478 FXUS61 KPHI 091744 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 145 PM EDT Fri Jul 9 2021 .SYNOPSIS... Tropical Storm Elsa will track towards eastern Long Island this morning A cold front approaching from the northwest is expected to arrive tonight. This front is anticipated to stall nearby over the weekend before lifting to the north early next week. && .NEAR TERM /THROUGH TONIGHT/... Tropical Storm Elsa continues to move away from the area and into New England. We now have northwest flow wrapping cyclonically around the back of the storm, and wind speeds have decreased significantly even at the coast. Surface observations and satellite imagery reveal a pleasant day developing across the area in the wake of Elsa, with most areas seeing sunshine and temperatures rising into the 80s. The northwest flow has brought in somewhat drier air, but dew points remain in the upper 60s and lower 70s, and with the wind shifting back to southwest this afternoon, it will remain on the humid side. A shortwave trough will track into upstate New York by this evening. A well-defined surface cold front sits over west-central Pennsylvania as of late this morning and will approach our region by late this afternoon. Moderate instability (SB CAPE up to 2000J/kg) is expected to build ahead of the front. We'll also see up to around 30 kt of bulk shear, not great but definitely enough to allow some multi-cellular or linear segments to organize. It's tough to gauge convective potential so soon in the wake of a tropical cyclone. There tends to be considerable synoptic scale subsidence in the wake of such storms. The atmosphere was certainly very worked over at least in the eastern half of the area by heavy rain last night, so it remains to be seen how well it will recover. But the sounding profiles this afternoon do look favorable for damaging wind with good DCAPE developing and some mid-level dry air working in, which tends to enhance wind damage potential if it is not strong enough to cut off the updrafts. Could see some small hail also. So overall, think the greatest threat for severe weather will be east/southeast PA and Delmarva where forcing and instability are best, but some risk will exist all across the area. Timing-wise, storms should approach and/or develop over the western zones heading towards 2-4PM, and should they hold together would get to the coast towards sunset. The front will move through during the later evening hours, giving way to a dry overnight. Winds will shift back to northwest behind the front, and lows will fall into the 60s. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... The rain-free weather will be short lived as higher moisture and warm advection returns Saturday night continuing into Sunday and Sunday night. Scattered showers will move into western sections late Saturday night and continue Sunday and Sunday night with afternoon/evening thunderstorms. && .LONG TERM /MONDAY THROUGH FRIDAY/... A strong surface high over the western Atlantic Ocean will occasionally strengthen and ridge back across the Middle Atlantic states. Meanwhile, a trough/low across the Plains and Ohio Valley region will remain in place through early mid week and then eject out across the Great Lakes area. Precipitation will mostly be convective in nature with late afternoon and evening hours favored. The heat will return with afternoon temperatures in the lower 90s, but 80s in the mountains and along the coast. && .AVIATION /16Z FRIDAY THROUGH WEDNESDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Today... Improving conditions through the morning with VFR returning to the NW taf sites first and the coastal areas towards late morning. Winds will be somewhat variable thru 12Z with the tropical storm moving thru the coastal areas then become NW or W by late morning. The previous TAFS had TS for later today, but my confid in this is not very great, so they were removed for now. Tonight... VFR expected with light W winds. Patchy fog possible. Outlook... Friday night/Saturday...Mostly VFR. Patchy fog around dawn Sat. Sat night thru Wednesday...Mostly VFR, but scattered showers and tstms with lower CIGS/VSBYS possible. && .MARINE... All Tropical Storm Warnings have been cancelled. SCA is up for the ocean waters for the rest of today, but has already expired for the Delaware Bay thanks to diminishing winds. Seas remain elevated after winds diminish to below 25-30 kt. Scattered showers and thunderstorms possible for the late afternoon and early evening. Winds and seas higher in tstms. Outlook... Saturday through Wednesday...Mostly sub-SCA conditions expected. Scattered showers and tstms Sunday through Wednesday will bring localized higher winds and seas. Rip currents... A HIGH risk for rip currents is expected today. A MODERATE risk for rip currents is expected for Saturday. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...High Rip Current Risk until 9 PM EDT this evening for NJZ014- 024>026. DE...High Rip Current Risk until 9 PM EDT this evening for DEZ004. MD...None. MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ450>455. && $$ Synopsis...Haines Near Term...O'Brien Short Term...Franklin Long Term...Franklin Aviation...Franklin/O'Brien Marine...Haines/Iovino/MPS/O'Hara/Franklin