textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Small Craft Advisories have been cancelled. Updated Aviation discussion for the 06Z TAFs. Updated near term Key message.

KEY MESSAGES

1. A slow moving front and an upper low pressure system will continue across the area today and tonight.

2. Above normal temperatures take over beginning this weekend, with temperatures potentially climbing towards the low 90s next week.

DISCUSSION

KEY MESSAGE 1...A slow moving front and an upper low pressure system will continue across the area today and tonight.

A cold front which cross the area overnight will linger near the shore this morning before moving offshore later. An upper low pressure system from the Great Lakes will develop south/east across our region through the day. This will keep unsettled conditions for our area with more clouds than sun today and a few showers around.

The lingering showers early in the day will be mostly near the coast with some additional scattered showers developing in the afternoon over portions of NE PA and northern NJ due to the upper level low. It will be cooler with considerable clouds around and highs generally in the 60s.

KEY MESSAGE 2...Above normal temperatures take over beginning this weekend, with temperatures potentially climbing towards the low 90s next week.

An upper level ridge builds into the Eastern US this weekend and into next week, bringing a period of above normal and summer-like temperatures. At the surface, high pressure over the western Atlantic anchors off the coast of the Mid Atlantic. This will result in a warm southerly flow for several days and gradually warming temperatures from Saturday through Tuesday or Wednesday. Given the NBM has been running a bit warm lately, temperatures were lowered slightly Sunday through Tuesday as most of the deterministic guidance has highs a few degrees lower than what the newest NBM had.

Regardless, it will be quite warm in the extended to borderline hot. Saturday will feature upper 70s to low 80s, with Sunday getting into the low to mid 80s. Temperatures continue to climb for Monday with mid to upper 80s and an outside shot at 90. Tuesday looks to be the warmest day of the stretch with upper 80s and low 90s currently anticipated. Tuesday could flirt with Heat Advisory criteria for the I-95 corridor and adjacent counties, where the current threshold through June is a heat index of 96 degrees F or higher, however this is looking less probable as of this morning's update. The heat looks to break either Wednesday or Thursday, dependent on how quickly a cold front comes in during the middle of the week.

Overall this stretch looks mostly dry. Guidance is now trying to hint at some diurnally driven showers/thunderstorms though, mainly on Sunday as a shortwave passes by to the north. Don't have more than 15-20% PoPs in though as forcing looks weak but we will have a better idea once we get into range of the CAMs.

As mentioned earlier, sometime Wednesday-Thursday of next week, a cold front will approach and likely bring an end to the stretch of above normal temperatures. Convective activity will likely accompany that front in some form or fashion, but it's too early to speculate on specific impacts or hazards.

AVIATION /08Z THURSDAY THROUGH MONDAY/

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

Thru 12Z... Mostly VFR but MVFR is possible across NJ as the slow moving area of showers continues. Light and variable winds mostly. Medium confid.

Today...VFR BKN sky conditions most areas thru the day. There may be some lingering MVFR early for KACY/KMIV. Also, clouds and light showers possible for North NJ and into the Poconos this morning. Winds will increase after daybreak and eventually become West to Northwest at 10 to 15 kts with gusts to 25 kts. Medium confid.

Tonight... VFR expected. BKN clouds early then SCT clouds overnight. West to Northwest winds 5 to 10 knots. Medium/high confid.

Outlook...

Friday through Monday...VFR conditions with no significant weather expected. 10-20% chance of a shower or storm on Sunday.

MARINE

A slow moving front and weak low pressure will be across the waters through Thursday. Winds and seas have decreased overnight and will remain below Small Craft Advisory conditions. Winds will turn more West to Northwest this morning and a few gusts 15 to 20 kts are possible. Seas on the ocean will be 3 to 4 ft much of the time. Showers will continue thru the morning but then diminish this afternoon.

Outlook...

Friday...Chance (20-30%) of SCA conditions on the ocean waters as seas could near 5 feet.

Friday Night through Monday...Sub-SCA conditions expected.

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...None.