textproduct: Philadelphia/Mt Holly

WHAT HAS CHANGED

Small Craft Advisory taken down for Delaware Bay. Minor updates to Near term forecast. Aviation discussion updated.

KEY MESSAGES

1. Potentially record breaking warmth is possible this week with very warm and above normal temperatures continuing through the upcoming weekend.

DISCUSSION

KEY MESSAGE 1...Potentially record breaking warmth is possible this week with very warm and above normal temperatures continuing through the upcoming weekend.

A significant warm up is expected to continue through the week and into the upcoming weekend with the potential for record breaking temperatures.

With high pressure situated over the Atlantic Ocean and the warm front well north of the Mid-Atlantic region, continued warmth is expected. Very warm air aloft coupled with warm air at surface levels will allow temperatures to be as much as 15 to 30 degrees above average this week. As of now, forecast highs are in the low to mid 80s on Tuesday with mid/upper 80s to low 90s on both Wednesday and Thursday, though Thursday may be a touch cooler due to more cloud cover. See Climate Section below regarding potential record breaking temperatures.

If temperatures touch 90F, it would be the first 90 degree day of the year and first since early September. As is typical in spring though, temperatures along and near the coast will be significantly cooler due to the colder sea surface temperatures and diurnal sea breeze. While a weak surface front passes through late Thursday night into Friday morning, temperatures will stay well above normal through the weekend with temps mainly in the mid 70s to mid 80s.

Not only will it be very warm over the course of the week, but it will also remain mainly dry. This is of elevated concern for ongoing drought/abnormally dry conditions over much of the area, which will likely only get worse after this week. A few weak disturbances will pass by to the north through Thursday, but other than a stray shower or thunderstorm each afternoon north of the I-78 corridor, no significant rainfall is expected. Flow will generally be out of the southwest, which is more favorable in terms of moisture, which likely will hinder the fire weather concerns this week. Winds will generally be light as well, as another limiting factor. So, even though it will be warm and dry, fire weather concerns are minimal.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

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

Tonight...Primarily VFR. Southwest winds around 5-10 kts decreasing to around 5 knots or less late in the overnight hours. A few showers KRDG/KABE thru midnight with VCSH in the TAFs. Medium/High confidence.

Tuesday...Prevailing VFR. Southwesterly winds around 10 kts with gusts of 15-20 kts in the afternoon. High confidence.

Outlook...

Tuesday night...VFR. No significant weather expected.

Wednesday through Thursday night...Prevailing VFR. A chance of showers and thunderstorms (~20-40%) in the afternoon and evening hours each day for the Lehigh Valley and I-95 terminals.

Friday through Saturday...VFR. A few showers possible, otherwise no significant weather.

MARINE

Small Craft Advisory continues for the Ocean zones until 1AM Tuesday. Southwest wind gusts of 25-30 kts will persist through late afternoon and early evening hours. Seas of 4-6 feet will gradually diminish tonight, falling below 5 feet after midnight. Sub-SCA conditions expected for Tuesday. Southwest winds will gust to around 15-20 kts in the afternoon with seas around 2-4 feet.

Outlook...

Tuesday night through Saturday...No marine headlines expected. Winds will generally remain below 20 kt with seas around 2-4 feet. A few showers possible, otherwise fair weather.

CLIMATE

Warm temperatures well above normal are expected for the upcoming week. Wednesday is currently projected to be the warmest day, though Tuesday through Thursday could see some records broken depending on the site. Below are record highs and record high minimum temperatures for April 14th through April 16th.

Record High Temperatures April 14 Site Record/Year Allentown (ABE) 88/2023 AC Airport (ACY) 86/1945 AC Marina (55N) 90/1941 Georgetown (GED) 87/1977 Mount Pocono (MPO) 84/2023 Philadelphia (PHL) 91/1941 Reading (RDG) 90/1941 Trenton (TTN) 89/1941 Wilmington (ILG) 87/1941

Record Warmest Low Temperatures April 14 Site Record/Year Allentown (ABE) 61/2014 AC Airport (ACY) 63/2023 AC Marina (55N) 60/2023 Georgetown (GED) 65/2019 Mount Pocono (MPO) 56/2014 Philadelphia (PHL) 62/2014 Reading (RDG) 64/2014 Trenton (TTN) 62/2014 Wilmington (ILG) 60/2014

Record High Temperatures April 15 Site Record/Year Allentown (ABE) 86/1941 & 1994 AC Airport (ACY) 90/1967 AC Marina (55N) 86/1941 Georgetown (GED) 86/1960 & 2024 Mount Pocono (MPO) 82/1941 Philadelphia (PHL) 88/1941 Reading (RDG) 86/1941 & 1994 Trenton (TTN) 87/1994 Wilmington (ILG) 86/1896

Record Warmest Low Temperatures April 15 Site Record/Year Allentown (ABE) 59/2002 AC Airport (ACY) 61/2002 AC Marina (55N) 59/2006 Georgetown (GED) 65/2002 Mount Pocono (MPO) 58/2002 Philadelphia (PHL) 64/2002 Reading (RDG) 64/1938 Trenton (TTN) 63/2002 Wilmington (ILG) 62/2002

Record High Temperatures April 16 Site Record/Year Allentown (ABE) 90/2012 AC Airport (ACY) 89/2002 AC Marina (55N) 88/2002 Georgetown (GED) 89/2002 Mount Pocono (MPO) 85/2002 Philadelphia (PHL) 90/2002 Reading (RDG) 90/2012 Trenton (TTN) 91/2012 Wilmington (ILG) 92/1896

Record Warmest Low Temperatures April 16 Site Record/Year Allentown (ABE) 60/1941 AC Airport (ACY) 62/2002 AC Marina (55N) 64/2002 Georgetown (GED) 65/2012 Mount Pocono (MPO) 56/2002 Philadelphia (PHL) 62/2002 Reading (RDG) 65/1941 Trenton (TTN) 62/2002 Wilmington (ILG) 63/2002

PHI WATCHES/WARNINGS/ADVISORIES

PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until 1 AM EDT Tuesday for ANZ450>455.