textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

No significant changes.

KEY MESSAGES

1. Following a period of seasonable conditions today, above normal temperatures take over this weekend. High temperatures will climb into the mid 80s to low 90s beginning Sunday through the middle of next week.

2. A cold front will bring chances of showers and thunderstorms to the region late Wednesday through Thursday, along with moderating temperatures closer to normal by the end of next week.

DISCUSSION

KEY MESSAGE 1...Following a period of seasonable conditions today, above normal temperatures take over this weekend. High temperatures will climb into the mid 80s to low 90s beginning Sunday through the middle of next week.

An upper low pressure area remain across the area today but moves away tonight. Surface high pressure builds in later tonight. These systems will keep skies mostly cloudy this morning then more sunshine expected later this afternoon. It'll remain seasonably cool with highs in the upper 60s to low 70s across the area. Winds will be Northwest at 10 to 15 mph with some gusts 20 to 25 mph.

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 south to southwesterly flow for several days and gradually warming temperatures from Saturday through Tuesday or Wednesday.

Saturday will feature highs mainly in the upper 70s to low 80s with highs Sunday getting into the mid to upper 80s inland. Along the immediate coast it will generally be a good 5-10 degrees cooler.

Temperatures continue to climb for Monday with mid to upper 80s for many areas, and low 90s over portions of eastern PA, inland southern NJ, and Delmarva. Tuesday and potentially Wednesday could see some areas inland getting into the mid 90s but confidence on specific details becomes a bit lower by this time. The heat looks to break by Thursday. In terms of overall heat impacts, the current forecast has the urban corridor flirting with heat advisory criteria by next Tuesday into Wednesday, but that said, this particular setup doesn't look exceptionally favorable for both very high heat and humidity. Through Tuesday, mixing should keep dewpoints from getting too high. Evapotranspiration will be limited due to ongoing drought and ocean temperatures remain cool. Long story short, it is still quite early in the season for high dewpoints to combine with high heat. By the time these numbers creep up by Wednesday, clouds and showers/storms may help knock temperatures down some. In any case, we'll be getting close to record high temperature territory Monday through Wednesday of next week.

Temperatures will moderate closer to normal by late next week following a cold frontal passage late Wednesday.

KEY MESSAGE 2...A cold front will bring chances of showers and thunderstorms to the region late Wednesday through Thursday, along with moderating temperatures closer to normal by the end of next week.

Overall, the next 5 days look mostly dry, but can't rule out some diurnally driven showers/thunderstorms, mainly on Sunday. PoPs Sunday are mainly 10-20% as forcing looks weak and mid levels are dry. Could see some isolated convection focused near surface forcing mechanisms, such as higher terrain and the sea breeze. Surface flow will be westerly inland, but southerly near the coast, so this convergence zone could be something to help convection initiate. We will have a better idea once we get into range of the CAMs.

As mentioned earlier, a cold front will approach and likely bring an end to the stretch of above normal temperatures by late next Wednesday. Convective activity will likely accompany that front in some form or fashion, but it's too early to speculate on specific impacts or hazards. The front could linger nearby into Thursday bringing additional showers.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

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

Thru 12Z... VFR. BKN or OVC low/mid level clouds across the area. Northwest winds 5 to 10 knots. High confid.

Today... VFR. Mostly BKN low/mid level clouds continue. They may thin some Delmarva/SE NJ this afternoon. Northwest winds 10 to 12 knots with gusts 20 to 24 kts after mid-morning. Medium/high confid.

Tonight... VFR. Winds becoming light from the West to Northwest. High confid.

Outlook...

Saturday through Tuesday...VFR prevailing with no significant weather expected. 10-20% chance of a shower or storm on Sunday.

MARINE

Winds and seas look to remain below SCA levels today and tonight. Fair weather is expected with seas on the ocean mostly 3 to 4 ft.

Outlook...

Saturday through Sunday...A period of Small Craft Advisory conditions is likely (60 % chance) late Saturday into Saturday night as southwest winds increase to around 15 to 20 gusting 20 to 25 knots. 20% chance of an isolated thunderstorm nearshore on Sunday.

Monday through Tuesday...No marine hazards expected. Fair weather.

Rip Currents...

The rip current forecast for both Delaware and New Jersey is moderate today.

While there is an onshore 3-4 feet/10-11 second period swell over the ocean, there is also an offshore wind today around 10-15 knots. This should counter act each other and lead to a moderate risk of rip currents today.

The rip current forecast for both Delaware and New Jersey is moderate on Saturday.

There will continue to be an onshore 3-4 feet/10-11 second period swell over the ocean, but winds will shift to more southwesterly and increase in speed late in the day around 10-15 knots. While the forecast is moderate for Saturday, we will continue to monitor the forecast in case we need to upgrade to high.

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

PHI WATCHES/WARNINGS/ADVISORIES

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