textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

The Small Craft Advisory for coastal waters north of Cape May is no longer in effect. There are no headlines over the marine zones at this time.

KEY MESSAGES

1. Low pressure slides south of the region Thursday and Thursday night, bringing a chance for rain and snow.

2. A cold frontal passage on Saturday night may bring some snow showers to northern areas.

3. Uncertainty persists with regards to an area of low pressure that may move into the region early next week producing another chance of wintry weather.

DISCUSSION

KEY MESSAGE 1...Low pressure slides south of the region Thursday and Thursday night, bringing a chance for rain and snow.

A wave of low pressure will pass west-to-east south of the region Thursday into Thursday night. This will provide another opportunity for some wintry weather, though impacts are expected to be limited. Latest guidance continues to keep the system mostly south, lessening the risk of a significant intersection of colder air and precipitation and limiting the potential for impactful snow. We continue to maintain a slight chance to chance POPs for snow across our northern tier Thursday into Thursday night, with chance POPs of rain/snow mix across a central slice of the CWA including Philadelphia. Further south, we do have some likely POPs, but temps look warm enough for plain rain across the Delmarva and far southern NJ. We'll continue to monitor, but at this time this mainly looks like a sub advisory event should it occur, and its possible little or no wintry precip occurs. The official snowfall forecast retains no actual snowfall, given the low probability of any occurring.

KEY MESSAGE 2...A cold frontal passage late Saturday night may bring some snow showers to northern areas.

High pressure will be in control Friday into Saturday welcoming the return of dry and milder weather as a warm front lifts well north of the area. Highs will mainly be in the low 40s to low 50s on Friday with highs in the upper 40s to upper 50s on Saturday. This will likely melt much of the existing snow pack.

By Saturday night, the warmth will come to an end, as an arctic cold front will be tracking across the region. As of now, guidance suggests that this front should be relatively moisture starved, however some guidance depicts a weak wave of low pressure riding along it. This may result in a period of light snow north and west, primarily north of the I-78 corridor late Saturday night into Sunday morning. Any accumulations would be negligible, with cooler temperatures returning for Sunday.

KEY MESSAGE 3...Uncertainty persists with regards to an area of low pressure that may move into the region early next week producing another chance of wintry weather.

With fresh cold air in place behind arctic front, more wintry weather is possible for the early portions of next week. Unfortunately it's too early to know for sure with regards to timing as forecast guidance continues to have trouble with the handling of upper level features. However, latest NBM probabilities suggest that a 50-70% chance of measurable snowfall is in the realm of possibility sometime between Monday and Tuesday. More details to come in the coming days once guidance comes into better agreement. Beyond Tuesday, guidance then suggests a warm up is likely by the middle of next week. Any systems in this time period will most likely be in the form of rain.

AVIATION /12Z THURSDAY THROUGH MONDAY/

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

Thursday...Generally VFR, but MVFR or lower conds possible, mostly at KMIV/KACY after 18Z. Sub-VFR conds may stretch as far north as KTTN, but confidence is low in that happening. NW winds, becoming N or even NE at 5 to 10 kt. Low confidence on sub-VFR conds.

Thursday night...Sub-VFR visibilities possible across the southern terminals KMIV/KACY due to patchy fog. Winds light and variable. Low confidence in fog development.

Outlook...

Friday through Sunday...VFR. A chance for light snow near KRDG and KABE late Saturday night. Gusty NW winds up to 20 kt possible on Sunday. Otherwise, no significant weather expected.

Sunday night through Monday...Primarily VFR, however sub-VFR conditions are possible with a chance of light snow on Monday.

MARINE

The Small Craft Advisory for coastal waters north of Cape May is no longer in effect. Winds from the northwest around 10 kts shift to the northeast in the afternoon. Seas 2-4 feet.

Outlook...

Friday through Sunday...No marine headlines expected. Winds will generally remain less than 15 kt through Saturday and up to 20 kt on Sunday. Seas of 2-3 feet. Fair weather.

Sunday night through Monday...SCA conditions possible with wind gusts up to 25 kt and seas up to 5 feet. Light snow possible on Monday.

PHI WATCHES/WARNINGS/ADVISORIES

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