Marine Weather Net

Cape May NJ to Cape Henlopen DE out 20 nm Marine Forecast


THIS AFTERNOON

W
WINDS
10
KNOTS

TONIGHT

E
WINDS
5 - 10
KNOTS

THU

S
WINDS
5 - 10
KNOTS

THU NIGHT

W
WINDS
20 - 25
KNOTS

The Marine Weather Forecast In Detail:
ANZ454 Forecast Issued: 105 PM EDT Wed Apr 08 2020

GALE WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH FRIDAY EVENING
This Afternoon...W Winds Around 10 Kt, Becoming Ne Late. Seas 2 Ft Or Less. Swell Mainly From The Se With A Dominant Period Of 10 Seconds. Isolated Tstms Late.
Tonight...E Winds 5 To 10 Kt, Becoming S After Midnight. Seas Around 3 Ft Until Early Morning, Then 2 Ft Or Less. Swell Mainly From The S With A Dominant Period Of 8 Seconds.
Thu...S Winds 5 To 10 Kt, Increasing To 15 To 20 Kt With Gusts Up To 30 Kt In The Late Morning And Early Afternoon, Then Becoming W 20 To 25 Kt With Gusts Up To 35 Kt Late. Seas 2 Ft Or Less, Then 3 To 5 Ft In The Late Morning And Afternoon. Swell Mainly From The Se With A Dominant Period Of 9 Seconds. A Chance Of Tstms. Showers Likely In The Late Morning And Afternoon.
Thu Night...W Winds 20 To 25 Kt With Gusts Up To 35 Kt. Seas 3 To 5 Ft. Swell Mainly From The Nw With A Dominant Period Of 5 Seconds. A Chance Of Showers Early In The Evening.
Fri...W Winds 25 To 30 Kt With Gusts Up To 40 Kt. Seas 4 To 6 Ft.
Fri Night...Nw Winds 25 To 30 Kt With Gusts Up To 40 Kt, Diminishing To 20 To 25 Kt After Midnight. Seas 4 To 6 Ft.
Sat...Nw Winds 15 To 20 Kt, Becoming W 10 To 15 Kt In The Afternoon. Gusts Up To 25 Kt. Seas 3 To 4 Ft In The Morning, Then 2 Ft Or Less.
Sat Night...Sw Winds Around 10 Kt. Gusts Up To 20 Kt In The Evening. Seas 2 Ft Or Less.
Sun...S Winds 10 To 15 Kt, Increasing To 15 To 20 Kt With Gusts Up To 25 Kt In The Afternoon. Seas 2 Ft Or Less, Then Around 3 Ft In The Afternoon.
Sun Night...S Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft, Building To 5 To 8 Ft After Midnight. Rain. Winds And Seas Higher In And Near Tstms.
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Area Forecast Discussion
National Weather Service Mount Holly NJ
1026am EDT Wednesday April 8 2020

Synopsis
Showers with embedded thunderstorms will track along a frontal boundary through the overnight hours moving offshore early in the day today. A strong cold front will traverse the region Thursday as low pressure rapidly intensifies over coastal New England and will gradually depart into the maritimes on Friday. High pressure will build in for most of the weekend. Another low pressure coming out of the Gulf Coast states will likely affect the region late Sunday and into Monday.

.NEAR TERM Through Tonight
Showers have departed, and patchy fog continues to burn off with increasing morning sunshine. A rather pleasant day on tap with a surge of warm air spreading into the region. Highs will range from the low to mid 60s in the southern Poconos and far northwest New Jersey to the low to mid 70s in southeast Pennsylvania, most of New Jersey, and Delmarva.

Widespread convective instability will develop across the region, and there is the potential for some isolated thunderstorms to develop. The forcing is weak, however, so any storms that do develop will likely just pulse storms will little forward propagation anticipated.

Short Term - Thursday
An active day of weather is likely Thursday. Synoptically, a classic evolution as a strong shortwave dives into the Great Lakes. The subtropical and polar jets look to phase just south of our region, with a strong (160 kt+) jet max developing. Just downstream the shortwave, surface low pressure will be tracking out of Canada and into New England. Over the course of the day Thursday, the shortwave will begin to pivot more negative in tilt. Meanwhile, the low pressure will find itself in the divergent left exit region of the strong jet max to our south, and will also feel increasing baroclinic influence as it approaches the Gulf of Maine. The result will be a period of rapid deepening of the low on Thursday as its center jumps towards the Maine coast, with its central pressure dropping below 970mb by Thursday evening.

In terms of sensible weather, two primary and somewhat related concerns for Thursday. A strong cold front associated with the strengthening low will move through during the day, likely from late morning through mid afternoon. Ahead of it, there is potential for convection. This is a conditional threat as there is uncertainty as to destabilization. Trends in guidance with the front are generally faster, which would limit daytime heating and instability and help keep convection more limited and/or elevated. However, if we do develop some surface based instability, severe winds would be a concern given very strong forcing and impressive wind profiles. The second concern on Thursday will be the potential for a period of strong synoptic winds immediately behind the front. We should quickly mix out once the front passes, and low level winds remain particularly elevated for a couple of hours. BUFKIT profiles suggest the potential for a period of 40 to 50 mph wind gusts, before winds likely weaken a little, at least temporarily, into the evening and overnight hours. Overnight, strong cold advection will be ongoing, but the breezy conditions will keep the lows near or only a little below average, though it will feel colder.

