Marine Weather and Tide Forecast for Cochranville, PA

KEY MESSAGES
1. Above average temperatures continue today into Saturday.
Some showers and thunder for parts of the area today into early this evening.

2. Widespread minor tidal flooding is forecast to occur along the Atlantic coasts of NJ and DE, Delaware Bay, and the tidal Delaware River with the Saturday evening/night high tide.

3. A strong cold front will cross through the area Sunday morning, resulting in a period of showers and some thunderstorms along with cooler and breezy conditions.

4. Much cooler, below normal temperatures are expected into early next week. Widespread frost and/or freeze appears likely Monday night into Tuesday morning.

DISCUSSION
KEY MESSAGE 1...Above average temperatures continue today into Saturday. Some showers and thunder for parts of the area today into early this evening.

An upper-level trough axis is forecast to slide across our area during today. This will break down the pattern that has brought record warmth to most of the region. While temperatures today will still be well above average, highs will be about 10 degrees lower than yesterday. The presence of the upper-level trough and its associated cooling aloft will also result in additional clouds developing during daytime heating. In addition, enough instability develops for some showers to occur especially from about the I-95 corridor on eastward especially this afternoon.
The model forecast soundings show skinny instability (CAPE)
profiles with this being at and below 20,000 feet. This would result in low-topped convection which may produce little or no lightning. The coverage of the showers through the day, especially this afternoon, looks to be isolated to scattered as the overall forcing is not strong. The low- level flow is forecast to become lighter as the afternoon wears on, therefore a sea breeze circulation should develop and once again result in it being cooler along the coast.

The warmth continues into Saturday, however a northeast to east low- level flow will become established as a backdoor front pushes southwestward. This will result in much cooler temperatures closest to the coast with the warmest on Saturday across our western zones. Some guidance is rather robust with the marine influence, especially as the boundary layer warms up quite a bit inland, and therefore shoves the cooling farther inland by late afternoon. High temperatures still above average Saturday, however they will continue to step downward as we get much closer to a more significant pattern change.

KEY MESSAGE 2...Widespread minor tidal flooding is forecast to occur along the Atlantic coasts of NJ and DE, Delaware Bay, and the tidal Delaware River with the Saturday evening/night high tide.

High astronomical tides associated with the new moon occurring today and persistent onshore flow developing tonight and especially Saturday is forecast to result in widespread minor tidal flooding with the Saturday evening/night high tide along the Atlantic coasts of NJ and DE, Delaware Bay, and the tidal Delaware River. Some spotty minor tidal flooding may occur in some areas with the high tide this evening/tonight, though any impacts will be limited enough to preclude and advisory. As southeast winds persist on Saturday, surge values will increase to near 1 foot above normal, which will put most tidal areas into minor flood stage during high tide Saturday evening/night.
This may warrant an advisory with a future update.

A modest offshore wind will develop in the wake of a cold front on Sunday, which should limit the threat of any additional flooding for Sunday night's high tide.

No tidal flood is forecast for the Eastern Shore of Chesapeake Bay.

KEY MESSAGE 3...A strong cold front will cross through the area Sunday morning, resulting in a period of showers and some thunderstorms along with much cooler and breezy conditions.

A deep upper trough will approach the region Saturday night. A strong cold front will precede this trough and slide across the region late Saturday night into Sunday morning. A weak area of low pressure may also develop along the front in our vicinity.
As the main trough axis hangs back farther to the west, much of the shower activity may occur behind the actual front. Given the strength of the incoming upper-level trough, forcing for ascent should be strong enough to result in widespread shower coverage, or even stratiform rain for a time. The thunder risk at this time looks rather low given the timing of the front, however some rumbles of thunder cannot be ruled out.

This will be beneficial rain, and it will also usher in a significant cool down into early next week. Rainfall amounts look to be around 0.10-0.25" along and southeast of I-95, and perhaps as much as 0.50" toward I-78 and points north of there.

A gusty northwest wind will also occur in the wake of the cold front on Sunday, with gusts of 25-35 mph possible across the area. Highs Sunday will only be in the 50s to low 60s in most areas. Skies will be mostly cloudy. However, if some sun can break through the clouds late in the day, temperatures may warm some before dark.

KEY MESSAGE 4...Much cooler, below normal temperatures are expected into early next week. Widespread frost and/or freeze appears likely Monday night into Tuesday morning.

Lingering gradient wind and cold advection Sunday night into Monday morning should limit frost formation, despite temperatures dropping into the 30s in many areas. Temperatures will likely fall to near or just below freezing north of I-78, which may warrant freeze headlines for these areas (save for the southern Poconos, where the growing season has not begun).

Temperatures Monday will be quite chilly compared to our recent record breaking warmth, with highs only in the mid 40s to mid 50s. This will be about 10-15 degrees below normal. Breezy northwest winds will continue as well, with gusts up to 30 mph possible under partly cloudy skies.

Much lighter winds and a colder airmass with high pressure settling overhead should set the stage for widespread frost and/or freeze conditions Monday night into early Tuesday morning. Forecast low temperatures by Tuesday morning range from the mid 20s to mid 30s. Temperatures will begin to rebound Tuesday as airmass modification begins with highs in the mid 50s to low 60s. Temperatures Tuesday night should be mild enough to preclude any frost/freeze concerns, with lows mainly in the 40s.

Temperatures will rebound slight above normal by the middle to end of the week with limited chances of convection.

AVIATION /12Z FRIDAY THROUGH TUESDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Today...VFR overall with a ceiling between about 5,000-10,000 feet AGL. Northwesterly winds diminish to near 5 knots early this morning then increase to 8-12 knots. Some wind gusts up to 20 knots possible later this morning into this afternoon. A few showers through the day with isolated thunder possible, especially later this afternoon (PROB30 included at most terminals). Low confidence on timing/coverage details of showers.

Tonight...VFR with increasing clouds, then MVFR or IFR ceilings develop overnight from east to west. North-northwest winds 5-10 knots, becoming northeast near 5 knots. Low confidence regarding MVFR ceiling details and if any local fog develops.

Outlook...

Saturday.. MVFR ceilings possible to start, then VFR.

Saturday night through Sunday night...Restrictions likely at times. Widespread showers developing by early Sunday morning, with perhaps an isolated thunderstorm. Northwest winds will become increasingly gusty by Sunday afternoon with gusts up to 30 kts possible.

Monday through Tuesday...VFR. Wind gusts up to 25 kt possible on Monday, otherwise no significant weather expected.

MARINE
The conditions are anticipated to remain below Small Craft Advisory criteria through tonight. A wind shift to the northwest then north and eventually from the northeast is expected today into tonight.

Outlook...

Saturday...The conditions are anticipated to be below Small Craft Advisory criteria.

Saturday night through Monday...Small Craft Advisory conditions likely due to wind gusts around 25-30 kt. Otherwise, no marine headlines are expected.

Monday night through Tuesday...No marine hazards expected.

PHI WATCHES/WARNINGS/ADVISORIES
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.