Marine Weather and Tide Forecast for Pedrick, NJ

KEY MESSAGES
1. Potential for light icing tonight mainly along and north of I-78 with a light glaze possible along portions of the Garden State Parkway north of I-195.

2. We'll continue to watch a storm system for the late weekend and into early next week.

DISCUSSION
KEY MESSAGE 1...Potential for light icing tonight mainly along and north of I-78 with a light glaze possible along portions of the Garden State Parkway north of I-195.

Winter Weather Advisories have been issued for portions of northeast PA and north New Jersey, mainly along and north of I-78, with the inclusion of Middlesex and Monmouth counties in New Jersey. Freezing rain may result in a light glaze of ice, potentially causing very slippery sidewalks, roads, and bridges.

An upper-level just north of the Great Lakes slides into the Northeast late tonight into Wednesday. A weak surface low (a clipper system) accompanies this trough and tracks to our north. A warm front that lifted across our area this afternoon has boosted warm air advection with a southerly low- level flow.
The forcing for ascent looks to be on the weaker side and focused especially just to our north this evening. As a southwesterly low- level jet on the order of 40-50 knots around 850 mb moves across our region tonight, some enhanced forcing for ascent will be possible as the cold front arrives. This is especially for areas near and north of I-78. The forecast challenge is temperatures, precipitation types and just how much precipitation is realized as it fights off low-level dry air. Warming aloft may support some light snow at the onset that should then go to a bit of sleet then light freezing rain where surface temperatures are at and below freezing. The precipitation intensity looks light and there also looks to be a small window of opportunity for some light icing this evening, again mostly north of I-78, but also including portions of Middlesex and Monmouth counties. Given the snow/ice pack still on the ground across the majority of our area, the low- level cold air may hang on longer especially north and west of the Fall Line. The model forecast soundings become more toward light freezing rain, however weaker forcing and the loss of cloud ice with time could lead to some freezing drizzle prior to the cold front moving through. Any icing looks to be a light glaze (less than 0.10 inches) mostly north of I-78 and especially for the southern Poconos to northwest New Jersey. Some hi-res guidance also shows light accumulations across parts of Middlesex and Monmouth counties in New Jersey as the clipper system shifts ESE across New England, "clipping" our northeastern zones. Outside this region, any precipitation will have to fight through a layer of dry air at the surface. South of I-78 and west of the Garden State Parkway, down to around the I-195 corridor, there is a lower chance for some icing, though it is not zero and very light freezing rain or freezing drizzle may be possible.

Temperatures will drop back below freezing across most of the region this evening, then temperatures may tend to hold steady or rise a little as the low-level jet crosses our area and the warm air advection is maximized prior to the cold front moving through.

KEY MESSAGE 2...We'll continue to watch a storm system for the late weekend and into early next week.

Model guidance continues to depict an area of low pressure affecting the eastern seaboard beginning later Sunday and continuing into Monday. There is some uncertainty in the intensity, track, and timing of this system. That said, it does appear likely there will be at least some precipitation from this system affecting the area late Sunday into early next Monday. And while there is still a lot of uncertainty regarding precipitation types, it is worth noting the airmass in place in advance of this system won't be particularly cold (highs Friday and Saturday in the 30s to low 40s). This would tend to favor more in the way of rain or snow changing to rain near and south of the urban corridor with better chances for more significant accumulating snow occuring farther north over the Poconos into NW NJ. In fact at this time the NBM probabilities for at least 2 inches of snow from this system range from less than 10 percent over southern DE into extreme southern NJ to around 10 to 20 percent near the urban corridor up to around 20-30 percent over the Poconos into NW NJ. These probabilities for the NW most areas are about 10% less than the previous fcst.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Tonight...Prevailing VFR. A brief period of MVFR ceilings and some light freezing rain is possible, mainly at KABE/KRDG/KTTN, where a PROB30 group remains included. Elsewhere, opted to include PROB30 groups for light rain. Light and variable winds this evening, becoming west winds around 5-10 kt after 06Z. A period of low-level wind shear is possible between 00-08Z as a low-level jet surges ahead of a cold front. Moderate-low confidence overall.

Wednesday...VFR. Slight chance of MVFR ceilings in the afternoon with a stratocumulus deck mainly for KRDG/KABE. West-northwest winds around 10-15 kt with gusts up to 20-25 kt. Moderate-high confidence.

Outlook...

Wed night into Thursday... VFR with gusty W to NW winds at times.

Thursday night thru Sunday morning... VFR expected.

Sunday afternoon through Monday evening... sub-VFR possible with rains S/E and snow N/W.

MARINE
The conditions are expected to remain below Small Craft Advisory through tonight. South to southwest winds however will start to increase tonight, then become west-northwest closer to daybreak Wednesday, ramping up to SCA criteria during the daytime hours.

Regarding the river/bay ice...Significant ice cover continues across many area bay waters and inland estuaries. This includes, but is not limited to the Delaware estuary. On rivers, the ice thickness is enough to cause some restrictions in the flow. Per satellite imagery and ice analysis data, the Delaware River is mostly ice covered from the entrance to Delaware Bay northward, or upstream, to at least Washington Crossing.

The most common ways river ice can break up is either through a thermal or mechanical means. We would like to see temperatures rise into the 40s for a few days, which parts of the region are forecast to get to around 40 degrees again on Wednesday afternoon, then again over the weekend and into next week. Significant rainfall, producing river rises, can also break up ice but that is not in the forecast this week.

As a result, ice cover will continue. There may be a pause in the ice growth during the daylight hours as temperatures rise to and above freezing, however temperatures at night will continue to support ice expansion.

Outlook...

SCA conditions are expected to continue Wednesday night and into Thursday before winds and seas subside. Fair weather. Beyond that, conditions will remain below SCA levels thru the weekend and into early next week. Fair Fri/Sat then a chance for rains later Sunday into Monday.

EQUIPMENT
The Fort Dix radar (KDIX) remains out of service. Work remains ongoing with progress obtaining and installing replacement parts. We thank you for your patience.

PHI WATCHES/WARNINGS/ADVISORIES
PA...Winter Weather Advisory until midnight EST tonight for PAZ054- 055-060>062.
NJ...Winter Weather Advisory until 2 AM EST Wednesday for NJZ001- 007-008.
Winter Weather Advisory until 2 AM EST Wednesday for NJZ009- 010-012>014.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 6 AM Wednesday to 6 PM EST Thursday for ANZ430-431-450>455.