Marine Weather and Tide Forecast for Jim Thorpe, PA

NEAR TERM /THROUGH TUESDAY/
As of 640 PM, high level cloudiness continues to increase from the south this evening. The main adjustment to the forecast with this update was to slow down the northward PoP increase. An initial band of showers looks to weaken or be very light as it lifts northward across Delmarva due to some lingering dry air.
Made some adjustments to the hourly temperature and dew point grids especially based on the latest observations and trends.

Otherwise, clouds will continue to increase, thicken and lower through the overnight from south to north as low pressure begins to inch towards the region. Showers will start to increase from south to north overnight. South to southeast winds will become light to even locally variable/calm.

Tuesday will continue to see an onshore flow for our area as low pressure moves across the Carolinas. Showers and a small chance for a thunderstorm are expected for much of the day, with this more widespread during the afternoon. The best chance for thunder will be across some areas west of Philadelphia with somewhat more unstable air arriving (aloft) there. Temperatures Tuesday will remain below average with all the clouds, showers and onshore flow, only reaching the upper 60s or low 70s most spots. Rainfall totals through the day will range from less than a tenth of an inch for the northeast areas to around a half inch for metro Philadelphia and Delmarva.

SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
Closed upper lever low centered over Kentucky Tuesday evening will move north into Ohio by Wednesday morning, gradually opening up into a shortwave trough as it heads towards Detroit by Wednesday evening. The remnant low heads towards Toronto by Thursday morning and on towards Montreal by Thursday evening.
Its during the day Thursday when the upper trough axis crosses our region, ending up just northeast of us by Thursday evening.
At the surface, a slow moving, weak and diffuse low pressure will gradually head northeastward from the Carolinas Tuesday evening to our vicinity Wednesday night, pushing northeast of us Thursday. This weak low will be accompanied by a warm front, which means that while Wednesday will be on the cool, cloudy side, Thursday should see a bit more sun, more instability, and a better chance for a few thunderstorms. Overall, Tuesday night through Wednesday looks pretty wet, with plenty of showers, but meager instability. Thursday will be drier, but spotty thunderstorms will be a bit more of a risk, mainly inland away from the marine influence, but with less rain on average. Lows both nights will be 50s north, 60s south. Highs Wednesday will be 60s north and east of Philly, 70s south and west, while highs Thursday will be 70s except along the shore and in the Poconos where upper 60s remain, while it may touch 80 in parts of the Delmarva.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
Weak ridge builds in Thursday night, with finally a mostly dry period for the first time since today. Lows will be in the mild 60s for most.

Cold front approaches from the west Friday afternoon, so while a mostly dry morning is likely, chance of showers and thunderstorms increases in the afternoon. Could be a severe weather risk, but still a ways off. Highs up near 80.

Front passes east during Friday night, with waning precip risk.
Not much of a colder push with this front, so lows again mostly 60s.

A second cold front then approaches for Saturday afternoon, with another mostly dry morning followed by a stormier afternoon. Highs again mostly near 80.

That front passes east Saturday night, with again a waining precip risk. Another front with minimal cold push, so lows again mostly in the 60s.

A third cold front then moves through by late Sunday, with less moisture to work with but more of a cold air push. Thus, while highs will again be near 80, chance of precip doesn't increase all that much during the day and tanks at night, with lows dropping into the 50s for most. Highs on Monday then stay mostly in the 70s.

AVIATION /22Z MONDAY THROUGH SATURDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Tonight...VFR ceilings lowering with some MVFR ceilings developing for some areas toward daybreak. Some showers should also develop towards daybreak especially south of KPHL. South to southeast winds 5-10 knots, becoming locally light and variable to calm.
Low confidence regarding timing details of MVFR ceilings.

Tuesday.. MVFR ceilings lower to IFR through the day. Showers increasing will result in MVFR/IFR visibilities at times. A couple of thunderstorms cannot be ruled out mainly west and south of KPHL later in the afternoon. Light and variable to east-southeast winds near 5 knots, increasing to around 10 knots. Some local gusts to 15-20 knots possible toward late afternoon. Low confidence on timing details and if any thunder occurs.

Outlook...

Sub-VFR with intervals of IFR likely through Thursday with showers and a few thunderstorms. Conditions should improve a bit Friday and Saturday with less chance of showers, but still a chance of thunderstorms.

MARINE
Sub-SCA conditions through tonight. On Tuesday, onshore winds will increase through the day and seas will build as well with Small Craft Advisory conditions starting to develop toward early evening.

Outlook...

Small Craft Advisory conditions develop across most water Tuesday evening and spread to all waters after midnight, with gusts up to 30 kts and ocean waves up to 7 feet. Southern waters and the bay will see conditions begin to relax after dawn Wednesday, but central and northern waters won't peak until Wednesday morning, then relax Wednesday afternoon. Winds likely drop below SCA levels by late Wednesday afternoon, but SCA waves thresholds of 5 feet may persist on the ocean waters until during the day on Thursday. Showers and spotty thunderstorms will also be a concern on the waters through this entire period.

Sub-SCA conditions should then take hold by Thursday evening and continue through Saturday. However, showers and spotty thunderstorms may continue to be a risk through Saturday, especially during the afternoon and evening hours.

TIDES/COASTAL FLOODING
Prolonged southeasterly flow will lead to an increase in surge values as the week progresses, especially for the upper Delaware Bay and tidal Delaware River. Surge values are forecast to peak as much as 1-2 feet above normal. As a result, minor coastal flooding is forecast with the overnight high tide cycles beginning Tuesday night and continuing through at least Wednesday or Thursday night.

A Coastal Flood Advisory was issued to highlight the threat of minor coastal flooding for these areas. Additional advisories or extensions may be needed in future updates.

PHI WATCHES/WARNINGS/ADVISORIES
PA...Coastal Flood Advisory from 1 AM to 6 AM EDT Wednesday for PAZ070-071-106.
NJ...Coastal Flood Advisory from 10 PM Tuesday to 2 AM EDT Wednesday for NJZ016.
Coastal Flood Advisory from 1 AM to 6 AM EDT Wednesday for NJZ017>019.
DE...Coastal Flood Advisory from 10 PM Tuesday to 2 AM EDT Wednesday for DEZ001.
MD...None.
MARINE...Small Craft Advisory from 5 PM Tuesday to 8 AM EDT Wednesday for ANZ430-431-451>455.
Small Craft Advisory from midnight Tuesday night to 8 AM EDT Wednesday for ANZ450.