Marine Weather and Tide Forecast for Philadelphia, PA

NEAR TERM /THROUGH TUESDAY/
An increase in clouds in response to some upper level energy passing through the area this afternoon may result in some snow showers or flurries across the Poconos and Lehigh Valley. Any snow showers will conclude by early evening and any accumulation would be negligible. Elsewhere, mostly cloudy skies and dry weather is expected.

Surface high pressure settles off to our south tonight before gradually shifting off the Southeast coast on Tuesday. Skies will clear out overnight and winds will diminish and become light and variable at times. Another cold night is expected as much of the area should be able to radiate pretty well. As a result, lows should tank and bottom out in the low to mid teens with single digits in the higher elevations. With light winds, wind chills won't be far off from actual air temperatures overnight.

For Tuesday, with the high slowly sliding off the coast, the region will begin to encounter southwesterly return flow. This should allow temperatures to moderate a bit where highs will mainly be in the 30s (20s in the higher terrain). Sunny skies should prevail in the morning, with an increase in clouds in the afternoon as another upper level disturbance approaches later in the day. No precipitation is expected.

SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
High pressure settles off the Southeast coast Tuesday night, and while return flow sets up, the combination of skies clearing out enough with winds light enough and with lingering snowpack that temperatures should radiate down into the teens and low 20s.

Zonal flow sets up on Wednesday and a weak trough approaches from the west. Temperatures begin to moderate somewhat, but will still be below normal levels topping off in the low to mid 40s.

High pressure then builds back over the area for Wednesday night and Thursday. Still cold Wednesday night with lows in the 20s, but then highs rebound on Thursday to above normal levels in the upper 40s to low 50s north and west of the Fall Line and in the low to mid 50s across the Delaware Valley, Delmarva, and southern New Jersey.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
High pressure moves out to sea Thursday night, and low pressure passing through the Great Lakes will drag a cold front into the region late Thursday night and Friday. Temperatures will be warm enough for this to be a mostly rain event, though with cold air advection on the back side of the system, there may be some rain/snow mix in the southern Poconos and portions of the Lehigh Valley. There are some signals for some moderate to possibly even heavy rainfall over the area with this system. The bulk of the rain, at least at this time, looks to fall between midnight or so Thursday night through Friday afternoon. 13Z NBM probability of 24 hour precipitation ending 7 pm Friday is 70 to 80 percent for greater than 0.5 inches and 40 to 60 percent for greater than 1 inch. Lows Thursday night will be in the upper 30s to low 40s, and then highs on Friday will be in the upper 40s to low 50s. This rainfall should take care of the bulk of the snowpack over the area.

Cold front passes through by Friday night and then Arctic high pressure builds back into the region with lows in the 20s Friday night and then highs in the upper 30s to low 40s on Saturday.
Some strong shortwaves will pass through the region with minimal impacts.

High pressure slides offshore Saturday night and temperatures rebound on Sunday with highs in the mid to upper 40s. A weak front may pass through the region Sunday night and then high pressure returns on Monday with near to slightly below normal levels.

AVIATION /19Z MONDAY THROUGH SATURDAY/
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Rest of Today (through 23Z)...VFR with mid-high level clouds.
West-northwest winds around 10 kt. A slight chance of a snow shower at KABE and KRDG. High confidence.

Tonight...VFR. Decreasing clouds. Southwest winds around 5 kt or less, becoming light and variable at times. High confidence.

Tuesday...VFR. Clear skies in the morning, with increasing clouds in the afternoon. West-northwest winds in the morning around 5-10 kt, settle out of the west-southwest in the afternoon. High confidence.

Outlook...

Tuesday through Thursday...VFR/NSW.

Thursday night through Friday...Sub-VFR conds in RA through Friday afternoon. SW winds gusting 25 to 30 kt Thursday night, turning W-NW on Friday.

Friday night through Saturday...VFR/NSW.

MARINE
As of 2:00 PM, all remaining Small Craft Advisories have either been allowed to expire or cancelled. No further marine headlines are expected through Tuesday.

West winds this afternoon will settle out of the west-southwest around 15-20 kt tonight with seas of 2-4 feet. For Tuesday, west-northwest winds around 10-15 kt and seas of 1-3 feet are expected. Fair weather.

Outlook...

Tuesday night...Sub-SCA conditions.

Wednesday...Marginal SCA conditions may develop with gusts up to 25 kt and seas building to 5 feet.

Wednesday night through Thursday...Sub-SCA conditions.

Thursday night through Friday...Strong SCA conditions developing with gales possible on Friday. VSBY restrictions in rain and fog.

Friday night...SCA conditions.

Saturday...Sub-SCA conditions.

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