textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated the aviation section for 06Z TAFs.

KEY MESSAGES

1. High pressure builds in through today, bringing cooler and less humid conditions.

2. Warmer and more humid conditions return Sunday, along with daily chances for showers and thunderstorms into the middle of the week.

DISCUSSION

KEY MESSAGE 1...High pressure builds in through today, bringing cooler and less humid conditions.

High pressure will build into the region today, with a cooler and much drier airmass in place. Highs will be mainly in the upper 70s to low 80s with some high clouds around. Overall, a very pleasant and dry day. Some patchy fog may develop tonight as winds go calm in many areas under mostly clear skies, though clouds will increase late. Lows mainly in the mid 50s to low 60s.

KEY MESSAGE 2...Warmer and more humid conditions return Sunday, along with daily chances for showers and thunderstorms into the middle of the week.

Broad upper level ridging returns to the eastern US early next week, bringing in surface high pressure across the eastern US. Afternoon highs will creep back into the mid 80s to low 90s, about 5 degrees above average for early September. Dewpoints will also creep back into the upper 60s to low 70s.

Convection potential will return starting Sunday, although any showers and storms should remain fairly isolated to widely scattered in nature and focused mainly along and NW of the I-95 corridor. Instability will be the limiting factor. Severe storms are unlikely, though gusty winds, small hail, and brief heavy downpours are possible with any stronger storms.

One other aspect to watch with this ridging pattern is the potential for thunderstorms to rotate around the periphery of the ridge and the position of a warm front next week. The exact location, timing, and intensity of the thunderstorms remains a bit uncertain at this range. Currently, the main days to monitor are Tuesday and Wednesday regarding heavy rain and severe weather potential.

AVIATION /07Z SATURDAY THROUGH WEDNESDAY/

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

Through 12Z...VFR. NNE winds 5-10 kts. High confidence.

Today...VFR. North to northeast winds around 5 kts, becoming light and variable after 18Z. Sea, bay, and river breezes should then favor south to southeast winds around 5 kts for PHL and south. High confidence.

Tonight...Prevailing VFR, though some patch fog is possible. Winds light and variable to calm. Low confidence on fog potential.

Outlook...

Sunday through Wednesday...Restrictions possible in showers and thunderstorms each day, mainly during the afternoon to evening hours.

MARINE

Northerly winds may briefly gust to around 25 kts through the predawn hours, but this should only be for a period of an hour or two at most. Otherwise, no marine hazards expected. Northeast winds 10-15 kts becoming lighter and shifting east to southeast late.

Outlook...

Saturday night and through Wednesday...No prevailing marine hazards expected. Chances for thunderstorms each day, mainly in the afternoon and evening hours.

Rip Currents...

For today, NNE winds of 10-15 mph decrease to around 5 to 10 mph while turning E to ENE in the afternoon. There is a 1 to 2 foot east-southeasterly swell with a period of 7-8 seconds. As a result, there is a MODERATE risk for the development of dangerous and life threatening rip currents at the Jersey Shore and Delaware Beaches.

On Sunday, S to SSW winds of 5-10 mph increase to 10-15 mph in the afternoon. A 1 foot southeasterly swell with a period of 7-8 seconds lingers. As a result, there is a LOW risk for the development of dangerous and life threatening rip currents at the Jersey Shore 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.