817 FXUS61 KPHI 061843 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 140 PM EST Wed Nov 6 2019 .SYNOPSIS... High pressure will build over the region today, before shifting off shore tonight. A cold front will approach the region tomorrow. As it does so, a low pressure system is expected to develop then lift along the front, with both features crossing our region late Thursday into Thursday night. A large surface high will be the dominant feature through the weekend. Another cold front is expected early in the next work week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 930 AM Update: the nocturnal surface-based inversion is eroding quickly the morning and faster than the forecast portrayed. Therefore, temps have rebounded quickly to near 50 degrees at this hour. Additionally, we've tapped into the slightly stronger winds just above the surface, so winds have picked up a bit this morning with some gusts showing up in the latest observations. I have updated the forecast to reflect these trends. Otherwise, the forecast remains on track for a dry and pleasant autumn day with highs generally in the low to mid 50s. High pressure near West Virginia this morning will crest across the Middle Atlantic later today. Fair weather is expected thru the day with mostly sunny skies. Temperatures today will be cooler than Tuesday with readings 5 degrees below normal. Highs will range from the upper 40s/low 50s across the N/W areas to the mid 50s with a few upper 50s over Delmarva and metro Philadelphia. Winds will be gentle from the NW to W around 10 mph this afternoon. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... The high will move offshore tonight. A continuation of fair and cool weather is expected. Under mainly clear skies, temperatures will drop into the 30s in most areas. Winds will be light. Thursday and Friday: The trend that started with yesterday's model runs, with a later cyclogensis and consequently less snow in our region, has continued with the 00Z model runs. It now appears that a majority of the precipitation in our area will be ahead of and with the front, meaning it will be mostly rain. A brief period of snow is possible north and west of the fall line, but with the possible exception of the higher terrain of the southern Poconos and Northwest New Jersey, accumulating snow appears unlikely. Breezy conditions behind the front will favor quickly drying roadways. Temperatures will fall into the 30s by Friday morning. One thing to note, forecast is higher than GFS or GFS MOS guidance with temperatures, because the GFS is by far the most progressive with the front, which has been a recent bias with the GFS. Significant dry and cold air advection is expected Friday, so highs on Friday are expected to be 15 to 20 degrees below normal, in the 30s and 40s. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... High pressure will build into the region Friday night and eventually shift off shore Sunday. Temperatures will remain well below normal on Saturday, but by Sunday, southwesterly return flow will result in a significant warming trend, with highs in the 40s and 50s. The pattern Monday through Wednesday has some similarities to the Thursday/Friday pattern. A cold front is expected to cross the region Monday afternoon or evening and cyclogenesis is expected along the front. Currently guidance indicates a period of a rain/snow mix will occur across the region Monday night into Tuesday night with the greatest chance for some snow north and west of the Philadelphia metro area. No precipitation is forecast Wednesday but temperatures will continue to be much below normal. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Today...High pressure across the region. VFR with only some high clouds from time to time. Northwest winds have picked up this morning with some occasional gusts, but will weaken becoming west less than 10 kts into the afternoon. Tonight... VFR. Mostly clear. Light winds favoring W or SW early then S late. Outlook... Thursday and Thursday night...VFR conditions will lower to MVFR (primarily for ceilings), and localized IFR conditions are possible especially Thursday afternoon and evening with rain in the area. Some very light snow is possible at KRDG and KABE. Abrupt shift to northwesterly winds Thursday night, with gusts up to 20 kt. Moderate confidence on the overall pattern, low confidence on the details. Friday...Mostly VFR conditions. Northwesterly winds 15-20 kts with gusts 25 - 30 kts possible. Friday night through Monday...VFR conditions expected. && .MARINE... High pressure will be across the waters today before moving east tonight. Fair weather is expected thru the period. Winds will be mostly northwest around 10 knots this morning before decreasing later today. Tonight, winds will switch around to southwest but remain under 10 knots. Seas mostly 2 to 3 ft today and tonight. Outlook... Thursday...southwesterly winds will gradually increase, and wind gusts above 25 kt are possible on the coastal waters Thursday afternoon. Thursday night and Friday...an abrupt shift to northwesterly winds is expected with a cold front Thursday night. Wind speeds will increase quickly behind the front as well, and gale force gusts are possible, especially Friday morning. Saturday...winds and seas should stay below SCA criteria. Sunday...Southerly wind gusts could reach SCA criteria, primarily on the Atlantic coastal waters, and primarily afternoon. Monday...Winds become northwest by afternoon, increasing to near SCA Monday night. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...Johnson Near Term...O'Hara/Staarmann Short Term...O'Hara Long Term...Johnson/Franklin Aviation...Johnson/O'Hara/Staarmann Marine...Johnson/O'Hara