Marine Weather and Tide Forecast for Folcroft, PA

NEAR TERM /THROUGH TUESDAY/
Static and dreary weather pattern persists as rounds of showers, mist, and drizzle continue this afternoon with the stalled frontal boundary remaining located over Virginia. RH values in the 0-2 km layer remain above 90% with PWATs ranging between 1.50-1.75" with deep warm cloud depths. This will support periods of heavy rainfall with efficient rain rates despite overall minor accumulation totals.

This will be the story through this evening and Tuesday as well as an area of low pressure approaches from the west tonight causing the stalled boundary to lift north as a warm front on Tuesday. The location of the front will remain nearly stationary tonight however, but will begin making steady progress on Tuesday, likely reaching the southernmost portions of our area by Tuesday evening. With this in mind, we'll continue to experience several rounds of showers and mist/drizzle through tonight and perhaps some fog developing as well, especially near the coast. Lows tonight will range from the upper 50s to mid 60s areawide.

Tuesday will feature much of the same through the morning hours, however we should begin to see at least improvement in the afternoon as the warm front approaches. Skies may feature some brightening with potentially a few brief breaks of sun. There will be some energy aloft passing through during the afternoon coinciding with the approaching warm front so another round of showers and possibly isolated thunder should occur ahead of the front. Highs will vary across the region with upper 60s to mid 70s across northern areas with upper 70s to mid 80s across southern areas.

SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
The pattern finally starts to shift as we go through the short term period. For Tuesday night, a warm front lifts through the area along with a disturbance aloft. This will bring some showers and thunderstorms by later in the evening into the overnight. Some of these could produce heavy downpours as PWAT values rise to around 2 inches. Best chances for showers/storms appears to be for areas near and N/W of the urban corridor. It will be a warm and muggy night with lows generally in the middle to upper 60s and dew points not much below these values.

Wednesday we really get into the heat and humidity as the SW flow kicks in. Mainly cloudy skies to start the day should give way to some sunshine by afternoon, especially over central and southern parts of the CWA Expect highs for most areas getting into the mid/upper 80s to low 90s with dew points into the 70s. As a result of this, heat indicies over SE PA, interior southern NJ, and Delmarva could reach as high as the mid to high 90s. As we get into Wednesday afternoon, there looks to be a surface trough setting up over the area and this should help trigger some showers and potentially severe thunderstorms. In fact Wednesday's threat for severe weather appears to be increasing relative to previous forecasts as ML CAPES look to reach 1500-2500 j/kg with modest shear. Damaging winds look to be the biggest threat.

Storms diminish Wednesday evening with an even warmer, muggier night on tap for Wednesday night compared to Tuesday night. By Thursday morning, lows will only be down into the mid upper 60s north and low to mid 70s over SE PA, central/southern NJ, and Delmarva.

Thursday still looks to be the day featuring an even greater severe weather threat. As we go through the Wednesday night and Thursday timeframe, low pressure will be tracking eastward through Ontario and Quebec and this will help continue to pump in hot, humid air into the area with a continuing SW flow. This SW flow and associated heat will also be aided by the Bermuda high setting up over the western Atlantic. Highs Thursday look to be similar to if not a couple degrees warmer than Wednesday so heat impacts could start to build, especially since there will be so little relief at night.
Once again, max heat indicies should be in the mid to upper 90s over portions of SE PA, central/southern NJ and Delmarva. Regarding the severe weather threat, a cold front will be approaching in the afternoon and then moving through in the evening. ML CAPE values look to top out around 2000+ j/kg with deep layer shear of 30-40+ knots. While this is still a few days out this set up could favor a potentially higher end severe weather event with numerous instances of damaging winds. Again confidence regarding these details is still not high as it will depend on the timing of the front and the strength of a disturbance aloft, etc. Right now, timing for storms and associated severe weather looks to be afternoon / evening.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
For Thursday night, showers/storms diminish by the overnight period as the cold front moves offshore and this will be followed by high pressure building in to our south on Friday. Friday will be cooler and less humid with highs generally in the 80s under partly to mostly sunny skies. An upper level disturbance moving through late day could trigger a few storms in the Poconos but otherwise it should be dry.

As we head into the weekend and early next week, it should be rainfree much of this time as an upper level ridge builds over the east. Saturday will still feature highs in the 80s and humidity levels that are not too high but by Sunday and Monday high heat and humidity looks to really build as the upper level ridge strengthens.
By next Monday, highs could be into the mid 90s for many areas with heat indicies over 100! While most of the Saturday through Monday period should be rain free, there may be a weak impulse that moves through along a warm front bringing a few showers/storms Saturday night into early Sunday. We have POPs generally around 20 to 30 percent for this time period but otherwise POPs are below 15 percent.

AVIATION /21Z MONDAY THROUGH SATURDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Rest of Today...IFR conditions to continue with little improvements.
Periods of rain showers, mist and drizzle expected. East-northeast winds around 7-12 kt. Moderate confidence.

Tonight...IFR conditions expected early with LIFR conditions developing at all terminals generally between 03-05Z. In addition to mist, patchy fog is possible as well, but confidence is lower in this occurrence, so left out of the TAFs for now. East-northeast winds around 5 kt becoming LGT/VRB at times. Low-moderate confidence overall.

Tuesday...LIFR/IFR conditions expected through the morning, potentially lifting to IFR/MVFR in the afternoon. Periods of mist expected early, with a slight chance of showers during the afternoon. Northeast winds will gradually become south-southeast around 3-8 kt. Low-moderate confidence.

Outlook...

Tuesday night...Sub-VFR CIGs /VSBYs in fog, stratus, and scattered SHRA.

Wednesday through Wednesday night...Becoming mainly VFR by midday Wednesday. Scattered TSRA possible with brief sub-VFR conditions, mainly in the afternoon and evening.

Thursday through Thursday night...VFR in the morning. Scattered afternoon and evening SHRA/TSRA with relatively brief sub-VFR conditions.

Friday through Saturday...VFR.

MARINE
No marine headlines are in effect through Tuesday. East-northeast winds around 12-17 kt with gusts up to 20 kt today will diminish to around 10-15 kt tonight. Winds will gradually turn from northeast to southeast on Tuesday around 5-10 kt. Seas of 3-4 feet. Periods of showers, drizzle, and mist to continue through tonight.

Outlook...

Tuesday night through Saturday...Sub-SCA conditions expected through the week with max wind gusts below 20 kt and seas in the 2 to 4 ft range. VSBY restrictions in showers and fog through Tuesday night.
Afternoon and evening showers and thunderstorms possible on Wednesday and Thursday with locally stronger winds and higher waves.

Rip Currents...

For Tuesday, winds turn to be a bit more east-southeasterly and decrease to around 10 MPH. Swell remains onshore but the number of swell groups look to consolidate with the period decreasing to 6-7 seconds. Breaking waves in the surf zone look to decrease to 2-3 feet as a result. The combination of these factors look to lead to a decreasing risk for the development of rip currents, so at this time a LOW risk is forecast for the beaches south of Atlantic City and MODERATE for the northern Jersey Shore beaches.

For Wednesday, winds increase to 10-15 mph with the swell period remaining around 6-7 seconds. However, winds and swell turn to become more shore parallel out of the south-southwest. As a result, breaking waves in the surf zone look to decrease to mainly 2 feet or less. Therefore, a LOW risk for the development of rip currents is forecast for all beaches on Wednesday.

For specific beach forecasts, visit weather.gov/beach/phi

PHI WATCHES/WARNINGS/ADVISORIES
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.