000 FXUS61 KPHI 271033 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 633 AM EDT Mon Jun 27 2022 .SYNOPSIS... A cold front will cross the region today bringing numerous showers and thunderstorms to the area. Seasonably cool and dry high pressure will arrive in the wake of the front on Tuesday before dissipating into Wednesday. Dry conditions and fair weather is then expected to continue through Friday with warming temperatures and increasing humidity as the week progresses. A slow-moving cold front will move into the the region on Saturday and linger through Sunday resulting in unsettled weather for the holiday weekend with showers and thunderstorms likely. && .NEAR TERM /THROUGH TONIGHT/... Morning forecast mostly on track. Some showers moving into Berks county and portions of the Lehigh Valley, and another small batch of showers is developing over the Delaware Valley. These showers will continue to develop as the morning progresses. Will make minor adjustments to hourly grids based on latest surface obs. Otherwise, high pressure is anchored off the Eastern Seaboard. Surface low pressure is just east of the Hudson Bay, and a cold front extends out from that low down through western New York and the Ohio Valley. A closed H5 low is just west of the surface low, and troughiness extends back through the Great Lakes, with another weather surface cold front associated with it. Southerly flow ahead of the cold front will usher a warm and humid air mass into the region, though temperatures today will be much cooler than Sunday due to abundant cloud cover and showers associated with the passage of that first cold front. Dew points will be well in the 60s to around 70, and as a result, PWATs will be in excess of 2 inches. Locally heavy rain is possible from time to time, and although there may be some localized poor drainage flooding, not expecting widespread flooding or flash flooding. Surface-based CAPE values will be up around 1000 J/kg, especially in portions of southeast New Jersey as temperatures warm into the 80s ahead of the cold front. This will be enough to allow for scattered thunderstorms, but not expecting severe weather today. Initial cold front passes through in the late afternoon, and showers taper off from west to east. The front gets hung up along the coast, and showers may linger into this evening. The secondary front passes through this evening, pushing the initial front out to sea, and showers come to an end. A cooler and drier airmass spreads into the region tonight as high pressure builds in from the west. Dew points drop into the 40s in the southern Poconos and in the 50s elsewhere. High today will be in the upper 70s to low 80s, and then lows tonight drop into the 50s and low 60s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Zonal flow will prevail in the wake of a departing shortwave trough on Tuesday. A mid-level trough axis will eject eastward out of the Great Lakes region early Wednesday passing across the area later in the day. At the surface, seasonably cool and dry high pressure will settle across the region on Tuesday and then dissipate into Wednesday with a Bermuda high remaining offshore. Temperatures Tuesday and Tuesday night will be on the order of 5-8 degrees below normal along with dewpoints in the mid 50s making for a rather pleasant early summer day. Winds will be from the northwest around 5-10 mph becoming calm overnight. Decidedly the pick of the week. On Wednesday, southwesterly flow will begin advecting warmer air into the area rebounding temperatures to near normal. Dewpoints will still be in the mid to upper 50s, so it will still be a pretty nice and seasonable day overall under mostly sunny skies. The trough axis passing across the area during the late afternoon and evening could result in a rouge shower near or north of I-78, but the antecedent conditions will be rather dry. Thinking this activity would be nothing more than a few sprinkles (if anything at all), thus we do not have any precipitation chances mentioned in the forecast. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Thursday and Friday will see a gradual warming trend as 500 mb heights begin to increase with ridging building into the area. Highs on Thursday will be in the mid to upper 80s, with an outside chance for 90 in the urban corridor. Friday will be a bit warmer, with higher confidence in temperatures over 90 degrees. 850 mb temperatures are expected to be a bit higher compared to Thursday, likely sitting in the 17-20C range. Still looking dry overall for these two days, however with Bermuda high pressure sitting offshore, moisture will increase as we progress through the end of the week. Dewpoints will gradually rise, eventually getting into the upper 60s by Friday. Ridging will flatten out by late Friday as the weekend turns unsettled. The holiday weekend pattern will turn active as a mid-level trough and surface cold front approach the region. Atmospheric moisture will increase further, with PWATs getting into the 1.5 to 2 inch range. With some instability in place as well, there will be a chance for some thunderstorms. Slight chance PoPs come into the forecast for far northwestern zones on Saturday morning, with chance to likely PoPs coming in for parts of the region during the afternoon. Guidance continues to hint at a rather slow progression of the front (which typically stall out across our area in these setups), which will likely keep active and unsettled weather through Sunday as well. The GFS remains the most progressive solution with the front clearing the area by Sunday morning, but this is an outlier and thus the Sunday forecast continues to maintain likely PoPs as well. A slower/stalling frontal boundary would set us up for a potential excessive rainfall event given the high PWats, so this period will need to be monitored closely for any potential holiday weekend impacts. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Today...MVFR CIGs developing throughout. SHRA with scattered TSRA throughout the day with MVFR VSBYs. Conditions improve to VFR from west to east. SW winds around 10 kt, becoming W through the afternoon. Moderate confidence. Tonight...VFR. NW winds 5 to 10 kt. High confidence. Outlook... Tuesday through Thursday...VFR. Winds northwesterly on Tuesday will become west to southwesterly for Wednesday and Thursday around 5-10 kts. Light to calm winds at night. High confidence. Friday...VFR. South to southwesterly winds 10-15 kts. High confidence. && .MARINE... A tight pressure gradient forms between high pressure off the Eastern Seaboard and an approaching cold front. SW winds will increase to 15 to 20 kt with gusts to 25 kt through the day along with seas building to 4 to 5 ft. Small Craft Advisory remains in effect through late afternoon. VSBY restrictions in showers and scattered thunderstorms. Winds turn NW tonight at 10 to 20 kt. Seas diminishing to 2 to 4 ft. Outlook... Tuesday...Sub-advisory conditions expected. Initially northerly winds will shift to the south around 5-10 kts. Seas 2-3 feet. Fair weather. Wednesday through Thursday...Sub-advisory conditions expected. South to southwesterly winds 10-15 kts. Seas 2-3 feet. Fair weather. Friday...Winds and seas building to near advisory criteria, especially into the afternoon. Southerly winds 15-20 kts with gusts up to 25 kts and seas 3-5 feet. Fair weather. Rip Currents... SW winds will range from 15 to 20 mph today before turning NW tonight. However, there will be a New Moon on Tuesday. As a result, there is a MODERATE risk for the development of dangerous rip currents at New Jersey beaches today and a LOW risk at Delaware beaches. With high pressure building in from the west, there is a LOW risk for the development of dangerous rip currents at New Jersey and Delaware beaches on Tuesday. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ450>455. && $$ Synopsis...Staarmann Near Term...MPS Short Term...Staarmann Long Term...Hoeflich/Staarmann Aviation...MPS/Staarmann Marine...MPS/Staarmann