Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 311001 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 601 AM EDT TUE MAY 31 2016 .SYNOPSIS... A frontal boundary will stall over the area today before dissipating late tonight into Wednesday morning. High pressure builds in from eastern Canada Wednesday and Thursday. A cold front will approach from the west Thursday night and move through the Mid-Atlantic region on Friday. High pressure briefly builds in Saturday. An area of low pressure is forecast to move across the Great Lakes region late in the weekend and then pass to our north early next week. A cold front associated with this low pressure system will move through during this time. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... At 330 am, the cold front was located across northwestern New Jersey, extending to the southwest through the Lehigh Valley. The front doesn`t make much progress today and looks like it just dissipates over our area later today. Weak high pressure will start to push down from the north today. As the high pushes in, the skies will start to clear from west to east and we should have plenty of sunshine across the region. It may take a little bit longer for the skies to clear across eastern areas but still anticipate that the sun will make an appearance today. The front is dry and we do not anticipate any precipitation associated with this feature. However, the moisture from Bonnie`s remnants may still push up into our southern areas. Confidence is not high that much will materialize but have kept some slight chance pops over the southern part of Delaware and Maryland`s eastern shore for this afternoon and early evening. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... The high to our north will continue to influence our weather through tonight. The remnant moisture will exit the region for good and all areas should remain dry overnight. Enough low level moisture across the region may result in some patchy fog forming, especially across the southern zones. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Wednesday and Thursday...High pressure builds down from Hudson Bay Wednesday morning. The high will then shift eastward toward the Canadian Maritime with it`s ridge axis extending southwestward along the New England coast and Mid-Atlantic states Wednesday afternoon through Thursday. With moisture returning back northward around the periphery of the high, there is a potential for showers to develop across eastern PA/MD during peak heating both Wednesday and Thursday. Kept coverage of showers isolated and confined to our far western forecast zones since models are showing a lack of organized /larger-scale lift over us while the low-level theta-e ridge and axis of convective instability develops farther inland. Temps will be cool in the coastal plain and at the beaches on Wednesday thanks to the onshore flow that develops under this setup. There is an opportunity for highs to reach the lower 80s from the Delaware Valley, westward with a fair amount of sunshine to start the day. Slightly cooler temps (at or just below climo) anticipated for Thursday as the onshore flow persists for a second day, allowing for the marine layer and accompanied stratocu deck to become better established across the entire area, even inland locations. Friday...High pressure along East Coast retreats offshore late in the week as a cold front approaches from the west. The front looks to make slow progress through our region Friday, perhaps not moving offshore until Friday night. Meanwhile, the remnants of Tropical Storm Bonnie that was stalled near the Southeast Coast is forecast to finally lift northeastward and out to sea. Some of its tropical moisture could be drawn poleward up the Eastern Seaboard within the pre- frontal warm sector ahead the cold front. This could enhance coverage of showers and storms as well as rainfall amounts. The risk of locally heavy rainfall will depend on the interaction between these systems and other environmental factors on the mesoscale. Opted to keep any mention of a flooding threat out of HWO for now given the limited support in the QPF fields from forecast guidance and the limited predictability inherent with determining the finer details on the mesoscale several days out. Saturday through Monday...The first half of the weekend looks to be dry assuming the cold front has already moved offshore and high pressure builds in from Canada. Precip chances increase later in the weekend into early next week as an area of low pressure is forecast to move into the Great Lakes on Sunday and the Northeast on Monday. There is a chance for showers and thunderstorms during this time along and ahead of the attendant cold front that is forecast to move through our area. Near-normal temps will prevail during the extended part of the forecast period. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. MVFR/IFR conditions this morning in fog and low clouds will clear between 12Z-14Z at the terminals, becoming VFR across the region. Light winds will gradually pick up but remain less than 10 knots through the day. With light winds expected, a sea breeze will likely develop along the coast and will make it inland to KACY and possibly reach KMIV. A few showers may develop this afternoon but are expected to remain to the south of the terminals. Fog may form again tonight, especially south and east of KPHL. OUTLOOK... Wednesday and Thursday...Light east to southeast winds. Marine stratocu deck may result in MVFR cigs along the coast Wednesday afternoon/night that expands inland by Thursday. IFR cannot be ruled out along the coast overnight Wednesday and then overnight Thursday across any of the terminals. Low confidence in timing/coverage of these CIG restrictions. Friday...MVFR with low clouds and fog at the start of the day improves to mainly VFR by midday. Chance of showers and storms. Temporary flight restrictions possible in heavier activity. Otherwise, VFR. Saturday...Mainly VFR. && .MARINE...
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The dense fog advisory has been extended until 4 pm for the ocean waters and lower Delaware Bay. The cold front is getting hung up to the west of the area waters this morning and with warmer air continuing to move over the waters, fog will continue to develop. Other than fog being an issue on the waters, conditions look to be fairly benign. Seas will remain around 2 to 4 feet through today. Winds will remain light through the day, but may pick up this afternoon out of the east. OUTLOOK... Wednesday through Saturday...Winds and seas below SCA criteria through much of the outlook period. Winds will be under 20 kt and generally onshore through Friday. They may briefly become more northerly behind a front Friday night or Saturday. Seas in our coastal Atlantic zones will mainly be between 2 and 4 ft throughout the period.
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&& .TIDES/COASTAL FLOODING... Onshore flow is expected to develop on Wednesday and continue into Friday. We will need to monitor the possibility of minor tidal flooding at times of high tide along the coast late this week owing to the persistent onshore flow and the approaching new moon this Saturday. && .PHI WATCHES/WARNINGS/ADVISORIES...
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PA...None. NJ...None. DE...None. MD...None. MARINE...Dense Fog Advisory until 4 PM EDT this afternoon for ANZ431- 450>455.
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&& $$ Synopsis...Klein Near Term...Meola Short Term...Meola Long Term...Drag/Klein Aviation...Klein/Meola Marine...Klein/Meola Tides/Coastal Flooding... is the U.S. government's official web portal to all federal, state and local government web resources and services.