Lower Macungie, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

034
FXUS61 KPHI 160525
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
125 AM EDT Sat May 16 2026

.WHAT HAS CHANGED...
Updated aviation discussion. No significant changes.

&&

.KEY MESSAGES...
1. A significant warming trend will take place beginning this
weekend and continuing into next week. High temperatures will
climb into the mid 80s to near 90 by Sunday with low 90s
expected for many areas Monday through Wednesday.

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...A significant warming trend will take place
beginning this weekend and continuing into next week. High
temperatures will climb into the mid 80s to near 90 by Sunday
with low 90s expected for many areas Monday through Wednesday.

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 into Monday for inland areas
with mid to upper 80s for many areas, and low 90s over portions
of eastern PA, inland southern NJ, and Delmarva. However the
flow be more out of the south to even southeast so they`ll be
more of cooling influence near the coast and even extending a
bit farther inland compared to Sunday. This will keep these
areas near the coast mainly in the 70s to low 80s. 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 4 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 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 looks to linger nearby
or just south of the area late next week and this could keep
some showers around at least into Thursday but perhaps even
Friday.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 12Z...VFR, becoming SKC. Winds mostly calm, if not
favoring a southwest direction less than 5 kts. High confidence.

Saturday...VFR/SKC. Southwest winds increasing to around 10-12
kts, gusting near 20 kts by 16Z. High confidence.

Saturday night...VFR conditions. Mid level clouds will push into
the region early in the night, with a low chance of a brief shower
or sprinkle at all terminals through 06Z. No restrictions
expected. High confidence.

Outlook...

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

Wednesday...Potential for sub VFR conditions with
afternoon/evening showers and storms likely.

&&

.MARINE...
Winds and seas are expected to remain below Craft Advisory
levels through tonight. For Saturday, southerly winds increase
with gusts up to 25 knots expected by late day into the evening.
Seas will also be increasing to around 5 feet. A Small Craft
Advisory is in effect for our coastal ocean zones that runs from
4 PM Saturday to 10 AM Sunday.

Outlook...

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

Tuesday through Wednesday...Southwest winds increase and could
reach Small Craft Advisory levels by late Tuesday into
Wednesday.

Rip Currents...

There is a MODERATE risk for the development of dangerous and
life threatening rip currents for the Jersey Shore and Delware
Beaches both Saturday and Sunday.

On Saturday, south winds will increase to 15 to 20 mph with 25
to 30 mph along with breaking waves of 2 to 3 feet with a 3 to 4
feet/9 to 10 period swell. There is still the potential for the
rip current risk to be upgraded to HIGH.

On Sunday, winds shift to more of a west to southwest flow at
10 to 15 mph. There will continue to be breaking waves of 2 to 3
feet with a 3 to 4 feet/9 to 10 period swell.

Important to note that while surface temperatures inland will
be in the low 80s on Saturday and in the upper 80s on Sunday,
temperatures along the coasts will mainly be in the 70s due to
ocean temperatures in the 50s. These cold water temperatures can
quickly cause hypothermia and physical incapacitation to anyone
suddenly immersed in the water.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 10 AM EDT
     Sunday for ANZ450>455.

&&

$$

DISCUSSION...Fitzsimmons/Staarmann
AVIATION...Fitzsimmons/Robertson/Staarmann
MARINE...Fitzsimmons/MPS/Staarmann