684 FXUS61 KPHI 311819 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 219 PM EDT Sun Mar 31 2019 .SYNOPSIS... A cold front will cross the area by later today. High pressure from the Ohio Valley will build across the area Monday and then move offshore by Tuesday. A coastal low will develop off the Carolinas Tuesday, then move east of our area Tuesday night and part of wednesday. High pressure will arrive for Thursday, then another low may bring unsettled conditions for the close of this week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... For the 1230 PM update, showers continue to work their way eastward as the cold front is now nearing the coast. A quick wind shift to the west and northwest is occurring in the wake of the cold frontal passage. The PoPs were adjusted mainly based on radar trends. The hourly temperature, dew point and wind grids were adjusted based on the latest observations and trends. Cooling is arriving from the west as cold air advection kicks in, therefore the highs for the day looked to have already occurred. Some clearing will start to arrive from west to east by later this afternoon. While the strongest cold air advection is not expected until tonight, there will still be enough cold air advection to result in temperatures being steady or even falling some this afternoon. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... A secondary cold front is expected tonight, which will usher in stronger cold air advection. There is some chance for flurries in the Poconos, but otherwise, this frontal passage looks to be dry. However, one impact of the front overnight is that winds will stay breezy for much if not all of the night. Therefore, wind chill values overnight could be in the teens for much of the region. && .LONG TERM /MONDAY THROUGH SATURDAY/... Monday thru Tuesday...Generally fair weather with below normal temperatures, especially Monday. Highs Monday mostly in the 40s and low/mid 50s for Tuesday. Increasing clouds Tue afternoon as the next system approaches. Tuesday night thru Wednesday...A coastal system will strengthen and move east of our (land) forecast area. Most of the latest guidance suggests that the region will get brushed by the NW edge of the system with some clouds and light rain. Consequently, we have continued with the chc pops across the S/E areas and kept the mention of slgt chc pops elsewhere. It wouldn't take much of a turn for the system to bring a soaking rain to the ern areas, but the trends do not show this yet. The 00Z GFS, in fact, keep measurable QPF offshore. Wednesday afternoon thru Thursday...More high pressure and dry weather expected. Milder with readings around 5 degrees above normal. Thursday night into Saturday...More unsettled conditions expected as a H5 trough and sfc low approach from the west. Look like it may cut up into the Great Lakes and bring a cold front thru Fri or Fri night. Plenty of time to work out the details since there is some model disagreement at this period. High chc pops and a few low likely pops for Fri/Fri night look OK for now. Mild temperatures should prevail and last into next weekend. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...Mainly VFR conditions expected. Showers will end from west to east by early evening. West to northwest winds around 10 to 15 knots with gusts up to 25 to 30 knots through this evening. Gusts will continue overnight but should drop down closer to 20 to 25 knots. Monday...VFR conditions expected. West to northwest winds around 10 to 15 knots with gusts of 20 to 25 kt. Winds will start to diminish towards evening. Outlook... Monday night...VFR conditions expected. Northwest to west winds around 10 knots or less, becoming light and variable overnight. Tuesday...VFR conditions expected. Increasing cloudiness. East to southeast winds less than 10 knots. Tuesday night...Mainly VFR conditions expected. South southeast winds less than 10 knots. Rain showers with sub-VFR conditions possible overnight. Wednesday through Thursday...VFR conditions expected. Northwest winds around 10 knots on Wednesday, becoming light north to northwest on Thursday. Thursday night through Friday...Southeast winds around 10 to 15 knots. Rain showers possible Thursday night and continue through Friday, with MVFR or lower conditions possible. && .MARINE... Expect an abrupt shift to west northwesterly winds early this afternoon. With this shift, expect an increase in winds, gusting above 25 kt for much of the afternoon. The strongest winds are expected this evening into the overnight hours. Gale force gusts are becoming increasingly likely for the lower Delware Bay and the nearby coastal waters. Therefore, a gale watch has been issued for these locations. For the rest of the waters, expect northwesterly gusts around 30 kt for much of the night. Outlook... Monday...SCA conditions diminishing. Fair. Monday night/Tue...Sub-SCA. Fair Monday night with a chc for rain Tue. Tue night thru Wednesday night...SCA expected. Chc for rain. Thu/Thu night...Mostly sub-SCA. Fair. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ450>452. Gale Watch from 6 PM EDT this evening through late tonight for ANZ431-453>455. Small Craft Advisory until 6 PM EDT this evening for ANZ453>455. Small Craft Advisory until 6 AM EDT Monday for ANZ430. && $$ Synopsis...Gorse/O'Hara Near Term...Gorse/Johnson Short Term...Johnson Long Term...O'Hara Aviation...Meola Marine...Johnson/O'Hara