textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated Aviation section for 00Z TAFs.

KEY MESSAGES

1. A round of showers and thunderstorms overnight then improving conditions for Thursday.

2. Mostly quiet with seasonable temperatures in the extended though with some rain chances, mainly on Friday and late Sunday into Monday.

3. There is the potential for minor tidal flooding during the evening high tides this week along the Atlantic coast, Delaware Bay, and tidal Delaware River, especially with this evening's high tide.

DISCUSSION

KEY MESSAGE 1...A round of showers and thunderstorms overnight then improving conditions for Thursday.

Weak high pressure is across the area as of the early afternoon today, but this will weaken this evening. Shortwave energy across the Great Lakes aided by an upper jet stream will cause a disturbance to arrive from the northwest overnight. You can already see the beginnings of this presently as showers/tstms are developing across western NY. We have likely and categorical POPS for showers and tstms overnight. While severe weather is not expected, gusty winds and downpours will occur. The activity will diminish from NW to SE around dawn. Rainfall will generally be around one-quarter to one-half of an inch in many areas but a few spots may end up with totals closer to an inch. On Thursday, drier air will arrive and sunny skies are expected much of Thursday.

KEY MESSAGE 2...Mostly quiet with seasonable temperatures in the extended though with some rain chances, mainly on Friday and late Sunday into Monday.

An upper level ridge will anchor itself over the southeast US through the weekend. Our area will be on the northern periphery of the ridge, with a modest west/northwest flow. This will result in seasonable temperatures through the weekend and into next week with highs generally in the 80s.

A few shortwaves will impinge on the ridge, driving multiple rounds of low pressure through our area. This will result in a few chances for showers and thunderstorms, first on Friday, mainly for the southern half of the area. More widespread rain looks to come Sunday Night into Monday, which could also include a few thunderstorms. However, the risk for impactful and significant weather (severe/flash flooding) appears low at this time.

KEY MESSAGE 3...There is the potential for minor tidal flooding during the evening high tides this week along the Atlantic coast, Delaware Bay, and tidal Delaware River, especially with this evening's high tide.

The New Moon is today and as a result astronomical tides for this evening's high tide cycle will be near or over minor flooding thresholds for many places along the Atlantic coasts of New Jersey and Delware, Delaware Bay, and the tidal Delaware River. A Coastal Flood Advisory for this evening remains in effect for all areas along the Delaware Bay as well as along the Atlantic coast from Cape May County Southward. The highest astronomical tides will occur this evening but the threat of minor tidal flooding may linger through Thursday or Friday as well.

Tidal flooding is not currently forecast for the Eastern Shore of the Chesapeake Bay.

AVIATION /00Z THURSDAY THROUGH MONDAY/

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

Tonight...VFR initially. There is the potential for SHRA/TSRA through the night, but confidence is low on whether SHRA/TSRA will develop and if they will pass over a given terminal. MVFR or lower conds would be possible in convection. Kept PROB30 groups for convection potential. CIGs will otherwise lower to MVFR late. W-SW winds around 5 kt, becoming LGT/VRB late.

Thursday...Any MVFR CIGs will lift to VFR by 15Z, then VFR. W-NW winds increasing to around 10 kt with gusts up to 20 kt in the afternoon. Moderate confidence.

Outlook...

Thursday Night through Friday...Primarily VFR though restrictions possible (30-40%) with scattered showers/isolated thunderstorms moving through

Friday Night through Sunday Morning...VFR. No significant weather.

Sunday Afternoon through Monday...Sub-VFR conditions likely (60-70%) at times with widespread showers and a few embedded thunderstorms anticipated.

MARINE

No prevailing marine hazards expected tonight or Thursday. Showers and TSTMs are expected later tonight and into Thursday morning. Higher winds and seas in TSTMs.

Outlook...

Thursday Night through Sunday...No marine headlines expected.

Sunday Night through Monday...SCA conditions possible (30-40%) as seas near 5 feet and southerly wind gusts near 25 kt.

Rip Currents...

Rest of today...Southeasterly winds 10 to 15 mph by the late afternoon. Breaking wave heights will remain around 2 feet or less with a southerly 1 foot swell around 5 to 7 seconds. With little changes in overall conditions, will continue with a LOW risk for dangerous rip currents at all beaches.

For Thursday...A southwesterly wind around 5 to 10 mph. Breaking wave heights will remain around 2 feet or less with a southeasterly 1 foot swell around 6 to 8 seconds. Due to these conditions there is a LOW risk for dangerous rip currents at all beaches.

For Friday...the winds will shift to onshore but generally remain around 10 mph or less with breaking wave heights 2 feet or less. So we will continue with a LOW risk for dangerous rip currents at all beaches.

For specific beach forecasts, visit weather.gov/beach/phi

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...Coastal Flood Advisory until 2 AM EDT Thursday for NJZ016. Coastal Flood Advisory until 1 AM EDT Thursday for NJZ021-023- 024. DE...Coastal Flood Advisory until 2 AM EDT Thursday for DEZ001. Coastal Flood Advisory until 1 AM EDT Thursday for DEZ002>004. MD...None. MARINE...None.