Marine Weather and Tide Forecast for Lake Como, NJ

NEAR TERM /THROUGH TONIGHT/
There are two wet weather systems this week, today will feature the weaker of the two with increasing clouds this morning followed by a 3 to 5 hour period of rain for the region. A quick moving upper short wave and weak surface low/front will navigate thru the northern Middle Atlantic area. Total rainfall will range from around a tenth of an inch for south NJ and Delmarva to a third of an inch (or so) up north across Sussex County NJ and for the Lehigh Valley and southern Poconos. The rains will be mostly late morning into the afternoon.

The clouds and rains will keep temperatures closer to normal (compared to Sunday), readings will still be mild across the eastern areas where some warm air advection will take place prior to the rains. Highs across ern NJ and Delmarva will be in the low 50s while N/W areas will see max temps in the mid/upper 40s.

Once the rains end by this evening, skies will remain cloudy overnight and areas of fog are possible too. There will not be much in the way of stronger winds or dry air to promote improving conditions. The clouds will keep temps mild tonight with overnight lows mostly in the upper 30s to low 40s.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
As we go through the day Tuesday, a rather deep upper-level trough gradually shifts eastward and closer to the East Coast, maintaining 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 most of the day should be dry with lingering cloud cover. 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 Tuesday night through Wednesday night, an trough upper-level trough moves into the East during this time frame along with the passage of a strong cold front. Some even warmer air is forecast to advect into our area with this more pronounced from about the I-95 corridor on south and eastward. Strengthening southerly flow will result in temperatures actually rising overnight Tuesday night for many places. High temperatures are forecast to be well into the low to mid 60s on Wednesday ahead of the strong cold front. Rain will develop Tuesday night and become widespread and continue for most if not all of of Wednesday.

Some guidance continues to hint at some weak elevated instability developing ahead of the front, which could result in a few rumbles of thunder, especially over the southern half of the area. A robust shortwave rounding the base of the trough looks to result in the trough taking on a negative tilt for a time. If this occurs, a zone of stronger forcing for ascent could develop especially with the cold front which would result in a narrow line of heavier showers/rain embedded within the rain shield. This will need to be watched given the strength of the wind field and shear that is forecast, although lapse rates look to be on the weak side and therefore resulting in a rather limited severe weather risk.
Precipitable water values may get as high as 1.50 inches ahead of the front which is nearing the climatological maximum for mid- December, making heavier rain rates look likely especially Wednesday afternoon with the front coming through. Rain may also be enhanced some by a weak surface low that develops along the front as it is crossing our area. The rain will be beneficial though given the ongoing severe to extreme drought. As of now, 2 to 3 inches of rain is forecast across the region Tuesday afternoon through early Wednesday night. A Marginal Risk (1/4)
is in place for Wednesday, which is about right given how dry it has been. More information can be found below in the Hydrology section.

As the front shifts toward and off the coast later Wednesday, a quick increase in the cold air advection will bring in much colder air. Guidance has trended later with the frontal passage and incoming cold air advection. Given how quickly precipitation will shut off on Wednesday night, this will result in a lower risk for any accumulating snowfall, though a few tenths of accumulation are possible for the Poconos and northern Lehigh Valley. Temperatures are forecast to drop below freezing everywhere by daybreak Thursday.
A westerly breeze Wednesday night will help to dry the surfaces as much drier air advections in and dew points crash behind the front.

LONG TERM /THURSDAY THROUGH SUNDAY/
Summary...Much colder to end the week, then some warming over the the weekend.

Synoptic Overview...As the influence of the upper-level trough becomes removed from our area through Thursday night, some ridging aloft arrives. This will support surface high pressure building in later Thursday and especially Friday into Saturday, before becoming more centered to our northeast during Saturday into Sunday.

For Thursday...A strong upper-level trough across most of eastern Canada and extending down across the Great Lakes, Northeast and Mid- Atlantic regions will gradually lift northeastward through Thursday night. As deepening low pressure moves toward the Canadian Maritimes, strong high pressure is forecast to be building into the Ohio Valley and lower Mid-Atlantic. This will provide for a tightened pressure gradient across our region, with a gusty west to northwest wind, with gusts generally around 20-30 MPH possible. It will be much colder given strong cold air advection along with a much drier air mass which is forecast to settle in. Highs will only top out in the mid to upper 30s, with some low 40s over lower Delmarva, though the gusty breeze will make it feel colder. There will be cyclonic flow aloft in place and with just enough moisture lingering, areas of stratocumulus may be in place, mainly over the Lehigh Valley and Poconos, for a time before clearing out at night.
Strong high pressure builds closer at night and therefore the winds should diminish quickly. Lows on Thursday Night will generally be in the upper teens.

