textproduct: Philadelphia/Mt Holly

SYNOPSIS

An area of low pressure tracks nearby this morning, bringing wintry weather with an arctic front crossing our area. The center of arctic high pressure slides to our south Tuesday before weakening as it shifts offshore Wednesday. A warm front may slide by to our north Wednesday into Thursday, followed by a cold front Thursday night. High pressure returns to close out the week.

NEAR TERM /THROUGH TONIGHT/

Early this morning, snow has overspread most of the region, generally as anticipated, with it taking its time in southern areas as expected. Based on trends with guidance, another modest uptick in snowfall forecast was made, which necessitated the expansion of the Winter Weather Advisory into the Poconos and the Winter Storm Warning into central New Jersey. Areas along the immediate coast and Delaware River may struggle to reach criteria, but most of the region still looks on track for a substantial snowfall.

Snow will linger into the morning in many areas but should be moving out rapidly once it begins to depart, which the area dry by noon or so. With precip lagging a bit, extended northwestern headlines a few hours, but still expect things to end around noon at latest. However, with the arctic front sliding through, gusty northwest winds will develop, resulting in areas of blowing snow. It will be cold with highs in the 20s to low 30s.

Tonight, blowing snow may diminish a little but the wind won't die down a whole lot. What definitely will diminish further will be the wind chills, which will head down towards 0 in many areas, perhaps -10 in the Poconos. Given ongoing winter weather headlines, decided to hold off on a cold weather advisory, but one may definitely be in the cards. Actual lows will be in the single digits in the Poconos to teens most everywhere else. A few snow showers may also make their way into the Poconos late today and tonight with the northwest flow, but their impact should be minimal.

SHORT TERM /MONDAY THROUGH WEDNESDAY/

Our high pressure system moves eastward on Monday which will allow the winds to decrease as the pressure gradient lessens. There is the signal for a piece of upper-level energy to rotate into the region during the second half of Monday into Monday night. Model guidance continues to show the potential for some snow showers Monday afternoon into Monday night. Due to this continued trend, I added a mention of slight chance to chance PoPs (generally 20-40%) for much of eastern PA and northern NJ. The high pressure system could still suppress this activity to the north which is why PoPs were capped at chance. Regardless, we do see more cloud cover filter in through the day due to that piece of upper-level energy moving through. Highs on Monday are in the upper 20s to low 30s for most with the higher elevations in the mid 20s.

Monday night is another cold night with temperatures in the teens for many. Winds will be lower Monday night at around 10-15 mph which results in wind chill values in the single digits to low teens for most. For Tuesday, it is a dry day with the high pressure system in place across the region. Highs on Tuesday are in the mid 20s to mid 30s.

By Tuesday night, temperatures are slightly higher with overnight lows in the 20s for most and teens for the higher elevations. Winds are at around 5-10 mph, so wind chill values are in the teens and low 20s for most.

Our weather pattern starts to change by Wednesday which results in more mild air filtering in. Our high pressure system starts to move offshore Wednesday which gives us more of a southwest wind that ushers in warmer air. Highs on Wednesday are mainly in the upper 30s to upper 40s.

LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/

A more amplified pattern looks to take shape for the end of the week. A low pressure system near the Great Lakes region Thursday moves northeast into Quebec Friday. This low pressure system will drag a cold front through the area Thursday night. The precipitation type with this cold front will be rain as temperatures will be mainly in the mid 40s to mid 50s on Thursday and mainly upper 30s to mid 40s Thursday night. By Friday, a high pressure system builds in from the west and temperatures are in the 40s for most. This high pressure system moves closer to the region Saturday which may keep us completely dry. However, there is a low pressure system near the Great Lakes region and its associated warm front extending close to the area during this timeframe that may have the potential to initiate some precipitation. Due to the uncertainty, PoPs are capped at a slight chance for Saturday.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

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

Today...Widespread IFR/LIFR with occasional VLIFR conditions in the morning, followed by improvement with snow ending. Expect conditions to lift to VFR by midday at all terminals as precipitation ends from northwest to southeast. Northwest winds around 10-15 kt with gusts up to 25-30 kt in the afternoon. This may result in some blowing snow which could reduce vsby at times by afternoon, but low confidence on this so kept out of TAFs. Moderate confidence overall.

Tonight...VFR with continued gusty northwest winds 10-15 kts with gusts 20-25 kts. High confidence.

Outlook...

Monday...VFR. West-northwest winds gusting up to 20 knots. Slight chance to chance (20-30%) of a snow shower at KABE/KRDG.

Monday night through Wednesday night...VFR. No significant weather.

Thursday...Primarily VFR. A slight chance of rain showers in the afternoon.

MARINE

Rain changing to snow early, then ending towards midday, with winds picking up quickly beginning after daybreak, ramping up to gale- force by the afternoon and evening, continuing into the overnight hours. Gale Warnings are in effect for through tonight. Areas of freezing spray also possible late today and tonight.

Outlook...

Monday...Gale-force wind gusts early in the morning with a period of Small Craft Advisory conditions afterward. Areas of freezing spray possible during the morning.

Monday night through Tuesday night...No marine headlines are currently anticipated with winds remaining below 25 kt and seas below 5 feet.

Wednesday...Small Craft Advisory conditions possible with southwesterly winds 15-20 kt with gusts perhaps near 25 kt. Seas 2-4 feet.

Wednesday night...No marine headlines are currently anticipated with winds remaining below 25 kt and seas below 5 feet.

Thursday...Small Craft Advisory conditions possible with south- southeasterly winds 15-20 kt with gusts perhaps near 25 kt. Seas 4-6 feet.

PHI WATCHES/WARNINGS/ADVISORIES

PA...Winter Weather Advisory until 1 PM EST this afternoon for PAZ103-105. Winter Weather Advisory until 10 AM EST this morning for PAZ054-055-060>062. Winter Storm Warning until 1 PM EST this afternoon for PAZ070- 071-101-102-104-106. NJ...Winter Weather Advisory until 1 PM EST this afternoon for NJZ009-010-016-021>025. Winter Weather Advisory until 10 AM EST this morning for NJZ001-007-008. Winter Storm Warning until 1 PM EST this afternoon for NJZ012>015-017>020-026-027. DE...Winter Weather Advisory until 1 PM EST this afternoon for DEZ001>004. MD...Winter Weather Advisory until 1 PM EST this afternoon for MDZ012-015-019-020. MARINE...Gale Warning until 7 AM EST Monday for ANZ430-431-453>455. Gale Warning from 11 AM this morning to 7 AM EST Monday for ANZ450>452.