textproduct: Philadelphia/Mt Holly

SYNOPSIS

An area of low pressure moves through this morning with a weak clipper system passing by to the north on Sunday. High pressure moves in Sunday Night through Tuesday morning, with a frontal system moving in for the mid-week period. High pressure takes over in the wake of the frontal system for the Thanksgiving holiday through the end of the week, resulting in dry but cold weather.

NEAR TERM /THROUGH TONIGHT/

An upper-low initially located over Quebec will track eastward to our north through the period. A weak shortwave will track out of the Ohio Valley region and through our area by this afternoon. Enhanced northwesterly flow will commence after the passage of the shortwave and continue through tonight. At the surface, a weak and broad area of low pressure and an associated frontal boundary will track through the region by midday, with high pressure building in through tonight.

Light rain is currently overspreading the area, and will continue through the overnight hours. The rain will begin to come to an end from west to east during the morning hours, with most locations dry by midday. A few lingering showers will be possible into the early afternoon for the Delmarva and far southern NJ before all rain comes to an end. Expected rainfall amounts have not changed much, with locations south of I-78 seeing generally around 0.25" with isolated higher amounts near 0.50" possible. North of I-78, amounts will be a bit lighter, generally between 0.10-0.20". Temperatures this morning will bottom out in the mid 40s, with upper 30s possible for the higher elevations.

Skies will begin to clear from northwest to southeast this afternoon, with partly to mostly clear skies for most by sunset. Highs today will generally be in the low-mid 50s. Partly to mostly clear skies will continue through the night tonight. A widespread freeze is expected, with mid-upper 20s expected across much of eastern PA and NJ away from the urban corridor and the coastal plain. Low-mid 30s are expected for the Delmarva, urban corridor, and NJ coastal plain.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

High pressure moves offshore on Sunday, with a weak clipper system sliding by to the north to close out the weekend. Most will see no impacts from this system as it passes, but cannot rule out a few rain/snow showers, mainly from I-78 on north, with the highest chance to see flakes (20-30%) being in the higher elevations of Carbon/Monroe County in PA and Sussex County, NJ in the morning when temperatures are still cold enough for snow showers. Outside of any showers, it will be partly cloudy overall with highs in the low to mid 50s, with mid to upper 40s in the higher elevations.

An expansive area of high pressure moves in behind the clipper system, resulting in a tranquil period of weather Sunday Night through Monday Night. Overnight lows both Sunday and Monday Night will hover in the low to mid 30s with highs on Monday in the low to mid 50s.

LONG TERM /TUESDAY THROUGH FRIDAY/

High pressure quickly moves offshore by Tuesday morning with an area of low pressure moving through the upper Great Lakes. This will drag a warm front through our area on Tuesday Night, with the associated cold front pushing in on Wednesday. The result will be periods of rain likely beginning by Tuesday evening, continuing through Wednesday night. Rain won't be continuous and this does not look like an impactful system overall. NBM probability of 24 hour rainfall > 1 inch is only around 10%, so this looks to be a beneficial rain more than anything. Temperatures turn to the mild side with the warm front coming through, especially on Wednesday where a stretch of above normal temperatures expected, making this an all rain event.

Temperatures take a tumble for the end of the week. The initial cold front moves through on Wednesday, with a secondary reinforcing front on Thursday Night. This will usher in a stretch of below normal temperatures for late November, though at the very least the Thanksgiving holiday looks dry at this point.

AVIATION /08Z SATURDAY THROUGH WEDNESDAY/

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

Through 12Z...MVFR ceilings to start, lowering to IFR through 09- 11Z. Light rain will impact all terminals through the period. Visibility restrictions are likely as well. Light and variable wind with periods of calm. Moderate confidence overall, low confidence in timing and extent of lowest ceilings.

Today...IFR ceilings to start, lifting to MVFR 14-17Z and eventually lifting or scattering out to VFR mid-late afternoon. Light rain will end from west to east, clearing all terminals by afternoon. Light wind will become north-northeasterly and eventually north- northwesterly around 5 kt. Moderate confidence overall, low confidence in timing of improvement in flight categories.

Tonight...VFR. Light wind favoring a northerly direction. High confidence.

Outlook...

Sunday through Tuesday...VFR. No significant weather.

Tuesday Night through Wednesday...sub-VFR conditions expected with periods of showers and low clouds.

MARINE

No marine headlines through tonight. Winds will increase this afternoon, generally out of the north at 15-20 kt. Winds will again decrease tonight. Seas 2-3 feet. Rain will be likely through mid- afternoon. Fair weather thereafter.

Outlook...

Sunday...No marine headlines expected.

Sunday Night through Monday...SCA conditions possible (50%) as wind gusts approach 25 kt.

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

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...None.