Marine Weather and Tide Forecast for Merchantville, NJ

NEAR TERM /THROUGH TONIGHT/
215 PM...Our first round of severe weather is finishing up across southern New Jersey and southern Delaware. A second round of severe weather is possible this evening into tonight as another MCS moves east from the southern Ohio River Valley across Virginia and into the DC Metro. This MCS is expected to bring a cluster of storms across the Delmarva tonight, potentially impacting portions of southeast PA and southern NJ again. This MCS also looks to interact with the residual outflow boundary from our severe storms late this morning and early this afternoon. In fact, convection has fired up along this outflow boundary already across central PA. There remains ample untapped instability (2000-3000 J/kg CAPE) across south central PA, northern VA, and the western Delmarva Peninsula. Furthermore, skies have cleared out rapidly this afternoon, allowing for some locations to see some atmospheric destabilization again.
Damaging wind gusts with some possible hail will be the main concerns, but another tornado or two cannot be ruled out with this second round of severe storms. The second round of severe potential will be around 5-9pm.

For Friday night, there may still be some convection ongoing into the evening but this should diminish with time leading to another brief lull. Once again, there could be some low clouds, mist, and fog that form due to the continuing moist environment. The action won't be over though because by later Friday night the main slug of energy more directly associated with low will be approaching and this could bring another MCS into the area sometime either overnight Friday night or Saturday morning. There remains a lot of uncertainty on this though. Otherwise, it will be a mild, muggy night with lows mainly in the 60s.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
Mid/upper level low over the Great Lakes will pivot east on Saturday as a vigorous shortwave tracks across the Mid-Atlantic with northwest flow developing in its wake on Sunday. At the surface, an area of low pressure will slide across Ontario/Quebec by Saturday night before meandering near Nova Scotia on Sunday. A strong cold front will pass through the area late Saturday afternoon into Saturday night.

To start out Saturday, a MCS originating from the lower Ohio Valley is progged to approach our area on Saturday morning. The overall nature of this feature depicted by the latest CAM guidance is that it will be decaying or even dissipate as it approaches our area. A few showers and thunderstorms may be possible through the morning hours especially north and west, but since this feature is mesoscale driven, it's very difficult to depict where this feature may be come Saturday morning. Skies should be partly to mostly cloudy through the morning however, before clearing out by early afternoon.
Temperatures will climb into the 80s for most areas with dew points in the low to mid 60s making it feel quite uncomfortable outside.
The cold front will continue to make its way east through the afternoon where isolated to scattered thunderstorms will re-develop by the afternoon. In addition to the better forcing, we'll have MLCAPE values around 1000-1500 J/kg, DCAPE around 900 J/kg, and modest shear as indicated by point forecast soundings. These parameters will support damaging winds being the primary concern and possibly some severe hail. A brief tornado also cannot be ruled out as some low level shear will be in place. This is in line with the Storm Prediction Center which keeps the entire area in a Slight Risk (Level 2/5). Unfortunately, this threat is conditional and entirely dependent on the morning MCS and how it evolves, so the forecast may vary significantly by this time tomorrow. Nonetheless, the cold front will push off the coast by Saturday night and the threat for storms wanes in addition to the loss of daytime heating.

Sunday is looking like the better half of the weekend as tranquil weather returns with the upper trough moving further east. Partly to mostly cloudy skies are expected with dry conditions and lower humidity. Perhaps an isolated shower is possible north and west, but general thinking is most of the area will stay dry. The one thing to note is winds will increase as diurnal mixing occurs as the area lies wedged between systems resulting in a tightening pressure gradient. Wind gusts up 30-35 mph will be possible. Gusts will diminish into Sunday night under mostly clear skies. Despite the windy conditions, high temperatures should mainly be in the 70s (with 60s in the Poconos).

LONG TERM /MONDAY THROUGH THURSDAY/
By Monday, low pressure over the Canadian Maritimes will begin to move further east into the North Atlantic. At the same time, high pressure will settle over the Mid-Atlantic before moving offshore on Tuesday. Aloft, the area will be situated under northwest flow in wake of exiting upper trough. All in all, a tranquil weather period is in store with mostly clear skies, light winds and dry weather.

By Tuesday night and through the middle of the week, our attention will turn to our next weather system which will take aim at the area. Global and ensemble guidance both feature a deep upper trough moving into the Great Lakes/Northeast region around the middle of the week with a potential coastal low developing before moving up towards New England. This would indicate another period of unsettled weather with periods of rain starting as early as Tuesday night, and more so on Wednesday and Thursday. Still quite a ways out from this potential, so have generally stuck with NBM guidance and capped rain chances at chance (~30-50%).

In terms of temperatures, we'll encounter temperatures around average on Monday, before dipping below average for Tuesday through Thursday as the area remains situated within the deep upper trough.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Rest of today...A lull in showers and thunderstorms this afternoon before another round of storms may arrive late afternoon and early evening. Second round will mainly impact all terminals except ABE. Skies will be mostly clear, but a low scattered deck may cause brief moments of MVFR/IFR conditions right over the terminals. Generally S to SSE flow less than 10 kts for the rest of the afternoon, but stronger gusts in thunderstorms.

Tonight...Any showers/storms diminish through the evening with with the potential for low cigs and low visbys once again due to stratus, mist and fog. Low MVFR or IFR appears likely. More showers and storms could move in late. S to SW winds around 5 knots. Low confidence.

Outlook...

Saturday through Saturday night...Primarily VFR expected. Scattered showers and thunderstorms likely, especially during the afternoon and early evening. Any shower or thunderstorm may cause temporary sub-VFR conditions, gusty winds and/or visibility restrictions.

Sunday through Tuesday...VFR. Gusty winds up to 25-30 kt possible on Sunday. Otherwise, no significant weather expected.

MARINE
Areas of dense fog over the waters likely to be an issue through the first half of Friday. Beyond this time, increasing chances for showers/storms over the waters in the afternoon. Generally sub SCA except any storms could produce locally strong winds.

The risk for some showers/storms over the waters continues Friday night along with the potential for low visbys due to fog.

Outlook...

Saturday through Saturday night...No marine headlines expected.

Sunday through Sunday night...SCA conditions possible due to wind gusts up to 25 kt.

Monday through Tuesday...No marine headlines expected.

TIDES/COASTAL FLOODING
The Coastal Flood Advisory for northwestern Burlington and lower Bucks Counties has been extended until 8 AM Saturday. Minor coastal flooding is expected with the early morning high tide this morning and on Saturday. It's possible minor coastal flooding may occur on Sunday as well, where further extensions may be needed.

For areas of the lower tidal Delaware River near Philadelphia may encounter spotty minor coastal flooding through Saturday, but should fall short of advisory levels.

PHI WATCHES/WARNINGS/ADVISORIES
PA...Coastal Flood Advisory until 8 AM EDT Saturday for PAZ106.
NJ...Coastal Flood Advisory until 8 AM EDT Saturday for NJZ019.
DE...None.
MD...None.
MARINE...None.