textproduct: Philadelphia/Mt Holly

SYNOPSIS

A weak area of high pressure will extend from the Ohio Valley to Delmarva into the weekend. An area of low pressure tracks south of our region Saturday night into early Sunday, while another one tracks to our north. High pressure builds in for Monday before shifting offshore into Tuesday. A cold front crosses our area later Wednesday, with high pressure arriving for Thursday.

NEAR TERM /THROUGH SATURDAY/

Overnight, we see more of a west-northwest wind which will still allow some of the upstream lake effect moisture to keep clouds around longer across our NW zones and perhaps some pockets of flurries or a light snow shower. Clouds will continue to decrease tonight and we trend drier. This is as a high pressure system starts to build in from the west. Lows tonight are in the teens for most.

On Saturday, we see clouds increase from the south as a low pressure system develops across the southeast U.S. and travels off to the northeast. Most of Saturday looks dry with highs mainly in the 30s.

SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/

As an upper-level trough moves across the East Saturday night into early Sunday morning, surface low pressure will shift eastward and track well to our south. The model consensus is for the precipitation shield to remain south of our entire region, although this will depend on if the trough aloft sharpens up a bit more. If this would to occur then the southern energy phases more with the northern energy. Still have some slight chance (20 percent) to low chance (30 percent) PoPs for much of the area (highest closer to the coast). It is quite possible that our region sees no precipitation from this system as it quickly moves out to sea very early Sunday morning. Some guidance however is a little sharper with the northern energy and therefore brings some light snow to our northern areas Saturday night.

For the remainder of Sunday, high pressure continues to move eastward and allows for clouds to decrease. Highs on Sunday are mostly in the 30s, and there will be a northwest breeze which will add to the chill. Surface high pressure builds in Sunday night, keeping the forecast dry. Lows will be in teens and 20s once again with a light wind resulting in wind chills squarely in the teens with areas across the high elevations of NW NJ and the Poconos in the single digits to around 0.

LONG TERM /MONDAY THROUGH FRIDAY/

High pressure keeps the region dry and cold Monday before shifting offshore Monday night. A weak clipper type system in the Great Lakes could produce some light snow late Monday mainly north of our area. This feature looks weak and moisture starved with any lift to our north.

Come Tuesday into Wednesday, another weak shortwave trough will bring a surface low across the region. Ahead of the low, a warm front will lift across the region, helping boost afternoon temperatures into the 40s Tuesday afternoon and possibly into the 50s on Wednesday! The cold front moves across our area later Wednesday, but will be rather weak. The amount of moisture with this front is uncertain, especially given that the main energy may end up lifting well to our north, thus leaving our region within an area of much weaker forcing. Temperature-wise, the cold front won't be too significant with lows Wednesday night only falling into the 30s, which is still a few degrees above climo.

For Thursday, the flow aloft looks to be more zonal with high pressure sliding across our area. Only a slightly cooler airmass behind the cold front as high temperatures are still forecast to be above average. A shortwave trough ejecting out of the lower Mississippi Valley may weaken as it approaches our region. Some increase in clouds should result along with some very low chances for some rain Thursday night. This system arrives Friday with a continued chance for rain and warm temperatures.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

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

Tonight...VFR. West/northwest winds 5 to 10 kt. High confidence.

Saturday...VFR. A west/northwest around 5 to 10 kt with increasing clouds. High confidence.

Outlook...

Saturday night and Sunday...A period of sub-VFR conditions along with some light snow possible (20-30 percent) Saturday night into early Sunday, otherwise VFR.

Monday and Tuesday...VFR.

Tuesday night into Wednesday night...A period of sub-VFR conditions possible with a weak storm system pushing through.

MARINE

Winds and seas should stay below Small Craft Advisory criteria through Saturday. There is a chance (around 20%) that wind gusts will reach 25 kt through this evening on the Atlantic Coastal Waters adjacent to New Jersey. Due to the low probability of Small Craft Advisory conditions and winds decreasing tonight, no Small Craft Advisory has been issued.

Winds will be out of the NW tonight at 10-15 knots with gusts to 20 knots. Seas of 2-3 feet. On Saturday, winds are out of the NW at 5- 10 knots with seas of 2 feet.

Outlook...

Saturday night through Wednesday...Wind gusts could near 25 knots for a time Sunday into Sunday night, otherwise the conditions are anticipated to be below Small Craft Advisory criteria.

PHI WATCHES/WARNINGS/ADVISORIES

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