Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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381 FXUS61 KPHI 181440 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 940 AM EST Wed Jan 18 2017 .SYNOPSIS... Low pressure forming near the New Jersey coast will intensify eastward, to the south of Cape Cod today. High pressure then builds across the Eastern Seaboard Thursday. Weak low pressure will pass through the region this weekend, and then a much larger and stronger system will impact the area early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Forecast was updated to account for areas of fog reducing visibility to 1/4SM at times, generally southeast of the NJ Turnpike/I-95, due to clearing toward sunrise and light winds within a very moist low-level air mass. We expect the fog to remain in place through late morning, and have issued a Special Weather Statement for the affected area. The Freezing Rain Advisory was allowed to expire at 7 AM, as the bulk of the precipitation had moved out of the area, and temperatures were rising out of the lower 30s. We have maintained a chance of showers through the early afternoon north of I-78. Further south into Delmarva, with the cold pool aloft and abundant moisture, maintained slight chance PoPs across this area. Cool north but becoming milder south during the afternoon as skies brighten a bit toward sunset. North winds near and north of I-78 while a northwest wind becomes gusty 20-25 MPH during the afternoon s NJ and Philly area southward through the Delmarva. Max temps 5 to 10F warmer than normal north and around 10F warmer than normal south. Fcst basis was a 50 50 blend of the 00z/18 NAM/GFS mos guidance. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... Clearing far south though it should remain mostly cloudy elsewhere. Temps 10 to 15 degrees above normal. Northwest wind. Confidence on temps radiating a bit is below average and the lows may be forecast too low. Fcst basis was a 50 50 blend of the 00z/18 NAM/GFS mos guidance. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Our warm and wet pd continues into the extendd. Thu looks to psbly be the nicest day of the pd, with more sun than clouds and temps around or n of 50 degrees in many areas with dry conds under high pres. The high will move ewd Thu night into Fri and wk low pres will bring a shot of shwrs thru by Fri aftn. This shud be a relatively quick shot from aftn into erly eve. Then wk high pres will move back in for later Fri into Sat bringing a return to dry wx. By Sun, a large area of low pres will move out of the srn plains twd the sern states and mid-Atlc. There are still some timing diffs wrt the onset of rain. The GFS is slower movg the precip in than the ECMWF. THe GFS would keep most of SUn dry, not bringing rain in until the aftn, while the EC would bring rain in durg the mrng, especially over srn areas. The CMC is more supportive of the slower soln, so for now will just keep some low pops erly and trend pops upward durg the aftn, but this is a lower than average confidence fcst and Saturday certainly looks to be the better of the two weekend days. The aforementioned low will move to our sw on Mon and Mon is likely to be the wettest day. The guid differs on where the heaviest and steadiest rain may set up, but Mon could end up being a washout, at least for portions of the area. By Tue, the low should be pulling away. The ECMWF ends the precip sooner, while the GFS lingers it somewhat thru the day. However, pops shud at least be decreasing from s to n, if not completely over. Temps look to be much abv nrml thru the pd, about 10 to 15 degrees. With the exception of the highest elevations of the Poconos Mon mrng, all precip that falls durg this pd shud be plain rain. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Today...General IFR conditions this moring will gradually improve to MVFR cigs during the early afternoon with vsby improving to VFR as north to northwest winds gradually increase with northwest gusts vcnty KACY, KPHL, KMIV and KILG of 20-25 kt during the afternoon. Scattered morning showers/drizzle will end early afternoon. Tonight...Probably VFR bkn-ovc cigs aoa 3500 ft though it may scatter out at KPHL southward, especially after 06z. Light northwest wind. OUTLOOK... Thu through Fri mrng...VFR. High pres. High confidence. Fri aftn thru Fri night...Sub-VFR conds psbl in -RA. Mdt confidence. Sat through Sun. Mainly VFR. High confidence VFR Sat. Lower confidence VFR Sun, especially s as RA is psbl. && .MARINE... Marine Weather Statement in effect for all the coastal waters except ANZ450 (near shore waters off Monmouth County) for areas of fog reducing visibility to 1SM at times. This per synoptic pattern, satellite, near shore observations, and web cams. We expect the fog to subside around noontime. A short period of SCA northwest winds expected for this afternoon with winds subsiding early tonight. OUTLOOK... Thu through Sun...Sub-SCA conds expected. Sun night through Mon night...Easterly flow 20-30 KT. SCA conds likely, with gale force winds possible on Mon, mainly on the ocean waters. Tue...Wind shud subside below SCA conds, but seas will remain elevated. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory from 1 PM this afternoon to 9 PM EST this evening for ANZ430-431-452>455. && $$ Synopsis...Nierenberg Near Term...Drag/Franck Short Term...Drag Long Term...Nierenberg Aviation...Drag/Franck/Nierenberg Marine...Drag/Franck/Nierenberg is the U.S. government's official web portal to all federal, state and local government web resources and services.