NEAR TERM /THROUGH THURSDAY/
High pressure centered near Nantucket is in control and will remain parked off to the northeast through tomorrow, fostering a light onshore flow, and bringing tranquil conditions. A Rex Block will begin to set up as well over the Eastern US, prolonging a period of quiet weather.

For tonight, expecting pretty favorable conditions for radiational cooling yet again with light winds and mostly clear skies. Some patchy radiational fog is expected to develop, mainly in valleys + rural and secluded areas. Areas of fog could locally be dense, but not widespread enough to issue any advisories. Temperatures will fall into the low to mid 50s, with upper 50s along the coast and within the urban corridor.

Any fog mixes out quickly by mid-morning and we are looking at another very nice mid-September day. Temperatures will climb into the upper 70s/low 80s. Another sea-breeze looks to develop, but that is about the only mentionable thing about tomorrow as it looks quiet.

SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/
High pressure will be situated to our north and northeast near or off the coast of New England through much of the short term period leading to continuing onshore flow. Aloft, a Rex Block pattern will be setting up as upper level ridging builds over the Great Lakes and a closed low associated with what is currently Hurricane Francine meanders over the south-central US.

All in all, this will result in dry weather with mainly clear to partly cloudy skies throughout the period with some occasional high clouds from Francine fanning in from south to north at times. There may also be a period of some low stratus that develops late Thursday night into early Friday over southern parts of the forecast area (Delmarva, south Jersey, SE PA). Highs will generally be in the upper 70s to mid 80s, with lows ranging from the mid 50s to low 60s.
Humidity should remain rather comfortable.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
As a whole, the long term period remains relatively unchanged through the weekend as the Rex Block pattern continues. This will yield continuing dry conditions along with above normal temperatures through Sunday.

The blocking pattern does appear that it will break down early next week, which may finally result in some much needed precipitation returning to the area by midweek. For now, both the GFS/ECMWF global guidance indicate that there is potential for the development of a tropical disturbance off the Southeast US eventually lifting northward by midweek. Will have to monitor this closely as weather features following blocking patterns are often difficult to predict, but considering model to model run consistency, have maintained a 20- 30% chance of showers on Tuesday and Wednesday for much of the area.

AVIATION /02Z THURSDAY THROUGH MONDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Tonight...VFR to start. Patchy fog develops after midnight, though the more urban terminals (KPNE, KPHL, KILG) should stay VFR. For the remaining terminals, MVFR VSBYs should be developing around 07z-08z with periods of IFR expected at times.
The exception being KTTN, where some LIFR visibility is possible late tonight. Moderate confidence in timing of restrictions developing. Low to moderate confidence in extent of restrictions.

Thursday...Conditions lift to VFR quickly by the mid-morning.
Southeast winds around 5-10 kt. Moderate confidence.

Outlook...

Thursday night through Monday...Mainly VFR except will have to watch for low stratus potential Thursday night into Friday which has a chance (20-30 percent) of bringing some MVFR cigs into our southern sites (PHL southward) Thursday night into early Friday.

MARINE
No marine headlines expected through Thursday. Winds generally out of the east around 5-10 kt with 2 foot seas.

Outlook...

No marine headlines are expected Thursday night through Saturday night. However by late Sunday into early next week seas look to increase to levels near or above Small Craft Advisory levels due developing system south of our waters.

Rip currents...

Through Friday...Northeast winds around 10 mph will become east to locally southeast each afternoon and evening. Breaking waves in the surf zone are forecast to be around 2 feet with a period of around 8 seconds. As a result, there is a LOW risk for the development of dangerous rip currents for both the Jersey Shore and the 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.