Marine Weather Net

Delaware Bay south of East Point NJ to Slaughter Beach DE Marine Forecast


10 - 15


5 - 10


15 - 20


15 - 20

The Marine Weather Forecast In Detail:
ANZ431 Forecast Issued: 921 PM EST Fri Jan 17 2020

Overnight...N Winds 10 To 15 Kt, Becoming Ne 5 To 10 Kt. Waves 3 To 4 Ft Late This Evening And Early Morning, Then 2 Ft Or Less.
Sat...Se Winds 5 To 10 Kt, Becoming S 15 To 20 Kt With Gusts Up To 25 Kt. Waves 2 Ft Or Less, Then 3 To 4 Ft Early In The Afternoon. Snow Or Rain Likely In The Late Morning And Early Afternoon. Rain Late. Vsby 1 To 3 Nm In The Late Morning And Early Afternoon.
Sat Night...Sw Winds 15 To 20 Kt. Gusts Up To 25 Kt. Waves 3 To 4 Ft. Rain Early In The Evening, Then A Chance Of Rain Late In The Evening.
Sun...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Waves 3 To 4 Ft.
Sun Night...Nw Winds 20 To 25 Kt With Gusts Up To 30 Kt. Waves 3 To 4 Ft.
Mon...N Winds 15 To 20 Kt With Gusts Up To 25 Kt. Waves 3 To 4 Ft.
Mon Night...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Waves Around 3 Ft.
Tue...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Waves Around 3 Ft.
Tue Night...N Winds 10 To 15 Kt. Gusts Up To 20 Kt In The Evening. Waves Around 3 Ft.
Wed...N Winds 5 To 10 Kt. Waves 2 Ft Or Less.
Wed Night...N Winds Around 5 Kt. Waves 2 Ft Or Less.
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Area Forecast Discussion
National Weather Service Mount Holly NJ
938pm EST Fri Jan 17 2020

High pressure will move offshore through the overnight hours into Saturday morning as a developing area of low pressure moves across the Great Lakes and into the Northeast through Sunday morning, dragging a cold front across the region as it does so. A broad surface high will build across the eastern U.S. into next week, ushering in colder, more seasonable temperatures.

Near Term - Until 6am Saturday Morning
930pm Update: Adjusted low temperatures down quite a bit for the overnight period. Radiational cooling will allow temps to drop quickly as winds continue to diminish tonight.

Previous discussion... High pressure will continue to move across the Northeast, moving offshore overnight. Winds will continue to subside overnight as the pressure gradient lessens its grip. Clear skies will prevail through the evening and into the early portion of the overnight, before high clouds begin to work their way into the region ahead of the highly-advertised winter storm after midnight. Given the cold air advection and radiational cooling potential tonight, lows will be quite cold compared with what we've seen thus far this winter. Expect most places to dip down into the teens. Dew points will also continue to lower and dry air continues to work its way southward as the continental polar airmass works its way southward out of Canada into Saturday. These two facets will be issues of conflict that will throw added complexity into the forecast for the upcoming winter storm.

.SHORT TERM /6am SATURDAY MORNING THROUGH SUNDAY/... 930pm Update: Adjusted Probability of Precipitation to match the latest hi-res guidance in the evolution of precipitation across the forecast area during Saturday's wintry weather extravaganza. This was mainly to pinpoint the leading band of precipitation late tomorrow morning ahead of the main round later in the afternoon and evening. In other words, there will be a lull in precipitation early in the afternoon.

I suspect we may actually see quite a bit of sleet with this event as the snow to rain transition begins, as depicted by the NAM which has historically handled these overrunning snow-to- rain events quite well. Warm air advection will be stout just above the surface, however the exceptionally cold, dry air in place ahead of the system usually remained deeply entrenched and sticks around longer than expected. If we do see a lot more sleet, this will drastically reduce snow totals but would have similar impacts to travel. I made some minor adjustments to the Storm Total Snow forecast, mainly to better capture the morning band of precipitation as mentioned earlier. No changes to the headlines (Winter Weather Advisory) at this time.

This system is indeed a tricky one.

