Great Egg Inlet to Cape May NJ out 20 NM Marine Forecast
|Tonight...S Winds 5 To 10 Kt. Seas 2 To 3 Ft. E Swell Around 2 Ft At 9 Seconds, Becoming S At 6 Seconds After Midnight.|
|Sat...S Winds Around 10 Kt. Seas 2 To 3 Ft. S Swell 2 To 3 Ft At 3 Seconds.|
|Sat Night...S Winds 5 To 10 Kt, Increasing To 10 To 15 Kt With Gusts Up To 20 Kt After Midnight. Seas 2 To 3 Ft. S Swell 2 To 3 Ft At 3 Seconds.|
|Sun...S Winds 15 To 20 Kt, Increasing To 20 To 25 Kt In The Afternoon. Gusts Up To 35 Kt. Seas 3 To 5 Ft, Building To 5 To 8 Ft In The Afternoon. S Swell 3 To 8 Ft At 5 Seconds. Rain Likely In The Morning, Then Rain In The Afternoon.|
|Sun Night...S Winds 25 To 30 Kt, Becoming Sw After Midnight. Gusts Up To 45 Kt. Seas 8 To 11 Ft. S Swell 6 To 11 Ft At 7 Seconds. Rain. Vsby 1 To 3 Nm After Midnight.|
|Mon...W Winds 25 To 30 Kt With Gusts Up To 45 Kt. Seas 7 To 10 Ft. Se Swell 4 To 8 Ft At 7 Seconds. A Chance Of Rain In The Morning.|
|Mon Night...Nw Winds 20 To 25 Kt, Diminishing To 15 To 20 Kt After Midnight. Seas 4 To 7 Ft. Nw Swell 4 To 5 Ft At 4 Seconds In The Evening.|
|Tue...W Winds 10 To 15 Kt. Seas 3 To 5 Ft.|
|Wed...Nw Winds 10 To 15 Kt. Seas 2 To 4 Ft.|
| Area Forecast Discussion|
National Weather Service Mount Holly NJ
418pm EST Fri Dec 8 2023
The region will feel the influence of surface high pressure to the south through Saturday. A potent cold front approaches Saturday night and Sunday. Potent cold front crosses through Sunday night. High pressure begins to build in Monday and holds a firm grasp over the region to the end of the week.
Near Term - Through Saturday
Quiet weather for the near term. One challenge, for the overnight, will be deciding how much and how dense any fog will be. Overall, a decent setup for radiational cooling, but a dry air mass in place. Decided to continue with the patchy fog wording for the public forecast. Clear to partly cloudy skies otherwise with lows in the low/mid 30s most spots. Light S/SE winds.
A great weather day Saturday with mostly sunny skies and mild temperatures. Highs will reach the low/mid 50s for the areas N/W of the fall-line and upper 50s/low 60s for Delmarva, metro Philadelphia and southern NJ. Mostly South winds 5 to 10 mph.
Short Term - Saturday Night Through Monday
Bottom Line...A potent cold front undergoing significant frontogenesis will cross through the region Sunday night. This will bring a handful of weather impacts to the region Sunday into Monday including strong winds, heavy rain, freshwater and tidal flooding concerns.
Synoptic Pattern...A potent cold front to our west will further approach Saturday night, and look to cross through during the Sunday night period. Following passage, high pressure behind the front will build in Monday as precipitation tapers off.
Saturday night...Winds are forecast to be light for many areas during the first half of the period. With continued moisture and warm air advection during this period, it is possible that fog develops across areas in the region. It is even possible that some marine fog develops early in the period before winds/gusts pick up later on. Forecaster confidence in fog development is low to moderate, so will refrain from discussing visibilities and density of fog for now. In the second half of the period, there are slight chances and chances of precipitation for area.
Sunday...By Sunday morning, the pressure gradient will begin to increase and therefore, a increase in winds and gusts will be felt across the region. Precipitation will likely arrive in our western areas in the morning and will increase in magnitude while spreading eastward with time. By the afternoon, moderate, to heavy rain at times, is expected across the region. Winds will be 15-20 mph sustained with gusts of 30-45 mph possible. Those higher gusts of 40-45 mph will be felt closer to coastal areas.
Sunday night...Heaviest of rainfall is expected to drape eastward with time. Pressure gradient will only increase, with the entire region looking to see 20-30 mph winds with gusts up to 35-45 mph.
