Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 221912 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 312 PM EDT Wed Mar 22 2017 .SYNOPSIS... Large high pressure across the upper Great Lakes region this afternoon will slide southeast and crest over our region Thursday. A warm front will lift to our northwest Friday, while a backdoor cold front pushes through the area Saturday. This front is forecast to stall near the southern portions of the area or just to our south into early next week. A couple of low pressure systems may form along the boundary and move eastward as well. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Winds will drop off quickly through this evening as the surface high builds closer and the pressure gradient decreases. This, combined with the dry air that is already in place will lead to efficient radiational cooling. As a result expect lows tonight to be 10 to 20 degrees below normal. We could get close to record lows (see climate section below). && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... High will pass almost directly overhead leading to light and variable winds for much of the region. Despite the sunny conditions, temperatures will remain 10 to 15 degrees below normal as the continental Polar air mass will be entrenched over the region. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... High pressure will have moved east of the area by Thursday night. A warm front will inch towards the area from the west causing clouds to increase over the region. Rains and some mixed precipitation will arrive across the far N/W Friday morning. The models seem to be a bit slower with the arrival time, and this could make the difference in p-type with even a few hours later favoring more rain over mixed. We will continue with a mention of some sleet/freezing rain attm. Other than that, mostly rain N/W with low likely pops by afternoon over the srn Poconos. Limited clouds/precip S/E with temperatures near 60 degrees by afternoon. The weekend looks to be a split with Sat being the better weather day and Sunday looking rather wet. The front will remain to the north Sat with only small chc or slgt chc pops across the far north. The front then sags southward Sunday while low pressure moves along it and approaches from the West. We will carry low likely pops in most areas Sunday. Temperatures well above normal Saturday with 60s north and low 70s South/east. Readings closer to normal Sunday. Unsettled conditions early next week with an upper low and sfc front lingering across the area. We will carry chc pops for both Monday ad Tuesday with this fcst. The north/west counties will be favored for the better chcs for measurable rain. Temperatures early next week should remain a little above normal for late March. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. VFR conditions are expected through the TAF period with few, if any, clouds. Northwest winds will drop off quickly after 00Z, dropping below 10 kt no later than 06Z. By 18Z tomorrow, winds especially at Delmarva and south NJ sites (ILG, ACY, and MIV) could become light and variable as the center of the high passes almost directly overhead. OUTLOOK... Thu night...In general VFR. Low clouds psbl far NW late. Fri...VFR most areas but restrictions psbl with rain and a chance for sleet and freezing rain far N/W Fri morning. Fri night and Sat...mostly VFR. Sat night thru Monday...Showers. restrictions for CIG and VSBY psbl. && .MARINE... Gale force winds will conditions through the early evening hours, before dropping off quickly. Once winds drop below gale force, small craft advisory conditions are expected to continue for most, if not all of the night. By sunrise tomorrow morning, winds and seas should be below SCA criteria. There is a chance for light freezing spray overnight. Still considerable uncertainty as by the time the air temperature gets cold enough to support freezing spray, winds will be dropping off. OUTLOOK... Thursday night...sub-SCA conditions expected. Fri-Fri night...SCA conditions likely on the ocean. Sub-SCA on Del. Bay. Showers mostly north. Sat-Sat night...Conditions diminishing below SCA conditions. Sun-Mon...SCA expected on the Ocean. Sub- SCA on Del Bay. Showers. && .CLIMATE... One or 2 of the following are vulnerable record equaling lows Thursday morning March 23, primarily ABE. Others are listed for reference ACY-13 1875 PHL-14 1885, 1875 ILG-14 1934 ABE-13 1934 TTN-13 1934 GED-16 1959 RDG-14 1906 MPO- minus 8 1912 && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Gale Warning until 11 PM EDT this evening for ANZ450>453. Gale Warning until 8 PM EDT this evening for ANZ430-431-454- 455. && $$ Synopsis...O`Hara Near Term...Johnson Short Term...Johnson Long Term...O`Hara Aviation...Johnson/O`Hara Marine...Johnson/O`Hara Climate...Johnson is the U.S. government's official web portal to all federal, state and local government web resources and services.