textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Aviation section updated for the 12Z TAFs.

KEY MESSAGES

1. A strong mid-level disturbance will pass through the region this afternoon with minimal impacts.

2. High pressure keeps the area dry through the end of the week.

DISCUSSION

KEY MESSAGE 1...A strong mid-level disturbance will pass through the region this afternoon with minimal impacts.

A weak cold front, more like a dry line and a wind shift, has passed through the region as noted by winds having shifted to more of a north to northeast flow and dew points have begun to drop into the low to mid 40s. Dew points will drop further by this afternoon as that northerly flow increases.

Another mild day on tap with highs in the mid and upper 70s. Late afternoon sea breezes will develop, and there may be a noticeable drop in temperatures behind it, especially near the coasts.

A strong mid-level shortwave will pass through the region this afternoon. While it will be hard to overcome the dry air at the surface, cannot rule out a spot shower here and there, generally north and west of Philadelphia. Any QPF will be minimal, at best. PoPs will be capped at 20 percent, or slight chance.

Warmer tonight with lows in the mid and upper 50s.

KEY MESSAGE 2...High pressure keeps the area 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. Recent guidance shows more agreement on this occurring near the North Carolina coast. As the upper low develops, it will 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, the forecast continues to remain dry through the end of the week.

A gradual warming trend will take place this week with temperatures potentially reaching into the low 90s by Friday and Saturday for some locations. As our surface high pressure system slips to the southeast, it will usher in a much warmer airmass across the Northeast Friday into Saturday. In terms of any precipitation, there is some possible this weekend, particularly Saturday night into Sunday, but confidence remains low at this time.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

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

Today...VFR. N winds 5 to 10 kt. Sea breezes at KMIV and KACY will turn winds to the SE, then S, after 18Z. High confidence.

Tonight...VFR. N to NW winds 5 kt or less. High confidence.

Outlook...

Wednesday through Saturday...VFR. No significant weather.

MARINE

Seas will remain elevated at around 5 feet south of Cape May. The SCA continues from Cape May to Fenwick Island until noon.

Sub-SCA conditions thereafter. East winds 10 to 15 kt with gusts up to 20 kt will turn north after sunrise, then will become southeast 5 to 10 kt late this afternoon. Winds become west around 10 kt tonight with 3 to 4 feet seas.

Outlook...

Wednesday 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...

Today, east winds 10 to 15 mph with gusts up to 20 mph will diminish to 5 to 10 mph late this morning, then will turn southeast, then south, by late afternoon. Breaking waves will be 2 to 3 feet at the Jersey Shore and 3 to 4 feet at Delaware Beaches. There will also be an easterly swell with a 6 to 8 second period. 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 remains in effect for Delaware Beaches.

On Wednesday, north winds 5 to 10 mph in the morning will turn to the east, then southeast late in the day behind sea breezes. Breaking waves will be 2 to 3 feet. There will be a lessening easterly swell with a 9 to 10 second period. As a result, there is a LOW risk for the development of dangerous and life threatening rip currents for the Jersey Shore for Monmouth county, Ocean county, and Atlantic county, and a MODERATE risk for the Jersey Shore for Cape May county and Delaware Beaches.

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

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...High Risk for Rip Currents through this evening for DEZ004. MD...None. MARINE...Small Craft Advisory until noon EDT today for ANZ454-455.