textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

The Severe Thunderstorm Watch was allowed to expire at 10 PM and we've also cancelled the Flood Watch.

KEY MESSAGES

1) The threat for severe weather and flash flooding has largely ended for tonight, however some additional severe storms and flash flooding will be possible Wednesday. Wednesday's severe weather and flooding threat is not expected to be as widespread though as it will be confined mainly to areas south and east of the urban corridor.

DISCUSSION

KEY MESSAGE 1...The threat for severe weather and flash flooding has largely ended for tonight, however some additional severe storms and flash flooding will be possible Wednesday. Wednesday's severe weather and flooding threat is not expected to be as widespread though as it will be confined mainly to areas south and east of the urban corridor.

As of 10 PM, the Severe Thunderstorm Watch has been allowed to expire and we've also cancelled the Flood Watch. That said, the area still remains in the warm sector ahead of an approaching cold front and though the instability has significantly decreased, there is still some remaining. For this reason, still expecting some showers and a few storms to continue into the overnight as the cold front approaches from the north and west and weak impulses aloft move through the upper level flow. Locally heavy downpours will be possible but any flooding should be largely of the nuisance variety.

On Wednesday, the cold front will sag farther south and east and depending on how quickly this clears our area there will be some showers and thunderstorms, especially as additional shortwaves move through the flow within the upper-level trough overhead. This looks to be more concentrated across southern New Jersey to Delmarva but could extend into the I-95 corridor for a time. There is some severe weather risk mainly south/east of the I-95 corridor with locally damaging wind gusts the main threat. The greater instability and shear looks to reside across Delmarva on southward, where a little higher severe thunderstorm risk is indicated. Some locally excessive rainfall is possible with some local flash flood risk, however this looks to be less compared to today given the shift farther south and more into the coastal plain. Once the front moves away by later Wednesday, it turns drier for Thursday/Friday and right into the weekend.

AVIATION /02Z WEDNESDAY THROUGH SUNDAY/

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

Tonight...Still some showers and thunderstorms around this evening mainly from around Philly southward. In any of these showers conditions may still drop to MVFR or even IFR...best chances for this at MIV and ACY. Otherwise, widespread showers diminish by the overnight period with MVFR cigs likely affecting most sites by around the 04-07z time frame. Winds generally southwest 10 to 15 knots but locally strong and variable winds possible in any storms.

Wednesday...Once morning clouds clear by around 14Z, should have prevailing VFR conditions. However, temporary MVFR or even IFR conditions will be possible with showers and storms. The highest risk of showers and storms is at KACY, but it is possible the storms will be south of all TAF sites. Southwest winds around 10 KT with some gusts of 15-20 knots possible. Moderate confidence.

Outlook...

Thursday through Saturday...VFR.

MARINE

Small Craft Advisory conditions for all coastal waters through Wednesday evening. SCA conditions do subside though overnight on Delaware Bay. Gusty thunderstorms probable into tonight.

Outlook...

Wednesday...Small Craft Advisory remains in effect for the ocean zones.

Thursday through Saturday...The conditions are anticipated to be below Small Craft Advisory criteria.

Rip Currents...

For Wednesday, winds turn more southwesterly but still 10-20 mph. However, breaking wave heights are expected to increase, with breaking waves in the surf zone as high as 5 feet possible. Still a 7 second period though which will mitigate the rip current threat some. However, will continue with a MODERATE risk for the development of dangerous rip currents at all beaches.

For Thursday, winds come around to the northeast and will generally be 15 to 20 mph. Breaking waves are expected to be around 2-4 feet with a 7 second period. With the onshore component of the wind and multiple swell groups expected, expecting a MODERATE risk for the development of dangerous rip currents at all beaches.

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

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ430-431. Small Craft Advisory until 2 AM EDT Thursday for ANZ450>455.