Marine Weather and Tide Forecast for Heller, PA

KEY MESSAGES
1. A warm front north lifts north through the region tonight through Wednesday. Low pressure then lifts north through the region Wednesday.

2. For the later half of the week, we will have a hot, humid, and at times stormy pattern in place.

DISCUSSION
KEY MESSAGE 1...A warm front north lifts north through the region tonight through Wednesday. Low pressure then lifts north through the region Wednesday.

High pressure over New York and Pennsylvania pushes out to sea tonight. Meanwhile, Low pressure tracks along the Eastern Seaboard and passes out to sea. Behind this low, a warm front will lift north through the region late tonight through Wednesday morning.

Clouds will lower and thicken late tonight, and some patchy fog may develop as low level moisture increases over the area behind the warm front lifting through the region. Surface dew points generally in the mid 60s will rise into the upper 60s and low 70s late tonight and Wednesday morning. Increasing southerly flow on Wednesday will push dew points up into the low to mid 70s Wednesday afternoon. With highs in the low to mid 80s, max heat index values will be in the upper 80s to low 90s.

Another weak area of low pressure will track north Wednesday afternoon, mainly west of the Appalachians and west of the I-95 corridor into eastern Pennsylvania late Wednesday.

In terms of precipitation, some showers will develop in the morning with the passage of the warm front, and then another round of showers and scattered thunderstorms will develop in the afternoon. The primary concern is for heavy rain leading to flash flooding, but when it comes to a hot and humid airmass, a few strong to severe thunderstorms cannot be ruled out.

The Weather Prediction Center has a Marginal Risk (1 out of 4)
for Excessive Rain on Wednesday. Rainfall amounts will be light in the morning. While overall basin averages will generally be 1/4 to 1/2 inch of rain, there is the potential for training leading to localized rainfall totals in excess of 1 inch. With most of that rain occurring in the afternoon, that creates the potential for flash flooding.

KEY MESSAGE 2...For the later half of the week, we will have a hot, humid, and at times stormy pattern in place.

Expect a prolonged period of southwesterly flow as our region will be in between a Bermuda High well to our east, and a mid level long wave trough that will be slowly sliding east over the northern tier of the U.S./southern Canada. As such, it will be hot and humid for the later half of the week and weekend with maximum temperatures each day ranging from the low 80s (Poconos)
to the low 90s (metro). However, with dewpoints from 70F to 75F, heat index values at or above 100 degrees are possible for much of the area.

The other aspect of this are the daily storm chances, primarily confined to the afternoon and evening with a typical diurnal pattern. Given the hot and humid conditions that will be in place, we can't rule out the more common thunderstorm hazards of damaging winds and heavy rain/flooding. If an embedded short wave trough crosses our region as the larger trough axis approaches, that could increase the risk, particularly for severe threats, but trying to time that out at this point would be very difficult, given that we are still seeing some differences between the models with the larger pattern.

AVIATION /20Z TUESDAY THROUGH SUNDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Rest of today...VFR. E to SE winds 10 kt or less. High confidence.

Tonight...VFR most of the night, then MVFR conds develop after 09Z in BR and stratus. E to SE winds less than 5 kt. Moderate confidence.

Wednesday.. MVFR conds throughout the day. SHRA in the morning, then SHRA and TSRA in the afternoon. SE winds less than 10 kt.
Low confidence.

Outlook...

Wednesday night.. MVFR or lower possible in SHRA and TSRA.

Thursday through Sunday...Periods of MVFR or lower in afternoon and evening SHRA/TSRA.

MARINE
Sub-Small Craft Advisory conditions tonight through Wednesday.
East winds 10 to 15 kt become southeast less than 10 kt, then Winds become south Wednesday afternoon at 10 to 15 kt. Seas will average 2 to 3 feet.

Visibility restrictions develop in fog and showers late tonight and Wednesday morning, then afternoon showers and scattered thunderstorms will develop Wednesday afternoon.

Outlook...

Wednesday night through Sunday...Overall, a prolonged period of sub-SCA conditions, however there is a chance for 25+ kt wind gusts Thursday night. Afternoon and evening showers and thunderstorms possible as well.

Rip Currents...

For Wednesday, winds becoming southeasterly near 10 mph. Breaking waves in the surf zone of 1-3 feet are forecast with a medium period swell. Given the more onshore component for most of the Jersey Shore, maintained a MODERATE risk for the development of dangerous rip currents. Breaking waves look to be a little lower for the Delaware Beaches with a more parallel wind therefore went with a LOW risk for the development of dangerous rip currents.

For Thursday, south to south-southwest winds increase to 10-20 mph.
Despite the increasing wind and it becoming more parallel to the coast and the breaking waves forecast to be a little lower, a longer period swell may arrive. Opted to go with a MODERATE risk for the development of dangerous rip currents for the Jersey Shore, and a LOW risk for the development of dangerous rip currents for the Delaware Beaches.

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