Marine Weather and Tide Forecast for South River, NJ

NEAR TERM /THROUGH TONIGHT/
A minor update to better define the timing and amounts of clouds which continue to move SE across the CWA A couple upward temperature tweaks across the cloudy areas too. Overall, forecast working out well this morning.

A northwest flow aloft at H5 remain across the area today but it then flattens tonight. High pressure remains across the Southeast states while low pressure, rather deep, moves towards the upper Great Lakes. These factors will promote a warm advection pattern across our area as a warm front crosses southern Canada and adjacent NY state. Cloudiness associated with the front will spill into our northern/western zones today and then decrease tonight. This extra cloudiness will keep today front getting too much warmer than Friday, but high temps a few degrees higher are expected.
Max temps will top out mostly in the mid/upper 30s N/W of I-95 and low 40s for south NJ and Delmarva.

Chances for any precipitation are low today and restricted to the higher elevations for the Poconos and north NJ. P-type will favor light snow with a continuation of below normal temperatures and a rather dry atmosphere in place.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
The pattern changes to a milder one, however that also comes with some precipitation.

As an upper-level trough continues to weaken across the Northeast, a clipper system is forecast to dive southeastward near or just north of the Great Lakes then into New England into Sunday. This will pull a warm front northward across our area, getting north of the area by daytime Sunday. It will turn noticeably milder Sunday as the air mass modifies in the wake of the northbound warm front. Expecting clouds for most of the region to start Sunday before some clearing should work in from the south. This will result in temperatures in the upper 40s/low 50s, with mid 50s further south, where warmer temperatures are expected as skies clear out.

The pattern is active though and therefore the next change is a strong upper-level trough moving across the Midwest and northern Plains Monday. This feature will then work its way slowly south and eastward. A plume of deepening moisture and forcing for ascent results in an expanding area of rain from the Ohio Valley to the Gulf coast states Sunday night. This moisture surge with precipitable water values increasing to around an inch, and ascent arrives in our area on Monday with a period of rain. Rainfall looks to begin after daybreak Monday, with periods of showers through the day. The extent of showers may be weakening with time as the parent low occludes across the upper Great Lakes region, although a weak surface low may develop in our vicinity as an initial weakening front arrives. The overall rainfall amounts with this system look to be on the lighter side especially as the system may be quick moving, however any precipitation is certainly needed across our region.
Amounts generally will be around a tenth to half an inch with the lower totals within that range coming for areas south of Philadelphia, and the higher end coming for areas north of the metro area. Temperatures on Monday should be a little cooler than Sunday given the cloud cover and some rain, though it will not be as cold Monday night.

LONG TERM /TUESDAY THROUGH FRIDAY/
Summary...Milder along with a soaking mid-week rain followed by colder air to end the week.

Synoptic Overview...As an upper-level trough shifts eastward from south-central Canada to the southern Plains Tuesday, surface high pressure remains centered in the western Atlantic. The upper-level trough may be slow to arrive into the East as it potentially amplifies even more. Low pressure tracks north of the Great Lakes Tuesday then toward northern New England during Wednesday. A warm front should be lurking just to our north Tuesday, then a strong cold front moves through later Wednesday. High pressure then starts to build in later Thursday and especially Friday.

For Tuesday...An upper-level trough gradually shifts eastward and closer to the East Coast and this will maintain southerly flow south of a warm front. Low-level warm air advection ahead of an advancing cold front tied to low pressure near or north of the Great Lakes may support some showers, however with our area mainly being within the warm sector may keep a period of rain-free conditions through most of the day. As this system gets closer especially in the late afternoon/early evening into the overnight hours, some forcing for ascent begins to overspread our area from the west and therefore rain chances will increase. Our region will continue to be within a milder regime and therefore no wintry precipitation is expected through Tuesday Night. Temperatures are forecast to be above average, with high temperatures well into the 50s to even some low 60s across the coastal plain and a bit cooler north and west of I-95.

For Wednesday and Thursday...An amplifying upper-level trough slowly arrives from the west along with the passage of a stronger cold front. Our sensible weather will be driven by the timing of the trough and the more organized forcing for ascent into our region. A milder air mass should still be in place Wednesday with high temperatures well into the 50s especially from the I-95 corridor on south and east, with even some 60s possible. A period of rain looks to occur Wednesday ahead of and with the cold front. As the front shifts farther east Wednesday night into Thursday, colder air arrives starts to arrive with temperatures getting back to at or below average on Thursday. Guidance overall showing deep southerly flow with increased moisture ahead of the cold front, and therefore a period of heavier rain is possible. This rain will be beneficial given the ongoing severe to extreme drought. Depending on the timing of the front and developing cold air advection, some snow or rain changing to snow is possible Wednesday night into early Thursday before ending, primarily along and north of I-80. The chance of this occurring looks to be low at this time as some guidance tends to hold to much more moisture back into the cold air with these types of synoptic setups. A west to northwest breeze will also increase during Thursday adding a chill factor.

For Friday...The upper-level trough is forecast to be lifting out of the East with the flow backing more westerly. This results in strong surface high pressure building our area from the southwest with much less wind. High temperatures are forecast to be at or below average.

AVIATION /13Z SATURDAY THROUGH WEDNESDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Today
VFR expected with mid and high level clouds at times. West to Southwest winds increasing to 10 to 15 kts with gusts around 20 kts this morning. Winds will decrease later this afternoon.

Tonight
VFR expected. High clouds with some mid level clouds later tonight. Southwest winds around 5 knots.

Outlook...

Sunday through Sunday Night...VFR. No significant weather.

Monday through Monday Night.. MVFR/IFR conditions expected with periods of rain and low clouds.

Tuesday...Primarily VFR.

Tuesday Night through Wednesday...sub-VFR conditions expected (100%)
with periods of rain.

MARINE
Winds continue to gust above 25 kt on the Atlantic coastal waters, so have extended the Small Craft Advisory out through Noon. On the Delaware Bay, there are gusts near 25 kt, but for the most part any gusts above 25 kt are coming from observation sites where the wind measuring equipment is elevated. After that, winds and seas will remain below SCA levels until later tonight when winds and seas will again build back to SCA levels.
Fair weather today and tonight.

Outlook...

Sunday...A Small Craft Advisory is in effect through 3 PM Sunday for the ocean waters as gusts out of the west/southwest around 25-30 kt are expected with seas nearing 5 feet. No marine headlines on the bay.

Monday through Tuesday...No marine headlines expected. Periods of rain expected on Monday.

Tuesday Night...SCA conditions possible late (40-50%) as gusts approach 25 kt.

Wednesday...SCA conditions expected (100%) with 25-30 kt wind gusts and 5 to 7 foot seas.

Wednesday Night...SCA conditions expected (100%) with gales possible (40-50%).

PHI WATCHES/WARNINGS/ADVISORIES
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until noon EST today for ANZ450>455.