Marine Weather and Tide Forecast for Colwyn, PA

NEAR TERM /THROUGH TONIGHT/
High pressure moves offshore on Monday. We will still feel some lingering influence from this high pressure system which keeps us dry during the day with a partly to mostly cloudy sky. Winds turn to be more out of the south during the day at 5-10 mph with gusts upwards of 20 mph at times. High temperatures reach the upper 50s to upper 60s across the area.

A warm front starts to move into the area Monday evening into Monday night. This starts to lead to the chance for some showers. These showers will be scattered in coverage at times. Overnight, a cold front starts to push east which still keeps the chance for some showers going into early Tuesday morning. Due to this cold front, winds change to be more out of the west by the early morning hours of Tuesday. Lows Monday night are in the upper 40s to upper 50s.

SHORT TERM /TUESDAY THROUGH THURSDAY/
A cold front sweeps the marine layer back out to sea on Tuesday, with any lingering showers rapidly ending and clouds breaking for some sun on a gusty west-northwest wind. However, this will be a well mixed wind with downsloping, so we'll actually warm up by comparison to Monday. Most areas, even the coast, likely reach the 70s, with warmest spots touching 80.
Poconos however may only reach the 60s.

High pressure builds in from the northwest behind the front for Tuesday night, with diminishing winds. However, front doesn't make it too far south and we may get clouds developing across the region on the north side, mainly of the mid and high variety. Lows in the upper 40s north of Philly, 50s from Philly southwards.

Wednesday looks like a sunnier day overall with the high helping push the front further south by this point. So have generally mostly sunny in the forecast, but with a colder air mass well- entrenched by this point and lighter winds, it'll be a little cooler than Tuesday. Highs in the low-mid 70s, but not likely to see 80 anywhere, with 60s along the coast and in the Poconos.

Wednesday night looks similar to Tuesday night with light winds, but a bit less cloud cover. Lows again in the 40s north of Philly, 50s from Philly south. High pressure remains in control for Thursday, but shifts east, allowing a bit of warm advection to begin. Highs will tick up a little inland, mid-upper 70s, but with a bit more southeasterly fetch, expect more marine influence, so coastal areas may actually be a little cooler.

LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/
The next front begins to infringe on the area Thursday night into Friday before slowly crossing the region Saturday. Still a bit of uncertainty on timing. PoPs still increase Friday night but the highest PoPs are now daytime Saturday. Could be some convective concerns, but the timing issue makes that tricky to determine this far out. For that reason have only included a chance of thunder at this time. Marine layer could also limit instability if that becomes a factor. Highs near 70 ahead of the front Friday rise back to mid 70s Saturday as the front passes, then drop into the 60s as we dry out and cool off behind the front with high pressure returning on Sunday. Lows Thursday night and Saturday night will be low-mid 50s, while many areas could stay near or above 60 Friday night just ahead of the front.

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

Monday...VFR. Ceilings lower throughout the day with cloud bases as low as 4000-6000 feet. Winds change from being more easterly in the morning to more southerly by the evening. High confidence.

Monday Night.. MVFR/IFR conditions. Rain showers move through overnight. Ceilings will lower to MVFR around 00Z and then IFR around 04Z-06Z. There also looks to be the potential for LLWS at KACY and KMIV from around 02Z through 06Z out of the south at 2000 feet at 40 knots. Surface winds change from the south to more westerly overnight and decrease to be around 5-10 knots.
After 12Z, ceiling start to lift and rain showers move out. Moderate confidence.

Outlook...

Tuesday through Thursday...VFR with no significant weather expected.

Friday...Sub-VFR conditions possible with a chance (25-35%) for showers.

MARINE
High pressure remains in control for Monday leading to fair weather conditions. Winds change from being more easterly to more southerly during the day. The chance for some rain showers look to move in for Monday night into Tuesday morning. Winds also change from being southerly to more westerly by Tuesday morning. Overall, seas and wind speeds look to stay below SCA criteria through Monday night.

Outlook...

Tuesday through Friday...Conditions are expected to generally remain below Small Craft Advisory criteria.

FIRE WEATHER
On Monday, fire weather concerns diminish as min RH values look to range from 35-45% which is higher than what we saw over the weekend. A more easterly wind Monday looks to be more southerly by the late afternoon. Winds will be sustained at 5-10 mph with gusts upwards of 20 mph at times.

Fire weather concerns may increase again for Tuesday with minimum RHs down near 30 percent and winds gusting up to 25 mph. However, the risk may be limited depending on just how much rain falls Monday night.

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