Marine Weather Net

Cape Henlopen to Fenwick Island DE out 20 nm Marine Forecast


10 - 15


10 - 15


5 - 10


10 - 15

The Marine Weather Forecast In Detail:
ANZ455 Forecast Issued: 703 PM EDT Tue Jun 22 2021

Tonight...N Winds 10 To 15 Kt, Becoming Nw 15 To 20 Kt. Gusts Up To 25 Kt. Seas 3 To 5 Ft. Showers Likely Early This Evening. Swell Mainly From The S With A Dominant Period Of 7 Seconds.
Wed...N Winds 10 To 15 Kt, Becoming Ne 5 To 10 Kt Late. Seas Around 3 Ft. Swell Mainly From The E With A Dominant Period Of 7 Seconds.
Wed Night...E Winds 5 To 10 Kt. Seas Around 3 Ft In The Evening, Then 2 Ft Or Less. Swell Mainly From The Se With A Dominant Period Of 7 Seconds.
Thu...E Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 3 To 4 Ft. Swell Mainly From The E With A Dominant Period Of 5 Seconds.
Thu Night...E Winds 10 To 15 Kt. Gusts Up To 20 Kt In The Evening. Seas 3 To 4 Ft.
Fri...E Winds 5 To 10 Kt. Seas Around 3 Ft.
Fri Night...S Winds Around 10 Kt. Seas Around 3 Ft.
Sat...S Winds Around 10 Kt, Increasing To Around 15 Kt In The Afternoon. Seas Around 3 Ft.
Sat Night...S Winds Around 15 Kt. Seas 3 To 4 Ft.
Sun...S Winds 10 To 15 Kt. Seas 3 To 4 Ft.
Sun Night...S Winds 10 To 15 Kt. Seas 3 To 4 Ft.
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Area Forecast Discussion
National Weather Service Mount Holly NJ
358pm EDT Tuesday Jun 22 2021

A cold front will continue moving offshore tonight. High pressure then builds in for Wednesday and Thursday before moving offshore. A slow moving frontal boundary will cross the Great Lakes region from this weekend into early next week. The mid-Atlantic will then be in between the front to the west and offshore high pressure for several days.

Near Term - Through Wednesday
Tonight: The front and upper air features that affected the weather much of Tuesday will be offshore by evening with only some lingering clouds and a few scattered showers before sunset. After that, drier and cooler air will continue to overspread the area. Mostly clear skies will be over the region tonight. Some patchy fog is possible, but it is not expected to become too widespread of dense with the drier air arriving. Lows will be chilly for late June with readings in the 40s in many areas with some low 50s across Delmarva and metro Philadelphia. Winds will be from the north or northwest settling to under 5 mph.

Wednesday: High pressure will build across the area with plenty of great weather. Sunny skies and cool temperatures are expected. Highs will top out in the upper 60s to low 70s for the NW areas and mid 70s for Philadelphia and much of Delmarva. Winds will be from the northwest around 10 mph early then becoming light and variable late.

Short Term - Wednesday Night Through Thursday Night
Mainly tranquil weather is expected this period. We remain in a post- frontal air mass by Wednesday night with surface high pressure overhead. Clear, calm, and rather cool conditions are expected with lows dropping well down into the 50s in most areas. Another mostly sunny and pleasant day is expected Thursday. High pressure will shift off to the north and turn our flow onshore. This will keep highs only in the upper 70s to near 80 despite some height rises aloft, and a little cooler at the coast with the easterly breeze. For Thursday night, most model guidance is indicating the development of a weak surface low pressure off the Outer Banks, likely along the remains of an offshore cold front, and moving in the general direction of the New Jersey coast. This could potentially bring some light showers to eastern and southeastern areas by later Thursday night, where slgt chance Probability of Precipitation was added. But overall, should be a mostly dry and quiet night with lows a few degrees warmer than the prior night.