Monday...Lingering precipitation behind the cold front will linger some. Our more western areas (primarily Poconos and Sussex County NJ) may see some snow mixed with rain with the cold advection; otherwise, rain is expected for all other areas given the situation. Precipitation chances will taper off with time. No precipitation is expected by the afternoon. Winds and gusts will remain the same magnitude from the previous period, only in the late afternoon/evening will they begin to decrease.
Models indicate mesoscale banding and significant frontogenesis will occur with the system as well as elevated instability. Mesoscale guidance will have be watched going forward. 2.0-3.0 inches of rain are expected with locally higher amounts possible. WPC maintains all of our region in a MARGINAL risk for excessive rainfall with northern NJ in a SLIGHT risk for excessive rainfall (seeHydrology
ction for more details). Strong winds are expected Sunday through Monday as discussed. Wind advisories for the coastal areas is a certainty; high wind watches/warnings are possible for the same areas. High winds will contribute to growing coastal flooding concerns as well as proximity of the event to the new moon on December 12th.
Long Term - Monday Night Through Friday
Latest ensemble and deterministic model guidance indicates the long term will be dominated by surface high pressure. Given almost no divergence among guidance for this situation and the overall synoptic pattern, forecaster confidence in the forecast is high.
Overall, with surface high pressure in control expect a quiet long term weather wise. Precipitation during the term is not expected; no PoPs are included in the forecast. Temperatures will likely run right around normal through the term.
Overall, tranquil weather tonight and Saturday. There could be some fog towards morning. sub-SCA (Small Craft Advisory) winds and seas. Winds mostly South to Southeast around 10 knots.
Outlook... Saturday night...No marine headlines anticipated.
Sunday...Gales with seas building up to 7-9 feet. Gale Watch is in effect.
Sunday night...Gales. Storm force winds possible. Seas 8-12 feet. Gale Watch is in effect.
Monday...Gales continue. Storm force winds possible. Seas around 10 feet will diminish with time to 7-9 feet. Gale Watch is in effect.
Tuesday...SCA (Small Craft Advisory) criteria possible; seas may linger around 5 feet.
Wednesday...No marine headlines expected.
After collaborating with surrounding offices, the MARFC, and WPC, we've decided to issue a Flood Watch late Sunday and through the day on Monday. Yes, we're talking about a 5th and 6th period Watch, but confidence is ramping up that the region will see rainfall between 2 and 3 inches.
Putting things into perspective, this isn't going to be Ida or an event with vast widespread impacts, but it could still be an event that causes a variety of flooding types.
Here's how we see it playing out using the current Quantitative Precipitation Forecast. Poor drainage, urban, small stream, and even isolated flash flooding will commence later on Sunday. It's to our benefit that the ground is nowhere near frozen, but runoff still becomes more efficient this time of year when everything that grows becomes dormant. Runoff will make it to the smaller creeks and streams Sunday night and then to our rivers beginning on Monday. Portions of the mainstem Passaic might not flood until Tuesday.
The mainstem Delaware is not expected to reach Flood Stage at any forecast point. As mentioned, a point or two on the Passaic could flood on Tuesday. The mainstem Raritan is not forecast to flood at this time, although Action Stage is possible. Current simulations do not have any of the mainstem Schuylkill flooding, but with more rain modeled across PA vs. NJ, I would continue to monitor. So outside of our mainstems, we'll need to watch our forecast points across SE PA, and points N and W of the mainstem Passaic. Even places like Minisink Hills and Shoemakers could see good in-bank rises if the 3 inches of rainfall comes to fruition across the southern Poconos.
So with the possibility of poor drainage, urban, small stream, flash, river flooding, and flooding along the back bays (due to poor drainage), we decided to issue a Flood Watch for the entire HSA. We want to get the message out before everyone leaves for the day and goes home to relax a bit this weekend.
NOAA Mount Holly NJ Office: Watches - Warnings - Advisories
PA...Flood Watch from Sunday afternoon through Monday afternoon for PAZ054-055-060>062-070-071-101>106. NJ...Flood Watch from Sunday afternoon through Monday afternoon for NJZ001-007>010-012>027. DE...Flood Watch from Sunday afternoon through Monday afternoon for DEZ001>004. MD...Flood Watch from Sunday afternoon through Monday afternoon for MDZ012-015-019-020.
Gale Watch from Sunday evening through Monday evening for ANZ430-431. Gale Watch from Sunday morning through Monday evening for ANZ450>455.