Cape Henlopen to Fenwick Island DE out 20 nm Marine Forecast
|Tonight...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 3 To 4 Ft. Areas Of Dense Fog This Evening, Then Areas Of Fog After Midnight. Vsby 1 Nm Or Less. Swell Mainly From The S With A Dominant Period Of 5 Seconds.|
|Sat...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 3 To 4 Ft. Areas Of Fog Early In The Morning. Areas Of Fog In The Afternoon. Vsby 1 Nm Or Less Early In The Morning, Then 1 To 3 Nm In The Afternoon. Swell Mainly From The S With A Dominant Period Of 6 Seconds.|
|Sat Night...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas Around 3 Ft. Areas Of Fog Early In The Evening With Vsby 1 To 3 Nm. Swell Mainly From The S With A Dominant Period Of 5 Seconds.|
|Sun...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas Around 3 Ft. Swell Mainly From The S With A Dominant Period Of 5 Seconds.|
|Sun Night...S Winds 10 To 15 Kt, Becoming W After Midnight. Gusts Up To 20 Kt. Seas Around 3 Ft. A Chance Of Tstms.|
|Mon...N Winds 5 To 10 Kt. Gusts Up To 20 Kt In The Morning. Seas 3 To 4 Ft. A Chance Of Showers.|
|Mon Night...Ne Winds 5 To 10 Kt, Increasing To 10 To 15 Kt After Midnight. Seas Around 3 Ft. A Chance Of Showers.|
|Tue...Ne Winds 10 To 15 Kt. Seas 3 To 4 Ft. A Chance Of Showers.|
|Tue Night...E Winds 10 To 15 Kt. Seas 3 To 4 Ft. A Chance Of Showers In The Evening.|
|Wed...E Winds Around 10 Kt. Seas 3 To 4 Ft.|
|Wed Night...S Winds Around 10 Kt. Seas 3 To 4 Ft. Winds And Seas Higher In And Near Tstms.|
| Area Forecast Discussion|
National Weather Service Mount Holly NJ
438pm EDT Fri May 20 2022
A mid level disturbance will move across the area this evening. A Bermuda high pressure pattern will develop for Saturday and Sunday with the Mid Atlantic region on the northwestern periphery of the high. A strong cold front will move through Sunday night as low pressure passes to our northwest, with the front slowly settling offshore on Monday. High pressure builds in for Tuesday and Wednesday, then a frontal system may approach the area later next week.
Near Term - Until 6am Saturday Morning
A mesoscale convective vortex was passing over our region late this afternoon. Showers and thunderstorms developed ahead of the feature and will continue to move across eastern Pennsylvania, and central and northern New Jersey into this evening.
We have been able to cancel the Tornado Watch for areas to the west and south of Philadelphia based on radar trends. The watch remains in effect for Bucks County, Pennsylvania, and for parts of central and northern New Jersey until 7:00 PM.
The CAPE values are lower in central and northern New Jersey than they were in areas to the west and southwest. However, the thunderstorms have some momentum as they advect into those areas. There continues to be a decent amount of shear and the storms were rather organized. We have been receiving numerous reports of hail will localized strong wind gusts.
The precipitation will remain to the north of much of eastern Maryland, Delaware and far southern New Jersey.
The mid level short wave trough associated with the convection is forecast to pass overhead this evening and off the coast by about 10:00 PM, bringing and end to any lingering showers in our region. High clouds are expected to linger overnight.
A fog bank developed over the coastal waters of New Jersey and Delaware today. It may expand inland tonight. A warm front is anticipated to lift northward through our region late tonight and it may cause some of the fog over land to dissipate toward daybreak.
A south to southeast wind 10 to 15 MPH into this evening is forecast to become light and variable tonight. Low temperatures are expected to be in the 60s and lower 70s with muggy conditions.
Short Term - 6am Saturday Morning Through Sunday Night
The warm front will move well north of the area during the day Saturday, while a thermal trough will develop across the east coast by the afternoon. Saturday is still forecast to be very hot across the area with high temperatures in the mid to upper 90s for most areas. Heat index values will likely reach around 100 degrees for portions of southeast Pennsylvania, central and southern New Jersey, as well as Delaware and eastern Maryland. The Heat Advisory remains in place where it was previously as these areas have the lower heat index criteria of 100 degrees, while areas south of the advisory have criteria of 105, and we are not expected to reach that high there. For areas north and west of the advisory, temperatures may end up being a few degrees lower than in the advisory and southward as they will be north and west of the developing surface thermal trough and thicknesses will be slightly lower farther north and west. Nevertheless, it will still be a hot day!
Saturday and Saturday night should remain dry as any showers/thunderstorms should develop to our west, west of the thermal trough and closer to a passing short wave/vorticity impulse aloft. Saturday night will be a muggy night as temperatures may not drop below 70s for some areas, and barely into the 60s for most other places.
Sunday will likely be another hot day, although not at hot as Saturday as thicknesses lower some across the area. Plus there will likely be some cloud cover ahead of an approaching cold front which could limit how high temperatures get.
