Delaware Bay north of East Point NJ to Slaughter Beach DE Marine Forecast
|Today...W Winds 10 To 15 Kt, Becoming Nw 15 To 20 Kt Late. Waves Around 3 Ft. Showers Late This Morning And Early Afternoon. A Chance Of Showers Late.|
|Tonight...Nw Winds 15 To 20 Kt With Gusts Up To 25 Kt, Diminishing To 10 To 15 Kt With Gusts Up To 20 Kt After Midnight. Waves Around 3 Ft Until Early Morning, Then 2 Ft Or Less.|
|Sat...Nw Winds 5 To 10 Kt, Becoming Sw In The Afternoon. Waves 2 Ft Or Less. A Chance Of Rain Late.|
|Sat Night...Se Winds 5 To 10 Kt. Waves 2 Ft Or Less. Rain.|
|Sun...Nw Winds 10 To 15 Kt, Increasing To 15 To 20 Kt In The Afternoon. Gusts Up To 25 Kt. Waves 2 Ft Or Less, Then Around 3 Ft In The Afternoon. A Chance Of Rain In The Morning.|
|Sun Night...Nw Winds 15 To 20 Kt, Becoming W 10 To 15 Kt After Midnight. Gusts Up To 25 Kt. Waves Around 3 Ft.|
|Mon...W Winds 5 To 10 Kt. Waves 2 Ft Or Less.|
|Mon Night...Sw Winds 5 To 10 Kt. Waves 2 Ft Or Less.|
|Tue...S Winds 5 To 10 Kt. Waves 2 Ft Or Less.|
|Tue Night...S Winds 10 To 15 Kt. Waves 2 Ft Or Less.|
Area Forecast Discussion|
National Weather Service Mount Holly NJ
640am EST Fri Nov 22 2019
Low pressure will move from Quebec toward the Canadian Maritimes through today pushing a cold front across our region. The next low pressure system will then develop across the southern Appalachians and pass just to the south of the forecast area and offshore late Saturday into early Sunday. High pressure then returns into early next week before another system may potentially impact the region by the middle of next week.
Near Term - Until 6pm This Evening
Surface low entering Quebec early this morning will race east- northeast today, reaching the Canadian Maritimes by Saturday morning. A cold front will extend south-southwest from the low and should move rapidly through the area this afternoon into early this evening. As it does so, a weak southern-stream perturbation will race into the Mid-Atlantic, providing increased lift near the frontal zone. The timing of this will be critical, because rainfall accumulations will be heavier should this stronger ascent outrun the front. Generally, this is expected to occur in the southern CWA, where the front will be slowest to pass through. However, the increased ascent looks to be strong enough across the area to justify increasing Probability of Precipitation to likely from around midday through the afternoon. The highest Probability of Precipitation are generally along/southeast of the urban corridor, where the added lift from the southern-stream system will be strongest. Think precipitation will likely be done (or nearly so) for the area by 4 pm, with quick clearing thereafter as cold/dry advection set(s) in.
Quantitative Precipitation Forecast should be fairly light with this system, generally under a quarter inch. Locally higher totals may occur in Delmarva and southern New Jersey, depending on the extent of the southern-stream perturbation's influence on the generation of precipitation. Temperatures will be much too warm for anything other than liquid precipitation.
In advance of the front, strong warm advection should keep temperatures mild, likely 5-10 degrees above seasonal averages today. This will be mitigated to some degree by the overall cloudiness, but enhanced by fairly strong mixing as surface winds increase and gust to around 20-25 mph this afternoon. After frontal passage, winds will switch to northwest and increase, with gusts approaching/exceeding 30 mph in many locations.
Short Term - 6pm This Evening Through 6am Saturday
With the rapid exit of today's system offshore, a brief period of high pressure will begin tonight. The high should be centered near or just southwest of the area by 12z Saturday, which should aid in the rapid decrease of winds this evening. With clearing skies and a colder source region of the upstream environment, think tonight will be rather chilly. Have generally kept temperatures on the cold side of guidance, though possibly not cold enough (yet) in the more sheltered rural/valley locations in eastern PA, northern NJ, and the Pine Barrens. Specifically, expecting lows near 20 in the Poconos, near freezing in the urban corridor and along the coast, and in the mid to upper 20s in most other locations.
