some spotty MVFR ceilings are possible at times. Isolated to scattered showers overnight, so have carried either VCSH/-SHRA at all terminals. There remains a slight chance of thunder overnight, however confidence in occurrence remains quite low, hence left out of all TAFs at this time. Winds will gradually shift from WSW to NW following frontal passage, but remain generally around 5-10 kt. Moderate confidence overall.

Thursday...VFR. SCT/BKN clouds expected, with periods of clear sky around mid-day. Northwest winds around 5-10 kt, gradually becoming westerly in the afternoon. High confidence.

Outlook...

Thursday night/Friday... VFR expected.

Friday night/Saturday... Showers with lower CIGs/VSBYs possible.

Saturday night/Sunday morning... VFR expected.

Sunday night/Monday... Widespread lower CIGs/VSBYs possible with frequent showers.

MARINE

Small Craft Advisories for the Delaware Bay and Atlantic Coastal Waters from Cape May to Fenwick Island have been cancelled/expired. A Small Craft Advisory remains in effect for the Atlantic Coastal Waters from Sandy Hook to Cape May until 2 AM Thursday.

Gusty winds up to 25 kt and seas around 3-6 feet are possible in SCA areas. Outside of SCA areas, marine conditions will remain below SCA criteria for the remainder of Thursday.

Outlook...

Overall, winds and seas look to remain below SCA levels for Friday and into the weekend. The synoptic systems look to be weak and show little impact on seas. A few solutions have shown a possibly stronger low offshore Sunday/Monday and this may create SCA conditions if it develops. Fair Friday. Showers Saturday and again Sunday night/Monday.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 2 AM EDT Thursday for ANZ450>453.