textproduct: Philadelphia/Mt Holly

SYNOPSIS

A high pressure system moves in for tonight through Tuesday morning. Our next frontal system arrives for mid-week. High pressure takes over in the wake of the frontal system for the end of the week and beginning of the weekend which results in dry but windy and cold conditions.

NEAR TERM /THROUGH MONDAY/

The base of an H5 trough with strong shortwave energy passes through eastern Pennsylvania, central New York and northern New Jersey this evening before tracking east and moving offshore late tonight. As this trough departs, its will drag a cold front through the region. High pressure then builds into the Ohio and Tennessee Valleys before moving off the Mid-Atlantic coast late Monday.

In terms of sensible weather, generally quiet conditions for most of the region. At this point, it looks the remaining showers will stay north of the region as the front passes. Can't completely rule out a stray shower grazing the region north of I-80 but any QPF will be minimal so PoPs are less than 15 percent for tonight.

For the rest of the area, skies have largely cleared out with the dissipation of the daytime stratocumulus. Despite clearing skies, winds should be elevated enough to keep optimal radiational cooling conditions from developing. Not much cold air advection behind this front. Lows will be in the low to mid 30s.

There may be a quick surge in northwest winds Monday morning after sunrise, generally 10 to 15 mph with gusts up to 20 mph. Winds should settle down in the afternoon and back to the west as high pressure builds east. Generally partly to mostly sunny skies with highs in the low to mid 50s.

SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/

We start the short term period tranquil with a high pressure system overhead Monday night but it does move offshore on Tuesday. Clouds do increase Monday night ahead of our system arriving Tuesday. Lows Monday night are in the 30s.

On Tuesday, a warm front will be lifting northward through the area which is attached to a deepening low pressure system near the Great Lakes region. This warm front along with the high pressure system moving offshore will set the stage for warmer air to filter in Tuesday into Tuesday night. We are cloudy Tuesday with rain starting to move in during the morning to midday hours. Coverage does pick up across the area through Tuesday with the best coverage Tuesday afternoon into Tuesday night. Highs on Tuesday are in the low 50s to low 60s. Our lows Tuesday night are in the mid 40s to mid 50s.

Periods of rain continue Wednesday into Wednesday night. The first cold front with the deepening low now moving into Canada will move through Wednesday night with our first round of cold air filtering in behind it. Highs on Wednesday are in the 60s for most. By Wednesday night, lows are in the 30s for many. The rainfall totals across the area generally look to be a quarter of an inch to half an inch. This rain looks to be beneficial more than anything with Tuesday through Wednesday night being a damp and dreary stretch.

LONG TERM /THURSDAY THROUGH SUNDAY/

The secondary cold front comes through on Thursday which will usher in more cold air leading to strong cold air advection. Also, an incoming area of high pressure from the west and the departing low pressure system to the north in Canada will set up a tight pressure gradient. The result will be a windy end of the week. The general messaging at this time for Thanksgiving and Black Friday is that both days look dry but cold and windy.

By Friday night, our high pressure system slides in from the west and then moves overhead into Saturday which will put an end to the windy conditions. Still looking at below normal temperatures for next weekend, though with some moderation. Dry weather should continue through at least Saturday with the high in the vicinity of the Mid-Atlantic.

AVIATION /00Z MONDAY THROUGH FRIDAY/

The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Tonight...VFR with mostly clear skies. W-NW winds 5 to 10 kt. High confidence.

Monday...VFR. NW winds 10 to 15 kt with a few gusts to 20 kt in the morning, becoming W around 5 kt in the afternoon. High confidence.

Outlook...

Monday night...VFR. No significant weather.

Tuesday...VFR to start. Conditions deteriorating through the day with MVFR by the late afternoon/early evening with rain showers moving in.

Tuesday Night through Wednesday...MVFR/IFR conditions expected with periods of rain and low clouds in place.

Wednesday Night...Conditions likely improving to VFR late, but MVFR/IFR restrictions possible (40-60%) for at least part of the night.

Thursday and Friday...VFR. Wind gusts out of the west/northwest around 25-30 kt.

MARINE

Southwest winds 10 to 15 kt will veer to the northwest and increase to 15 to 20 kt with gusts up to 25 kt this evening behind a cold front. A Small Craft Advisory is in effect for the ocean and for Lower Delaware Bay for tonight through late Monday morning. Winds diminish to 5 to 10 kt Monday afternoon. Seas generally 2 to 4 ft, through there may be a brief period of 3 to 5 ft seas on the ocean late tonight and into Monday morning.

Outlook...

Monday Night through Tuesday...No marine headlines expected.

Tuesday Night...SCA conditions possible (40-50%), especially on the ocean waters with wind gusts out of the south/southwest nearing 25 kt and seas 3 to 5 feet.

Wednesday...SCA conditions possible (40-60%) with seas near 5 feet.

Wednesday Night...SCA conditions expected with wind gusts 25-30 kt and seas 4-6 feet.

Thursday through Friday...SCA conditions expected with potential for gales (50-70%) with brisk west/northwest winds 30-35 kt. Seas 4- 6 feet.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 1 PM EST Monday for ANZ431-450>455.