Delaware Bay south of East Point NJ to Slaughter Beach DE Marine Forecast
|Tonight...S Winds 10 To 15 Kt. Gusts Up To 20 Kt Late This Evening And Overnight. Waves 2 Ft Or Less. A Slight Chance Of Showers Late This Evening. A Chance Of Showers After Midnight, Then Rain Likely Late.|
|Thu...Sw Winds 10 To 15 Kt. Waves 2 Ft Or Less. Rain In The Morning, Then Rain Likely Early In The Afternoon. A Chance Of Showers Late. Vsby 1 To 3 Nm In The Morning.|
|Thu Night...Nw Winds 5 To 10 Kt. Waves 2 Ft Or Less. Patchy Fog After Midnight With Vsby 1 To 3 Nm.|
|Fri...Nw Winds Around 5 Kt. Waves 2 Ft Or Less. Patchy Fog Early In The Morning With Vsby 1 To 3 Nm.|
|Fri Night...Nw Winds 5 To 10 Kt. Waves 2 Ft Or Less.|
|Sat...Nw Winds 10 To 15 Kt. Waves 2 Ft Or Less.|
|Sat Night...Nw Winds 5 To 10 Kt. Waves 2 Ft Or Less.|
|Sun...Nw Winds 5 To 10 Kt, Becoming Sw In The Afternoon. Waves 2 Ft Or Less.|
|Sun Night...Se Winds 5 To 10 Kt, Increasing To 10 To 15 Kt After Midnight. Waves 2 Ft Or Less.|
|Mon...Se Winds 20 To 25 Kt. Waves Around 3 Ft. A Chance Of Rain In The Morning, Then Rain Likely In The Afternoon.|
|Mon Night...S Winds 20 To 25 Kt, Diminishing To 10 To 15 Kt After Midnight. Waves 3 To 4 Ft. Rain Likely.|
| Area Forecast Discussion|
National Weather Service Mount Holly NJ
336pm EST Wednesday Nov 25 2020
A warm front will lift through the region tonight, followed by a cold front on Thursday, as a weak wave of low pressure tracks through the eastern Great Lakes. A secondary cold front will move through Friday night. High pressure then builds in for the weekend before starting to shift offshore Sunday night. A complex storm system is likely to evolve over the eastern US early next week, and may affect our region for multiple days.
Near Term - Through Thursday
A mid level low was located over the middle Mississippi River Valley this afternoon. The feature is expected to progress eastward across the southern Great Lakes tonight, and New York State on Thursday. The axis of the associated mid level trough is forecast to pass over our region on Thursday afternoon with a surface cold front trailing close behind.
Mid and high level clouds will remain overhead into this evening, with an increase in stratocumulus during that time. The clouds are then expected to lower during the night in the southerly flow as rain approaches from the west.
A 40 to 50 knot low level southwesterly jet is forecast to advect over our region late tonight before shifting off the coast on Thursday morning. The feature will draw a fair amount of moisture into our region. Precipitable was values are anticipated to increase into the 1.2 to 1.4 inch range, especially over the coastal plain.
Rain is expected to become steady toward morning, and it will likely become moderate to heavy at times through about midday on Thursday. As the mid level trough axis approaches from the west, the main moisture feed is forecast to pass off the coast during the early afternoon. As a result, the rainfall rates are expected to decrease at that time, and the rain will become more showery in nature before ending during the mid to late afternoon hours. There may even be some breaks in the cloud cover before sunset on Thursday.
Rainfall totals from tonight into Thursday are expected to be mostly in the 0.3 to 0.7 inch range in our region, with locally higher amounts possible, particularly near the coast.
The south to southwest flow will keep conditions mild. Temperatures are anticipated to rise a bit overnight. Highs on Thursday will likely favor the 60s, except in the Poconos and far northern New Jersey, where readings should not get above the 50s.
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... Mainly benign weather is the story to end the week. Still a progressive pattern in place over the CONUS. In the wake of Thursday's minor system, a dry and warmer than average night is expected. If skies clear out as some guidance suggests, fog development is possible given lingering moisture and lack of any noteworthy push of dry air behind that system. Added a mention of fog to the forecast. Friday sees us in between systems with ridging in place over the East. This will support a solidly warmer than average day with many areas near to above 60 for highs and varying cloud cover, and a warmer than average overnight with lows near 40.
