textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Updated aviation section for 18z TAFs. Minor changes for long range forecast.

KEY MESSAGES

1. There is a limited risk for fire weather conditions for the rest of today.

2. A few systems bring showers to the area Wednesday into Thursday. Another weak system could bring some showers on Saturday.

DISCUSSION

KEY MESSAGE 1...There is a limited risk for fire weather conditions for the rest of today.

A breezy pattern has developed across the area as of the early afternoon. South to SouthWest winds will continue generally around 15 to 20 mph gusting 25 to 30 mph. Meanwhile, the relative humidity during peak heating will be around 25%-35% for many areas. Fuel moisture will also decrease with significant heating and a gusty breeze, although surface dew points should be higher than Monday. Full green-up has occurred in much of our area however based on collaboration with our State Fire Partners we've issued an SPS earlier for fire weather for most of southern NJ and DE (excluding coastal strip).

KEY MESSAGE 2...A few systems bring showers to the area Wednesday into Thursday. Another weak system could bring some showers on Saturday.

An area of low pressure well to the north in Canada will drag a cold front through the Great Lakes and move towards our region tonight. Showers begin to move in Wednesday morning but the bulk of the rain comes through later Wednesday which is a bit slower then previous fcsts. The front tries to move through but will eventually stall out near or just east of our area. Another area of low pressure will develop over the southeast and lift towards the Mid-Atlantic coast along the stalled front. The pops across Delmarva and southern NJ will tail off slower and remain in the chance to low likely range Thursday before decreasing Thursday night. There is a trend towards lower Pops for the N/W areas from what was forecasted earlier. Overall, QPF is a little higher than previous fcsts with around 1/2 inch for the southern areas and 3/4 inch for the southern Poconos.

While some guidance still attempted to bring some convective elements to the region, the consensus is that we will see low instability and limited to zero severe/flooding threat. Overall, this will be more beneficial rain for the area with an isolated thunderstorm possible.

For Saturday, a weak area of low pressure will move into the region, potentially producing some showers. This appears to be nothing more than a potential weekend spoiler with no significant impacts expected at this time. Pops range from the 50%-60% range for the Poconos down to 35 to 40% for south Delaware and SE New Jersey.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

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

Rest of today... VFR. Few clouds, South to Southwest winds 10 to 15 kts with gusts 25 kts. High confid.

Tonight... VFR expected. Gusty south/southwest winds gradually diminishing through the evening. Low-end LLWS possible KABE/KRDG and close to the shore. Moderate confidence.

Wednesday... VFR early then lowering CIGS and showers arrive West to East. Low-end MVFR probable but IFR possible 14Z/16Z N/W and 18Z/20Z S/E. Medium confid overall.

Outlook...

Wednesday night through Thursday...MVFR/IFR conditions with showers, especially Wednesday midday into the afternoon and then a second round on Thursday daytime S/E. KRDG/KABE may not see any showers on Thursday and things have continued the previous trend for precip being further east away from the I-95 corridor for Thursday. An isolated thunderstorm possible. South to Southwest winds becoming West overnight .

Thursday night through Friday Night...VFR. No significant weather.

Saturday...Sub-VFR conditions possible (30-50%) with some showers and potential low clouds moving in.

Sunday... VFR expected.

MARINE

For the ocean waters, a Small Craft Advisory went up earlier and will remain in effect for tonight and into Wednesday night. Winds will gust 25 to 30 kts and seas will continue to build reaching 4 to 7 ft. Fair tonight and into Wednesday morning, then showers for Wed afternoon into Thursday.

Across Delaware Bay, winds continue a bit below SCA levels presently, but should eventually reach 25 kts and a moderate chop by the evening. The SCA flag will continue until 2AM. Fair tonight and into Wednesday morning, then showers for Wed afternoon into Thursday.

Outlook...

Thursday through Saturday...No marine headlines expected.

PHI WATCHES/WARNINGS/ADVISORIES

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