Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 250118 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 918 PM EDT Sat Jun 24 2017 .SYNOPSIS... High pressure will attempt to build into the mid- Atlantic region overnight and Sunday. However some trofiness will persist over the Great Lakes and New England through Tuesday. Stronger high pressure is forecast to build in for Wednesday and then move offshore Thursday and Friday. A frontal system approaching from the northwest may bring a chance for showers Friday and Saturday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... A shortwave surface ridge is expected to build close to the region overnight. That combined with the continued dry air advection in the wake of the cold front this morning means dry conditions and clearing skies through the overnight hours. Thanks to the drier conditions and clearing skies, temperatures are expected to drop off a bit more than what we have seen the last few nights. Low temperatures are expected to range from the upper 50s to near 70. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... The surface ridge will weaken quickly as a mid and upper level shortwave trough digs southeast towards New England. The lift associated with this feature may be enough for convective initiation across the Poconos and NW NJ, but we aren`t expecting any widespread precipitation as we will remain quite dry through the day tomorrow. Temperatures tomorrow are expected to be near or just below temperatures today as the northwesterly flow regime redevelops. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... Monday and Monday night...Another cold front is expected to move through the region through this period. In the mid and upper levels, a positively tilted short wave trough will be trailing close behind. Despite ample lift and upper level support, do not expect too much in the way of precipitation across the region primarily because we are not expecting any significant moisture advection before this period. An upper level trough remains over the eastern US on Tuesday with some associated surface trofiness as well. Guidance supports just a slight chance for showers or an isolated t-storm. Then stronger surface high pressure builds in over the mid-Atlantic region on Wednesday as the upper trof moves offshore. At this time Wednesday looks to be dry with slightly below normal temperatures continuing from Tuesday. On Thursday and Friday the high pressure moves offshore and low pressure moves across the Great Lakes. This sets up a southwest flow around the sub-tropical ridge with increasing heat and humidity towards the end of the week. A frontal system is forecast to approach from the northwest but is not expected to reach the area. However the increasing low-level moisture and typical surface trof in the lee of the mountains will make conditions favorable for afternoon showers and t-storms, especially north/west of PHL. High temperatures a few degrees above normal are expected Thursday through Saturday. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. VFR conditions are expected through the TAF period. Some mid level clouds near or above 5000 ft AGL may move over the region after 03Z. Winds are expected to subside to near or below 10kt by 00Z. Wind direction may back to westerly overnight. Around 18Z tomorrow, expect wind speeds to once again increase with 10g20kt possible for much of the afternoon at all TAF sites. OUTLOOK... Sunday night through Monday night...Mostly VFR conditions are expected. There is a small chance for showers and thunderstorms Monday and Monday night. If any move over the TAF sites, MVFR or lower conditions will be possible. Monday and Tuesday...Mostly VFR but a chance for tempo lower conditions in isolated thunderstorms, mainly for ABE and RDG. West wind mainly 10 kt or less. Wednesday and Thursday...VFR condions expected. Light west winds on Wednesday become southwest on Thursday with gusts to 20 kt possible in the afternoon. && .MARINE... Winds and seas have subsided below SCA criteria across the Delaware Bay and the coastal waters south of Little Egg Inlet. However...seas remain just over the 5 foot critera north of Little Egg so a SCA continues in those locations through most of the overnight hours. Below SCA conditions are expected everywhere on Sunday. OUTLOOK... Sunday night through Monday night...Winds and seas should stay below SCA criteria. Tuesday and Wednesday...Winds and seas are forecast to remain below SCA conditions. Thursday...SCA conditions may develop in the afternoon. && .TIDES/COASTAL FLOODING... Water levels at the time of high tide this evening are expected to approach but not quite exceed minor threshold levels...especially considering the offshore no coastal flood advisories have been issued. A similar situation may develop again with Sunday evening`s high tide. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 5 AM EDT Sunday for ANZ450-451. && $$ Synopsis...AMC Near Term...Johnson/Miketta Short Term...Johnson Long Term...AMC/Johnson Aviation...AMC/Johnson/Miketta Marine...AMC/Johnson/Miketta Tides/Coastal Flooding...Miketta is the U.S. government's official web portal to all federal, state and local government web resources and services.