textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Special Weather Statement issued for patchy dense fog this morning for areas north and west of the I-95 corridor.

Increasing chance for excessive rainfall Sunday and Sunday night.

KEY MESSAGES

1. Patchy fog this morning gives way to clearing skies.

2. A series of cold fronts and low pressure systems will bring unsettled weather to the area starting Saturday night and continuing through at least Tuesday. Heavy rain from time to time is possible.

DISCUSSION

KEY MESSAGE 1... Patchy fog this morning will temporarily reduce visibilities before clearing out after daybreak. High pressure builds in from the north in the wake of cold front that moved through last night. Temperatures remain warm Friday afternoon with highs in the upper 70s to mid 80s, but dew points will fall slightly, making it feel more comfortable. Cooler temperatures arrive during the day Saturday with highs only warming up into the 70s. Conditions should start out mostly sunny Saturday morning, then mid and high clouds will build into the region throughout the day.

KEY MESSAGE 2... A series of cold fronts and low pressure systems will bring unsettled weather to the area starting Saturday night and continuing through at least Tuesday. Heavy rain from time to time is possible.

High pressure moves out to sea Saturday night, and then low pressure organizes and develops over the Midwest. A warm front extending out from that low will lift north through the Northeast Saturday night through Sunday morning. Showers first develop after midnight Saturday night and continue through Sunday morning.

As low pressure draws nearer to the region, southerly flow increases throughout the Northeast and low level moisture increases as well with surface dew points rising well into the 60s and low 70s and PWATs will be in excess of 2 inches. Low pressure then passes through the southern Poconos and Lehigh Valley Sunday afternoon and evening, resulting in more widespread showers with isolated thunderstorms across most of the area during that time. Locally heavy rain may develop from time to time. A cold front passes through the region behind the departing low, and that front will sag south towards Delmarva by Monday morning, where it will stall out.

WPC now has a Slight Risk for Excessive Rainfall (2 out of 4) for Sunday and Sunday night for areas along the I-95 corridor and points north and west. A Marginal Risk remains for the rest of the region south and east of the I-95 corridor. A Marginal Risk also continues for the entire region into Monday.

Several more disturbances will pass through the region Monday and Tuesday, and this will keep rain chances in the forecast during this time. For now, PoPs are limited to 30 to 50 percent (chance) given the uncertainty of the timing and coverage of showers.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

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

Friday... VFR expected. Decreasing clouds early then mostly sunny expected. North winds increasing to around 10 kts with gusts to 15 kts. High confidence.

Friday night... Prevailing VFR. NNE winds around 10 kts. High confidence.

Outlook...

Saturday...VFR. No significant weather.

Saturday night through Monday...Sub-VFR from time to time in SHRA, isolated TSRA (mainly Sunday afternoon and Sunday night), low stratus, and fog.

Tuesday...Sub-VFR conditions possible with showers around with breezy northeast winds.

MARINE

No significant marine headlines through Friday night. Seas linger around 2 to 3 feet. NW winds around 10 kts turn NE in the evening before gradually surging to around 15-20 kts overnight.

Outlook...

Saturday through Sunday...Sub-SCA conditions. Showers and storms Sunday and Sunday night.

Monday through Tuesday...SCA headlines may be needed on Monday for east to northeast winds 15 to 20 kt with gusts up to 25 kt and 4 to 6 ft. Gales possible Tuesday with wind gusts exceeding 30 kts.

VSBY restrictions in showers and isolated thunderstorms Sunday through Monday.

Rip Currents...

Friday...North winds 10 to 15 mph with breaking waves of 1 to 2 feet with a light southerly swell with a 4 to 6 second period. As a result, there is a LOW risk for the development of dangerous and life threatening rip currents for the Jersey Shore and Delaware Beaches.

Saturday...East winds 10 to 15 mph with gusts up to 20 mph. Easterly swells with a 10 to 12 second period. As a result, there is a MODERATE risk for the development of dangerous and life threatening rip currents for Monmouth county and Ocean county shores and a LOW risk for Atlantic county and coastal Cape May county shores and Delaware Beaches.

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

PHI WATCHES/WARNINGS/ADVISORIES

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