Long Term - Saturday Through Thursday
The main story early in this period continues to be the low pressure system still forecast to affect the region late Saturday into Sunday. To start the period early Saturday, a ridge of high pressure will be located along the east coast with an area of low pressure associated with the southern stream over Tennessee. The day will get off to a mostly clear and chilly start however through the course of the day the high will move off the coast while low pressure approaches as it moves NE into the Ohio Valley. This will lead to skies becoming mostly cloudy through the afternoon however the timing of the system has slowed somewhat so precipitation looks to most likely hold off until the early evening time frame. Highs Saturday generally range from around 40 over the southern Poconos to the upper 40s over the Delmarva.
For Saturday night, aformentioned low moves NE with the primary low weakening and a secondary low eventually developing off the Virginia coast. Rain will quickly overspread the area from SW to NE through the evening and may fall moderate to occasionally heavy at times. Also, as the precipitation moves in low level temperatures still look to cool enough for some freezing rain to be an issue across the southern Poconos and NW NJ as temperatures aloft will be above freezing. Best chances for ice accretion look to be elevations above 1500 feet or so but amounts should be limited to around a tenth of an inch or less.
By Sunday morning, low pressure will be located near or just east of Cape May as it will be continuing to deepen and move NE driven by a sharp upper level wave becoming negatively tilted. With the slower speed of the system compared to previous forecasts, rain may continue through a good part of the morning for much of the forecast area before finally tapering off west to east through the afternoon as the low finally pulls away. It may also end as some wet snow or a mix of rain/snow over the southern Poconos. Of note, some differences in the models on how quickly low moves away with the GEM being the fastest while the EC is the slowest. Total rain amounts by the time the rain ends look to generally range from around a half an inch north to around an inch near the coast so it shouldn't cause any hydro issues.
Heading into next week, the weather pattern looks to be overall not too active for this region. High pressure moves in Monday and should influence our weather right through Tuesday bringing dry weather and a good deal of sunshine for both days and temperatures returning to more seasonable levels. The next low pressure system looks to affect the area around the middle of next week as it tracks north of the region through the lower Great Lakes towards New England. This will keep us on the warm side of the system so highs Wednesday could be quite mild...possibly around 60 in places. As the system's cold front eventually moves through it may also bring some showers followed by cooler, mainly dry weather for Thanksgiving Day.
Southwest winds have increased to marginal advisory levels early this morning offshore. This is forecast to continue through the early afternoon before a cold front sweeps through and switches winds to west or northwest. At that point, the strongest gusts are expected to occur, including on lower Delaware Bay, where an advisory has been issued beginning at 1 pm. The stronger northwest winds should continue on Delaware Bay through the evening before diminishing (with the advisory expiring at 10 pm), but may take a little longer on the Atlantic waters. Thus, the small craft advisory for the Atlantic waters continues through 6 am Saturday.
A period of showers is expected this afternoon, generally between midday and 6 pm. The strongest gusts may occur with these showers.
Seas are expected to range from 3 to 5 feet through tonight.
Outlook... Saturday...Sub-SCA (Small Craft Advisory) conditions expected.
Saturday night...Conditions nearing SCA (Small Craft Advisory) criteria overnight along with light to moderate rain.
Sunday...SCA (Small Craft Advisory) conditions developing by the afternoon hours with offshore winds gusting around 25-30 kts and waves 3-5 feet. Rain tapering off west to east through the day.
Sunday night through Tuesday...Lingering SCA (Small Craft Advisory) conditions will diminish by daybreak Monday, then sub-SCA (Small Craft Advisory) conditions expected.
NOAA Mount Holly NJ Office: Watches - Warnings - Advisories
PA...None. NJ...None. DE...None. MD...None.
Small Craft Advisory until 6am EST Saturday for ANZ450>455. Small Craft Advisory from 1pm this afternoon to 10pm EST this evening for ANZ431.