For Friday and Saturday...The upper-level trough is forecast to lift farther away from our area Friday with even some mid level ridging arriving Friday night into Saturday. This will support strong surface high pressure building right over our area Friday with much less wind but still cold air in place. The next upper-level trough looks to be sliding across the Midwest to central Plains into Saturday, with surface high pressure starting to become more centered to our northeast. A warm front may organize and lift into the eastern Great Lakes Friday night into Saturday, with some warm air advection starting to get into our area. As a result, after much below high temperatures Friday (generally low to mid 30s), the high temperatures on Saturday will be higher but still looking to be mainly below average.

For Sunday...A cold air damming setup may be in place as strong high pressure is centered up across New England but is wedged down through the Mid-Atlantic. As this occurs, a shortwave trough sliding eastward across the Ohio Valley region will induced some warm air advection aloft and this will increase the clouds. In addition, a coastal front may develop from the Mid-Atlantic down toward Florida and this coupled with the approaching upper-level trough from the west may start to bring in some added moisture toward or into parts of our area. The timing and details are much less certain and therefore opted to keep PoPs on the lower side especially given the initially very dry air in place along with high pressure forecast to be extending across our area from the northeast.

AVIATION /09Z MONDAY THROUGH FRIDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Today... Fair/VFR early, then lowering CIGs with the arrival of rains by mid/late morning which will continue into the afternoon.
MVFR then IFR most areas with LIFR possible late. Light E/SE winds will switch around to S/SW during the afternoon. Medium confid overall.

Tonight
Rains will have ended by early evening, but only slow improvement in CIGS/VSBYs for the terminals with IFR mostly but LIFR vsbys with fog possible. Light SW/W winds. Low/medium confid at best.

Outlook...

Tuesday.. MVFR conditions possible with low ceilings and reduced visibility in any showers.

Tuesday Night through Wednesday.. MVFR/IFR conditions expected with periods of heavy rain and low clouds. Southerly wind gusts 20-25 kt possible during the day on Wedensday.

Wednesday Night.. MVFR/IFR conditions early but skies clear out for the second half of the night and a return to VFR is likely. Westerly wind gusts around 20-25 kt possible.

Thursday...VFR. Gusty west/northwest winds around 20 to 30 kt.

Thursday Night through Friday...VFR. No significant weather.

MARINE
Winds and seas increase today with low-end SCA conditions possible by afternoon for the ocean waters. Overall, better chances for SCAs across the southern waters, so we'll keep the flag 'as is' attm with no flag adjacent to OKXs waters. Gusts to 25 kts and seas building around 5ft into the evening. SCA will expire around midnight. Rain for a 3 to 5 hour period this afternoon and ending by early this evening. Areas of fog expected.

Outlook...

Tuesday...No marine headlines expected.

Tuesday Night...SCA conditions likely late in the night as wind gusts approach 25 kt and seas build toward 5 feet.

Wednesday...SCA conditions expected (100%) with 25-30 kt wind gusts and 5 to 8 foot seas.

Wednesday Night...SCA conditions expected (100%) with gales likely (60-80%). A Gale Watch was issued for Delaware Bay and all coastal zones except ANZ450 as wind gusts up to 40 kt are possible in these locations with the passage of a strong cold front.

Thursday...SCA conditions expected (100%) with 25-30 kt wind gusts and 4 to 7 foot seas.

Thursday Night...Conditions quickly drop below SCA-levels, though some lingering 5 foot seas are possible (30-40%) for the first half of the night.

Friday...No marine headlines expected.

HYDROLOGY
The Tuesday through Wednesday Night system will bring a widespread 2 to 3 inches of rain with rainfall likely being heavy at times. Given low stream levels, and most of the area still being in moderate to extreme drought, flooding concerns should mainly be confined to urban and poor drainage areas (make sure to clear out any drains clogged with falling leaves!). Even ensemble river forecasts show less than a 30% chance of hitting action stage for nearly all forecast points.

NBM Probabilities of 2+ inches are around 80-90% regionwide for the 48 hour period ending Thursday morning, meaning there is high confidence in totals generally falling somewhere in the 2 to 3 inch range. Cannot rule out some higher amounts, especially along the coast and in northern New Jersey, as the development of a coastal front could enhance precipitation rates a touch. Probability of 3+ inches of rain within the 48 hour period ending Thursday morning is around 30-45% for the NJ coastal plain, with around 15-30% for the rest of the area. A MARGINAL (1/4) risk for excessive rainfall is in place, which is about right given the limiting factors mentioned above.

PHI WATCHES/WARNINGS/ADVISORIES
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Gale Watch from Wednesday evening through late Wednesday night for ANZ430-431-451>455.
Small Craft Advisory from noon today to midnight EST tonight for ANZ451>455.