textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

The Small Craft Advisory has been expanded to now include all of the Atlantic coastal waters.

KEY MESSAGES

1. Showers are expected to impact portions of the region Sunday and Sunday night.

2. Canadian high pressure will bring much cooler temperatures and dry weather through much of the week.

DISCUSSION

KEY MESSAGE 1...Showers are expected to impact portions of the region Sunday and Sunday night.

Low pressure developing along the stalled frontal boundary to our south Sunday and Sunday night will provide another round of showers across portions of the region. The timing of the showers will be focused during the afternoon hours Sunday, but could begin near/south of Philly in the morning and linger area wide into the evening or overnight hours. PoPs have retreated slightly and now range from around 40-50% along and north of I-80 to around 50-60% within the I-95 corridor and Philly metro, to 60-70% across Delmarva and far southern New Jersey. The latest QPF forecast has around 0.10" or less along the I-95 corridor and points north and west with around 0.25-0.75" across the southern Delmarva and far southern New Jersey. It's possible the showers don't make it much farther northwest than the I-95 corridor. There still remains spread in the guidance as to exactly how far north and west the showers will make it.

Given overcast skies, easterly winds, and showers, temperatures Sunday will be cooler with highs likely only reaching the low to mid 60s in many areas.

KEY MESSAGE 2...Canadian high pressure will bring much cooler temperatures and dry weather through much of the week.

Canadian high pressure and a much cooler air mass will build into the region starting on Monday. Monday will feature mostly sunny skies with highs within a few degrees of 70, though a stiff northwest breeze will make it feel cooler. Sunny skies continue on Tuesday, though highs will only be in the upper 50s to mid 60s for much of the region which is upwards of 10 degrees below normal. Lows will fall mainly into the 40s, with 50s along the coast and the upper 30s in the Poconos. Some areas of frost will be possible mainly north of I-78 late Tuesday night into Wednesday morning.

As cold advection wanes by mid-week, the airmass will begin to modify and trend warmer as southerly flow returns. Highs remain in the 60s on Wednesday, before warming back into the 70s again for Thursday and Friday. With high pressure remaining in control, mostly clear skies and dry weather is expected through the end of the week.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

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

Tonight...Mainly VFR but patchy rural fog possible. MVFR ceilings may arrive prior to daybreak across ILG/MIV/ACY. Winds remain out of the ENE to east at 5-10 knots. Moderate confidence.

Sunday...Widespread MVFR cigs during the morning with IFR or lower cigs during the afternoon into the evening. Scattered showers move in through the morning into the early afternoon. Shower coverage lessens during the evening hours. Winds continue out of the ENE to east at 5-10 knots. Moderate confidence.

Outlook...

Sunday night...Sub-VFR conditions possible with a slight chance of showers and patchy fog overnight.

Monday through Thursday...VFR. Other than some gusty winds possible on Monday, no significant weather expected.

MARINE

The Small Craft Advisory has been expanded to now include all of the Atlantic coastal waters for 5 foot seas and wind gusts up to 25 kts. NE winds around 15 kts with gusts up to 25 kts.

Outlook...

Sunday night...Lingering SCA conditions due to seas around 5 feet early, before abating overnight.

Monday through Monday night...No marine headlines expected, although a few gusts up to 25 kt possible.

Tuesday through Thursday...No marine headlines anticipated.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory from 2 AM Sunday to 2 AM EDT Monday for ANZ450. Small Craft Advisory until 2 AM EDT Monday for ANZ451>455.