Previous discussion... A fairly potent trough will continue to works its way across the Midwest into the eastern U.S. Snow will overspread the region Saturday morning as an initial batch of precipitation pushes east into the region. This initial round looks to fall as mostly snow starting around 8 to 10 am from west to east, especially across SE PA and North and Central NJ. Given the very dry air/low dew points and radiationally-cooled air that will meet this precipitation, this will likely be a quick-accumulating snowfall once it does start. Road temperatures will likely support some accumulation across much of the region.

After the initial round of snow makes its way across the region, there looks to be somewhat of a lull for an hour or two before the more steady round of precipitation moves eastward. With this, the warm nose will begin to work northward, leading to a upward progression in surface temperatures. Most locations are forecast to rise to or above freezing except the very highest elevations across extreme NW NJ and the Pocono Plateau. Forecast soundings still support a changeover to sleet, with less of a chance for freezing rain all in all. Expect a changeover to all rain for much of the region outside of the Poconos and northwestern NJ, where precipitation may stay all snow or a mixture of snow and sleet. Of course, snow amounts continue to remain a tricky item of interest owing to the precipitation type transition (and increasingly marginal surface temperatures), though guidance has been pretty consistent on the overall trend and track of the parent low from the Great Lakes across New England. The cold dry air ahead the system will be one the wrenches in the forecast. The NAM seems to be a little bullish on the progression and advection of the warm nose, taking it through much of SE PA compared to the ECMWF (European Centre for Medium-Range Weather Forecasts) and GFS, so tried to take a blended approach regarding the transition timing.

Some changes occurred for the storm total snowfall amounts with an upgrade to a Winter Weather Advisory for the northern portions of the I-95 Corridor from Trenton northwest. Also added Western Chester and lower Bucks Counties in SE PA to the advisory given the final storm total map. Amounts at or under an inch seem to be the most likely outcome in these areas (with mostly a rain event southeast of a Stevensville to Atlantic City line). Current forecast has 1-2 inches generally for the western suburbs of Philadelphia toward the Trenton area, with 2-5 inch totals along and north of a Reading to Staten Island line (highest amounts being in the Poconos and northwestern NJ). Confidence in snow amounts is always on the low side when precipitation type issues combine with marginal and warming low-level temperature profiles.

Conditions dry out Sunday as the low lifts out of the region with northwest flow developing in its wake. The increasing pressure gradient will lead to another windy day, though not as bad as Thursday. Wind gusts look to range from 20 to 30 mph, with the potential for a few gust to 40 mph at times, especially along and near the coast. There may also be a few snow showers or squalls as a weak cold front reinforces the penetrating colder air in the afternoon. Confidence was not high enough to include this in the forecast yet, but it will be something to watch.

Long Term - Sunday Night Through Friday
A few snow showers/flurries will be possible into Sunday evening, mainly over our far northern zones through the southern Poconos and NW NJ as a reinforcing front moves through ushering in colder air. It will also remain breezy due to the gradient between low pressure moving through Atlantic Canada and high pressure nosing south into the central CONUS.

Heading into the Monday through Friday period of next week, conditions look to be dry and generally cold as a large area of high pressure drifts east across the eastern U.S. As a result, expect plenty of sunshine each day. NW winds will remain a bit breezy Monday but diminish through mid week as the high moves east overhead. Temperatures through the first half of the week will be seasonably cold but will moderate through the mid to late week period as the high moves through then drifts east off the coast.

Tonight...SCA (Small Craft Advisory) conditions have diminished and winds and seas will continue to diminish overnight.

Saturday...Light and variable winds will quickly turn southerly increasing to advisory level during the afternoon with the potential for gusts to near gale force by Saturday night. Seas building from 2 to 4 feet Saturday morning to 4 to 7 feet into Saturday night.

Sunday...Westerly winds with advisory-level wind gusts by Sunday afternoon. Seas from 4 to 6 feet.

Outlook... Sunday night...Lingering advisory conditions expected as northwest winds slowly diminish.

Monday...Advisory level winds possible into Monday morning with winds continuing to diminish though and likely below advisory levels in the afternoon.

Monday night through Wednesday...Generally sub-advisory winds/seas expected through this period.

NOAA Mount Holly NJ Office: Watches - Warnings - Advisories
PA...Winter Weather Advisory from 10am Saturday to 1am EST Sunday for PAZ054-055-060>062-101-103-105-106. NJ...Winter Weather Advisory from 10am Saturday to 1am EST Sunday for NJZ001-007>010-012-015. DE...None. MD...None. MARINE...None.