textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

No significant changes.

KEY MESSAGES

1. Several cold fronts and waves of low pressure will impact the region through next week.

DISCUSSION

KEY MESSAGE 1...Several cold fronts and waves of low pressure will impact the region through next week.

High pressure offshore and a few weak upper systems will bring a few showers this evening (mainly across the northern counties) and then a better chance on Saturday for all areas. An afternoon tstm is possible too. The latest SPC outlook for Saturday indicates that a marginal risk for severe tstms exists across the southern half of the CWA. Rainfall amounts of 1/4 to 1/2 inch are possible but up to an inch possible in any tstm.

Weak high pressure passes through the region Sunday morning, and at least the start of the day and into early afternoon should be partly to mostly sunny and mild with highs in the 70s to low 80s. Some shortwave energy ahead of a cold front approaches from the west in the afternoon and may spark off some showers and isolated thunderstorms mostly north and west of Philadelphia.

That cold front then slowly works its way through the region Sunday night and Monday, and low pressure over the Southeast and lifts towards the Mid-Atlantic and Northeast during this time, and departs Monday afternoon. A widespread beneficial and soaking rain will fall during this time with 1/2 to 1 inch of rain throughout.

A, relatively speaking for this time of year, chilly airmass will spread into the region with higher in the mid to upper 60s for most of next week. The nest chance for rain arrives on Wednesday with the next low pressure system.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

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

Tonight...VFR expected. Mostly mid-level clouds overnight most areas. A few scattered showers for northern areas KRDG/KABE into the early evening. West to Southwest winds 10 to 15 kts with gusts to 25 kts then decreasing after sunset. Medium/High confid.

Saturday...VFR early then lowering CIGs as rain showers arrive during the morning from West to East across the terminals. A TSTM is possible during the afternoon. Winds will be South to Southwest at around 10 to 15 kts much of the time. Medium confid.

Outlook...

Saturday night...Sub-VFR in fog and low stratus likely.

Sunday...VFR most of the day. Sub-VFR in scattered SHRA possible at KRDG/KABE in the afternoon.

Sunday night through Monday...Sub-VFR in SHRA and isolated TSRA. Improving conditions possible late Monday.

Tuesday...VFR. NSW.

Wednesday...Sub-VFR possible in SHRA.

MARINE

A Small Craft Advisory is in effect for most of the ocean zones and the lower Delaware Bay for tonight and into Saturday. Winds should become gusty with 20 to 25 kts across those areas into the evening then a relaxing of winds late tonight before they become gusty again Saturday. Winds up across the northern-most NJ zone and upper Delaware Bay will be gusty too, but speeds closer to 20 kts expected in those spots. Scattered showers this evening across the NJ waters then more numerous showers and a chance for a tstm Saturday into Saturday evening.

Outlook...

Saturday night through Wednesday...Lingering SCA conditions Saturday evening, then generally sub-SCA conditions into next week with brief chances possible Monday and Wednesday. Visibility restrictions in showers and possible thunderstorms Sunday night through Monday and again on Wednesday.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until midnight EDT Saturday night for ANZ431-451>455. Small Craft Advisory from 10 AM Saturday to midnight EDT Saturday night for ANZ450.