724 FXUS61 KPHI 292045 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 345 PM EST Sat Jan 29 2022 .SYNOPSIS... The strong coastal storm will continue to move northeast reaching the Canadian Maritimes by tonight. High pressure returns for the end of the weekend and early next week. Another low pressure system may approach our region late next week. && .NEAR TERM /THROUGH SUNDAY/... As of mid afternoon, intense low pressure was located east of Cape Cod and continuing to move NE towards the Canadian Maritimes. As this occurs, back edge of snowfall continues to come to an end from west to east and has cleared most areas expect portions of northern NJ south towards Monmouth and Ocean Counties. Even here though, any additional accumulation will be less than an inch so the remaining storm headlines will be allowed to expire at 4 PM. Speaking of accumulations they have been impressive with upwards of 12 to 18+ inches of snowfall along the coast of NJ. Totals taper progressing west and northwest with around 6 to 8 inches around Philadelphia. A full report of the snowfall accumulations can be found in our latest Public information statement at the top of our Home Page under News Headlines. As we go through the late afternoon into early this evening, the last of the snow will exit our eastern zones as the low continues to move away with the main story shifting to the winds and cold. Expect NW winds continuing to gust 25 to 35 mph with some higher gusts up to 45 mph along the coast. Despite the storm moving away these strong winds will be supported by the strengthening cold advection pattern and associated substance. Despite the snow having ended, the wind will continue to cause blowing and drifting snow in places with associated travel impacts. The winds will ease off with time by the mid to late evening period into the overnight but won't die down entirely as they stay NW generally at least 10-15 mph. This will result in continuing wind chills near or below minus 20 in the southern Poconos where a Wind Chill Advisory remains in effect. Farther south, wind chills will mainly be in the -5 to +5 range so still quite cold! By Sunday morning, the storm will be well to our north and east over Atlantic Canada with weak ridging starting to build in from the south and west resulting in winds continuing to diminish. So the upshot is it will be a much more tranquil day, but still cold, with morning sunshine giving way to some increasing clouds in the afternoon as an upper level disturbance approaches. Highs will be mainly in the 20s except teens in the southern Poconos. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... For Sunday night, an upper level disturbance in the flow moves through but there doesn't look to be enough deep moisture to yield any precip. There still may be some cloudy periods though. It will be very cold too with lows ranging from the single digits north to teens south. For Monday, aformentioned wave departs with upper level ridge crest moving into the eastern Great Lakes and high pressure building in to our north. The airmass will modify as this occurs with highs moderating to the 30s south (20s north over the southern Poconos) under variable cloud cover. Monday night into Tuesday, things get a little more complicated as the pressure center to our north moves east into Atlantic Canada causing low level winds to turn onshore (though they will be light). Combined with the snowpack, this moist low level flow could result in the development of fog or low stratus by the Monday overnight period into Tuesday morning. Confidence not high enough to include in the gridded forecast at this time but that potential is there. This set up will also result in continuing modification of the airmass with Tuesday's highs mostly in the upper 30s to low 40s except closer to freezing in the Poconos. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... The forecast for the latter half of the week remains nearly on track and was updated with the latest guidance. The main focus on the long term is the low lifting northeast out of the lower Mississippi Valley to western New England Wednesday into Thursday night. This will be our next chance for precipitation across the region, though the precipitation with this system will be mostly rain, possibly changing to snow if the precipitation lingers beyond a cold frontal passage on Thursday night. If we stay in the warm sector however, the concern becomes heavy rain. Given that many areas will have just had fresh snow melt (or possibly even some snow pack remaining), it may not take much to raise flooding concerns. With the forecast staying on the warmer side, maximum temperatures on Thursday will be in the 50s for almost all of the region. The cold front should cross our region Thursday night into Friday. The latest guidance depicts 6 to 12 hours of precipitation behind the cold frontal passage, so we will see if that is enough to bring another chance for snow to the region Friday and early Friday night. A cold air mass settles in place for the end of the week with tranquil conditions. