textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

A Small Craft Advisory has been issued for all of the Atlantic coastal waters through 6 AM Tuesday.

KEY MESSAGES

1. A weak back door cold front will move through the region this afternoon into early this evening.

2. Monitoring a far offshore low mid-week, but high pressure keeps it dry through the end of the week.

DISCUSSION

KEY MESSAGE 1...A weak back door cold front will move through the region this afternoon into early this evening.

A weak back door cold front will slide southwest through the region this afternoon into early this evening. With onshore flow ahead of it, as well as some mid-level shortwave energy over the area, this may be enough to spark off some light, isolated showers. Have opted to maintain slight chance (around 20%) PoPs for late this afternoon across mainly the eastern half of the area. With that said, the expectation is for most of the region to remain dry, mainly seeing some increased cloud cover and a period of breezy conditions. Generally expect east winds of 10 to 15 mph with some gusts of 20-25 mph, with winds quickly tapering off this evening.

It will be a somewhat chilly night by early June standards, with lows ranging from the mid 40s to low 50s. High temperatures on Tuesday look to be seasonable.

KEY MESSAGE 2...Monitoring a far offshore low mid-week, but high pressure keeps it dry through the end of the week.

By mid-week, the upper-level trough across the Northeast continues to move away and become more amplified. The base of the trough is expected to close off into an upper low. Some guidance has this occurring near the North Carolina coast while others have it more off to the northeast in the Atlantic Ocean as the progression of the upper-level trough is faster. Either way, an upper low is forecast to develop and move off to the northeast. At the surface, a low pressure system will likely form in association with the closed upper low.

Guidance continues to show the surface low pressure system being well off the coast. There will be an expansive area of high pressure that will remain in control across the Great Lakes region and into the rest of the Northeast. As a result, it is increasingly likely that the vast majority of land areas will stay dry with this system. Should the surface low drift closer to the eastern seaboard, we could see a northeasterly flow that could help cool temperatures down slightly mid-week, especially along the coast, but even so, dry conditions will likely still prevail.

Otherwise, we are expecting seasonable temperatures Tuesday with gradual warming through the end of the week. Friday and Saturday could see temperatures in the afternoon creep back into the low 90s as surface high pressure slips to the southeast and ushers in a much warmer airmass across the Northeast. Some precipitation could be possible by the weekend, but confidence remains low at this time.

AVIATION /22Z MONDAY THROUGH SATURDAY/

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

Through 00Z...VFR. There is a slight chance (around 20%) of a few very light showers for KMIV, KACY, and the I-95 terminals, but no restrictions are expected. Northeast wind generally around 10 kt will shift to east through 21-23Z at 10-15 kt. A few gusts around 20 kt are possible. FEW/SCT afternoon clouds around 5-7kft agl. High confidence.

Tonight...VFR. East wind in the evening of 10-15 kt will again become northeast by 05-07Z at 5 kt or less. SCT/BKN mid-level clouds in the evening, with only a few high clouds expected overnight. High confidence.

Tuesday...VFR. Northeast wind in the morning around 5 kt, becoming north-northwest in the afternoon at 5-10 kt. High confidence.

Outlook...

Tuesday night through Saturday...VFR. No significant weather.

MARINE

A Small Craft Advisory has been issued for all of the Atlantic coastal waters through 6 AM Tuesday. East- northeast winds of 15-20 kt and gusts to 25 kt become more northeast tonight at 10-15 kt with gusts around 20 kt. Seas of 4-5 feet through tonight.

By Tuesday afternoon, winds are expected to turn southerly at around 10 kt. Seas around 4 feet.

Outlook...

Tuesday night through Saturday...Sub-SCA conditions probable. Continuing to monitor the far offshore low mid-week for potential changes to the forecast for elevated seas.

Rip Currents...

For Tuesday, northeast winds 10 to 20 mph in the morning will become south or southeast 5 to 10 mph in the afternoon. Breaking waves will be 2 to 4 feet with an easterly swell at 7 to 9 seconds. As a result, there is a HIGH risk for the development of dangerous and life threatening rip currents at Delaware Beaches and a MODERATE risk at the Jersey Shore. A Rip Current Statement has been issued.

For Wednesday, northerly winds 5 to 10 mph early will shift onshore (east to southeast) as the diurnal sea breeze develops. Lessening seas and a moderate period swell will result in a MODERATE risk of rip currents for all of the NJ Shore and DE beaches.

For specific beach forecasts, visit weather.gov/beach/phi

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...High Risk for Rip Currents from 6 AM EDT Tuesday through Tuesday evening for DEZ004. MD...None. MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ450>455.