Long Term - Thursday Night Through Tuesday
Overview... An active pattern is poised to continue over the next several days and likely beyond as persistent troughing over the Great Lakes fuels an active storm track in the East. Definitely a much different type of pattern than we've seen most of the past few months as a steady supply of cold Canadian air gets ushered into the northern US. Combined with a growing supply of very warm, moist air over the Gulf region and a strong subtropical jet, this is a recipe for frequent storminess in the days and potentially couple of weeks ahead. Two synoptic storm systems are likely to impact us this period, one on Thursday and the other early next week, but most of the days this period will feature some weather concerns in one way or another. For this forecast, the bulk of the attention was placed on the Thursday- Friday period, as the weekend appears relatively quiet and the potential storm system early next week is a little too far out to pay much attention especially given concerns in the nearer future.

Dailies... Friday-Friday night... For Friday, attention will again be on the winds as intense low pressure moves out of the Gulf of Maine and into the Canadian maritimes. A tight pressure gradient will be in place, and guidance agrees on deep mixing during the day, likely to near 700mb. Winds at 850mb and above look to be in the 30 to 45 kt range, and much of that is likely to be brought down to the surface in gusts. GFS BUFKIT profiles would support advisory level winds, while the NAM would likely keep us just below. Either way, it will be a windy day and likely on the edge of Wind Advisory thresholds. Boundary layer RH values remain fairly high on Friday, and this will help some surface based instability develop. In the winter months this is the type of day we'd watch for snow squall potential. We're lacking much of a trigger mechanism, but a rain or snow shower is possible Friday especially up north towards the Poconos. Highs on Friday only in the low 50s for most with some 40s to the north as unseasonably cold air is advected in behind Thursday's front. A chilly night is likely as well, but winds should remain elevated enough to prevent a freefall in temperatures and also limit the frost potential.

Saturday - Sunday
. A general lull in active weather for the weekend. High pressure moving out of the Midwest will be centered to our south on Saturday then offshore by Sunday. Could have some fire weather concerns on Saturday pending what the fuel moisture looks like as the winds, while much lighter than Friday, will still be a little breezy and RH values drop a little more. A warming trend is likely over the weekend following the Friday cooldown. Depending on the timing of the next system, could have some showers by Sunday afternoon especially to the south, but think most of the day will be dry.

Sunday night-Tuesday... Our next weather system arrives. As mentioned, did not spend too much time on this period given more pressing shorter term concerns. But the general idea looks to be low pressure lifting out of the Gulf Coast region as a trough ejects out of the Plains and ridging builds along the East Coast. With roots in the Gulf of Mexico, this may be a moisture laden system with potential threats of heavy rain and gusty winds, but we'll have several days to watch its evolution.

Marine
GALE WATCH NOW IN EFFECT FROM THURSDAY AFTERNOON THROUGH FRIDAY EVENING.

Today...Weak low pressure is expected to pass off our coast on this morning, pulling the frontal boundary back to the south.

Wind speeds and wave heigheights are anticipated to remain below the Small Craft Advisory criteria.

Outlook... Wednesday night... Sub-SCA (Small Craft Advisory) conditions expected. Winds northeast shifting to southeast at around 10 kt. Seas 2 to 4 ft.

Thursday-Thursday night... Initially sub-SCA (Small Craft Advisory) conditions. However, a sharp increase in winds is likely during the late morning or early afternoon as winds shift from southwest to northwest with a frontal passage. Gale force winds are anticipated Thursday afternoon. Overnight, conditions will more likely diminish slightly to SCA (Small Craft Advisory) levels, though west-northwest winds could still gust to 30 kt and cannot rule out gale conditions. Seas mainly 3 to 5 ft.

Friday... Westerly gales expected. Wind gusts to 40 kt or slightly higher are likely. Seas 4 to 6 ft.

Friday night-Saturday... Gradual improvement in conditions expected. Winds should drop below gale force early Friday night, and may drop below SCA (Small Craft Advisory) levels on Saturday though will still likely be gusting 20 to 25 kt out of the west-northwest. Seas 3 to 5 ft Friday night diminishing to 2 to 3 ft on Saturday.

Tides / Coastal Flooding
A coastal flood advisory has been issued for the southern shores of the Raritan Bay, the New Jersey shore, and the Delaware Beaches for the high tide cycle on Wednesday evening.

Astronomical high tides will be running high for the next few days associated with the full moon on April 7. We don't have much onshore flow through the next few days, but given the current astronomical high tides, even weak onshore flow could produce minor coastal flooding. At this point, we are expecting spotty minor flooding for most high tide cycles until we get to Wednesday evening. For the Wednesday evening/night high tide, widespread minor flooding is expected for the Atlantic oceanfront.

On the Delaware Bay and tidal portions of the Delaware River, there could be spotty minor tidal flooding for the next few high tide cycles, but the chance for widespread minor flooding is low.

At this point, tidal flooding is not expected along the northeastern Chesapeake Bay.

NOAA Mount Holly NJ Office: Watches - Warnings - Advisories
PA...None. NJ...Coastal Flood Advisory from 7pm this evening to 1am EDT Thursday for NJZ012>014-020-022>027. DE...Coastal Flood Advisory from 7pm this evening to 1am EDT Thursday for DEZ003-004. MD...None. MARINE...Gale Watch from Thursday afternoon through Friday evening for ANZ430-431-450>455.