The cold front will approach the area Sunday afternoon, but likely not get here until Sunday evening. The timing of the front could play into how many thunderstorms we get, and how strong their potential will be. Guidance continues to indicate showers and scattered showers developing late in the afternoon into the evening as the cold front moves through, before diminishing as the front moves eastward. Instability is increases as CAPE values could reach 1000-2000 J/kg, while shear is not very strong, only 20-30 knots due to weak mid level flow, DCAPE values of 600-700 J/kg could lead to a some isolated damaging wind gusts.
As the front moves offshore overnight, any precipitation will end overnight and cooler/drier air will move in overnight. Winds could become occasionally gusty overnight as well.
Long Term - Monday Through Friday
A much cooler pattern relative to the weekend heat develops for next week. Synoptically, following the Sunday night cold frontal passage, the upper level pattern does not change dramatically, with considerable positive height anomalies remaining in place over the East. However, an expansive surface high pressure center will build from the Great Lakes into northern New England from Monday through midweek. This will act to turn the winds northerly, then easterly, drawing cooler air into the region despite the warmer look to the upper air pattern. High temperatures into the 70s will be common for much of next week, and "cooler coast" will be a common theme as well.
Regarding rain chances, the week does not appear too rainy overall. NBM Probability of Precipitation in the Monday through Wednesday range generally depict 30% or less. This is agreeable based on latest guidance and the synoptic pattern of strong high pressure to the north. While this still leaves some mentions of showers, expect most if not all of the first half of the week to be dry. Better rain chances should arrive later in the week as a frontal system approaches in response to a slow moving trough pushing into the Great Lakes.
Dailies... Monday-Monday night... Most indications are that the cold front should be offshore by Monday morning. However, it will be slowing down as it moves through, and there is still a chance it comes to a near stall over the coast or just offshore. As such, there is a slight chance to chance for some residual showers especially over the southern half of the area, and a good deal of cloud cover may linger through the day. But by and large, the story will be the more seasonable temperatures, with daytime highs in the 70s and overnight lows in the 50s.
Tuesday-Wednesday... Some additional cooling is expected into midweek as high pressure centers itself to our north and turns the winds onshore. High temperatures look to favor the low 70s on these days, but only in the 60s closer to the coast. Do have a slgt chance of showers for most of the area with chance showers further south mentioned Tuesday. However, given the strong high pressure to the north, a fully dry day Tuesday remains possible. On Wednesday, Probability of Precipitation increase a little more to the north as a frontal system possibly begins to approach from the southwest. But am still not too enthused on rain chances Wednesday either, and have a feeling that day will probably be dry as well.
Thursday And Friday
By Thursday, a frontal system appears likely to approach the area as a slow moving trough, and possibly a closed low, track towards the Great Lakes. While confidence in details remains low, the overall pattern should support an increase in rain potential by the latter half of next week. Temperatures should start to recover also by Thursday as a southwest flow develops, and we may get back to around 80 in some places both Thursday and Friday.
A southeast to south wind 10 to 20 knots is forecast to become southwest 10 to 15 knots late tonight. Waves on our ocean waters will likely stay in the 2 to 3 foot range, with waves on Delaware Bay remaining at 2 feet or less.
A fog deck over our coastal waters is expected to remain there for much of the night. We have a Dense Fog Advisory in effect until 10:00pm this evening. We will keep an eye on the trends this evening and we may need to extend the advisory at least overnight.
The shower and thunderstorm activity into this evening is expected to remain mostly north of Barnegat Inlet, New Jersey.
Outlook... Saturday - Sunday
ight...Winds and waves mostly remain below advisory levels through the period. However, winds could approach advisory levels for a brief period Saturday afternoon/evening, and again Sunday afternoon/evening. Wind will be south to southwest Saturday through Sunday, shifting to north behind the cold front.
Monday - Wednesday
No marine headlines are currently anticipated. Offshore winds early on Monday, becoming onshore later Monday into Tuesday and through midweek. Seas of 2 to 4 feet generally expected.
A hot and humid air mass is forecast to overspread the region this weekend. The hottest day will be Saturday. Here is a list of the high temperature records for Saturday and the record high temperatures for the month of May.
Locations 5/21 Record High Temps May Record High Temps --------- ---------------------- ---------------------
Philadelphia, PA 95 in 1934 97 in 1991 Reading, PA 96 in 1996 96 in 1996/ 1962 Allentown, PA 92 in 1934 97 in 1962 Mount Pocono, PA 87 in 1911 94 in 1911 Trenton, NJ 94 in 1934 99 in 1986/ 1911 Atlantic City (airport), NJ 93 in 1996 99 in 1969 Atlantic City (marina), NJ 85 in 1934 95 in 1925/ 1895 Wilmington, DE 95 in 1996 98 in 1895 Georgetown, DE 94 in 1996 98 in 1991
NOAA Mount Holly NJ Office: Watches - Warnings - Advisories
Heat Advisory from 11am to 10pm EDT Saturday for PAZ070-071- 101>106. NJ...
Heat Advisory from 11am to 10pm EDT Saturday for NJZ008>010- 012-013-015-017>020-027. DE...
Heat Advisory from 11am to 10pm EDT Saturday for DEZ001. MD...None.
Dense Fog Advisory until 10pm EDT this evening for ANZ431- 450>455.