A secondary cold frontal passage is expected for Friday night into Saturday as a shortwave trough moves through the region. This will be a weak and moisture starved front, and looks to come through entirely dry or maybe with just a few sprinkles Friday evening or overnight. The only impact will be to knock the highs down around 5 degrees for Saturday, but that still leaves us with a warmer than average day followed by a seasonably chilly night as high pressure builds in.
Long Term - Saturday Night Through Wednesday
Overview... Expectations remain for a pattern change late this weekend into next week. As is often the case in a big pattern flip, it begins to our west. As ridging builds over the Pacific Northwest and southwest Canada, a strong +PNA will develop. This begins over the weekend, then strengthens early to mid next week as an even stronger ridge builds in over the Northwest. This will force a downstream trough over the eastern and southeastern US beginning late in the weekend and likely continuing through most or all of next week, driving colder air into the southern US. Notably, this pattern is very counter to what would normally be expected in a moderate to strong La Nina. But a good reminder that other aspects of intraseasonal forcing can sometimes overcome the dominant global pattern driver. It is also usually an active, stormy pattern for the East Coast. This will play out next week, as a potentially significant storm develops in the East early in the week, with indications of more in the pipeline behind it.
Dailies... Saturday night-Sunday... Quiet weather holds on to end the weekend, good news for any holiday return travel. A seasonably chilly night is expected Saturday night in the cooler air mass behind the reinforcing cold front. High pressure crests over the area on Sunday with another dry and warmer than average day expected as highs get into the low to mid 50s under mainly clear skies with light winds.
Sunday night-Wednesday... As mentioned above, active weather is likely for this period. It will be a highly complex evolution as the new pattern takes shape. We will be watching two systems which are likely to begin interacting late in the weekend. One is a Canadian clipper low dropping towards the northern Great Lakes. The other is a robust southern stream wave propagating out of the desert Southwest, supported by an anomalously strong subtropical jet. Guidance has given strong indications for days that these systems are likely to phase over the East. However, as is usually the case, this interaction is likely to be complex, and while the general signal between models is fairly consistent, there are significant differences in details and timing.
The recent trend has been for a slightly slower approach of the unsettled weather, which would make sense given the increasingly amplified pattern. Dry weather will most likely hold out through Sunday night, possibly into Monday morning. Assuming the two systems do phase together, it is likely the phased low would track over or west of our region. This should promote wet weather outcomes, with rain likely Monday and Monday night. Gusty winds are also possible as a number of model runs are showing this as a fairly intense low with a strong LLJ moving overhead of us, though this will be dependent on the low track as well. Given the timing of the full moon on November 30, will also have to keep an eye on tidal levels especially if flow during and ahead of the system is more southeasterly than southerly. There is then plenty of uncertainty on how long that system lasts as its associated upper low sits and spins in the area while the surface low fills and weakens. The trend appears to be towards drier, though perhaps not entirely dry, weather Tuesday and Wednesday, with temperatures trending downwards as heigheights fall and colder air spills in on the backside of the low.
By the middle to end of next week, additional unsettled weather is possible as trailing shortwave disturbances rotate into the broader longwave trough in the East. With colder air in place, wintry outcomes may be more favored with time, but given the uncertainty associated with the early week system, changes are likely.
A south to southwest flow will continue on the coastal waters of New Jersey and Delaware through tonight and into Thursday as a cold front approaches from the west. The pattern will likely cause wave heigheights on our ocean waters to build to around 5 feet for late tonight and Thursday. As a result, we have issued a Small Craft Advisory effective from midnight until 6:00pm Thursday.
Outlook... Thursday night-Sunday... Seas on the Atlantic coastal waters may initially linger near 5 ft Thursday night, but will tend to diminish with time. Outside of that, sub-SCA (Small Craft Advisory) conditions are expected. Winds mainly west or northwest with gusts 20 kt or less, shifting to southerly on Sunday. Seas 2 to 4 ft.
Sunday night-Monday... Winds and seas will likely begin to increase ahead of a storm system. Marine headlines are likely for most of early next week.
NOAA Mount Holly NJ Office: Watches - Warnings - Advisories
PA...None. NJ...None. DE...None. MD...None.
Small Craft Advisory from midnight tonight to 6pm EST Thursday for ANZ450>455.