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Through today...Surface low pressure continues to deepen off the coast of MA and is slowly heading northeast. Snow is slowly coming to an end from southwest to northeast this afternoon, but has been slightly slower to clear than initially forecast as another weak secondary low has formed southwest of the main low. These lows will slowly merge and pull away from the region. As the snow exits the region, cigs and vsbys will quickly start to recover, but the gusty winds will persist. Guidance has been very consistent with showing a slight down tick in the winds this afternoon and another brief surge in the winds this evening. Wind gusts from momentum transfer are indicating another period of gusts up to 30 kts possible. The continued cold air advection will also keep lapse rates rather steep, which means wind gusts will likely continue to around 6z or so. Tonight...Winds will slowly diminish, but stay elevated early tonight. Finally, winds will start to relax and slowly back from the west by dawn. Outlook... Sunday...VFR conditions expected as high pressure builds in from the west. West winds will continue to diminish and back from the southwest. High confidence. Sunday night into Monday... An upper level disturbance will approach the region from the west. Dry conditions are expected, but there could be some transient MVFR cigs. Low confidence. Monday...The upper level disturbance will be exiting the region with an inverted trough placed over central NJ. When this type of setup exists (with a snow pack in place), there is the potential for some fog/ low stratus. As of now, the latest GFS guidance tends to be way to bullish here, but this will have to be watched. Low confidence. Tuesday...Surface high pressure centered over Quebec will be nudging into the region Tuesday morning with winds mainly out of the north or northeast. Transient IFR/ MVFR cigs (stratus) possible across the southern terminals. Low confidence. Wedensday...MVFR/ VFR conditions expected as surface high pressure retreats eastward. Winds will veer from the southeast ahead of an approaching cold front. Moderate confidence. Thursday...The surface cold front will then stall north of the region and retreat north as a warm front as another low pressure approaches from the southwest. Low confidence. && .MARINE... No major changes to the Marine forecast with the mid afternoon update as very strong wind and high seas continue due to the storm. Seas have been upwards of 8 to 13 feet with winds gusting 40 to 50+ knots. A storm warning remains in effect for the Atlantic waters and the southern DE Bay for the daytime hours, with another gale warning likely to be required for tonight after the storm warning ends. The gale warning continues for upper Delaware Bay through tonight (where storm-force winds are not expected). A brief period of advisory conditions is then expected Sunday morning, before winds diminish to sub-advisory thresholds by Sunday afternoon. Heavy snow occuring over the waters will be ending over the next several hours however freezing spray will develop into this evening, with moderate accretions likely tonight into early Sunday afternoon. A freezing spray advisory remains in effect for this period. Outlook... Monday night through Thursday... winds and seas should stay below SCA criteria Monday night through Wednesday night. SCA conditions are possible Thursday. && .TIDES/COASTAL FLOODING... The next high tide cycle is the lower of the two high tides with all sites forecast to remain well below minor flooding. The subsequent high tide cycle Sunday morning will be close to minor levels, with some residual high water remaining in Barnegat Bay. As of current, this looks to be spotty minor flooding as surface winds quickly back from the northwest. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...Winter Storm Warning until 4 PM EST this afternoon for PAZ106. Wind Chill Advisory until 10 AM EST Sunday for PAZ054-055. NJ...Winter Storm Warning until 4 PM EST this afternoon for NJZ008>010-012-015-019. Blizzard Warning until 4 PM EST this afternoon for NJZ013-014- 020-022>027. DE...None. MD...None. MARINE...Storm Warning until 6 PM EST this evening for ANZ431-450>455. Freezing Spray Advisory until noon EST Sunday for ANZ430-431- 450>455. Gale Warning until 6 AM EST Sunday for ANZ430. && $$ Synopsis...Fitzsimmons/Johnson Near Term...Fitzsimmons Short Term...Fitzsimmons Long Term...Franklin Aviation...Haines Marine...Fitzsimmons/Franklin Tides/Coastal Flooding...WFO PHI