Long Term - Friday Through Tuesday
Overview... A typical summer pattern develops for the long term as a Bermuda High becomes established offshore and a slow moving trough develops over the Great Lakes. This is a classic southwest flow regime which is likely to be in place for at least several days beginning the end of this week and heading into next week. The result will be a transition from the dry and cooler weather during the middle of this week to a sustained warm and humid pattern, especially by the time we get to the weekend. From Saturday onward, we will mostly be looking at highs in the mid 80s to near 90. This is nothing atypical for the season, but combined with the increasing humidity, we may flirt with Heat Advisory levels at times during the period. Rain chances in this pattern are quite uncertain at the moment. It will depend heavily on how fast a cold front to the west approaches as Great Lakes troughing slowly moves eastward and/or starts to lift out. Model guidance has a spread of several days on when this front will move through, or if it even will at all as opposed to just washing out. My general thinking is that rain chances will gradually increase from Saturday onward, especially to the west, but that overall there will be a lot of dry hours through the period.

Dailies... Friday-Friday night... The weak wave of low pressure mentioned for Thursday night will likely still be in the vicinity on Friday. Have added some slgt chance Probability of Precipitation to southeastern areas for the daytime Friday. With rising heigheights aloft and a lack of any dynamic support, this surface low should remain very weak, and any shower activity should be limited. Otherwise, as the flow turns more southerly combined with the height rises, we should warm up a bit on Friday, with highs rising into the low 80s in most areas. By overnight, dry weather is expected, but it will be a warmer and stuffier night as humidity continues to increase.

Saturday - Sunday
. We enter the southwest flow regime in earnest over the weekend. Highs of 85 to 90 combined with dew points near 70 will yield heat index values of 90 to 95 degrees on both days, with Sunday being a little warmer than Saturday. As alluded to above, rain chances will heavily depend on the progress of a cold front to our west. Am inclined to think the weekend will be mostly dry due to the lack of forcing and weak shear. Probability of Precipitation range from slgt chance to chc, with the highest values to the west (closer to the front) and Probability of Precipitation values on Sunday higher than on Saturday since the front should be a bit closer. Coastal areas will see slightly cooler temperatures and should have the lowest shower/storm chances, so current indications are for a good weekend at the beaches.

Monday-Tuesday... Continued warm and humid weather is expected with similar temperatures to over the weekend. The cold front should continue to crawill eastward, and as a result my inclination is that shower and storm chances should generally be higher for these days than over the weekend. But much remains to be determined owing to uncertainty over the timing of the front.

Tonight: We will raise a SCA (Small Craft Advisory) flag with the strengthening pressure gradient between the building high and departing front. Some of the high res. guidance shows another wind surge possibly moving down Delaware Bay later this evening, so even if winds decrease a bit around sunset, they may freshen up for the early overnight period. Gusts around 25 knots expected and seas up to 5 ft on the ocean and 2 to 4 ft for Delaware Bay this evening. Showers and tstms for the evening then improving weather.

Tuesday: sub-SCA (Small Craft Advisory) conditions expected as high pressure crests over the waters by late afternoon. NW winds 10 to 15 knots during the morning then decreasing by afternoon.

Outlook... Wednesday night-Sunday... No marine headlines are anticipated. A couple of wind shifts through the period but gusts mostly 20 kt or less. Mainly dry weather expected. Seas 2 to 4 ft.

Rip Currents... Increased southerly winds and waves of 4 to 5 feet, coupled with an underlying long period swell (related to Claudette) will result in a moderate risk for the formation of dangerous rip currents today and Wednesday. Although the long period swell is not expected to become the dominant swell, and winds should shift to an off shore northwesterly direction later this morning and afternoon.

NOAA Mount Holly NJ Office: Watches - Warnings - Advisories
PA...None. NJ...None. DE...None. MD...None.
Small Craft Advisory until 6am EDT Wednesday for ANZ450>455. Small Craft Advisory until midnight EDT tonight for ANZ430-431.