Severe Thunderstorm Warning 287, NWS Philadelphia/Mount Holly

183 
WWUS51 KPHI 081715
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
115 PM EDT Sat Aug 8 2026

PAC029-081745-
/O.CON.KPHI.SV.W.0287.000000T0000Z-260808T1745Z/
Chester PA-
115 PM EDT Sat Aug 8 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM EDT
FOR WESTERN CHESTER COUNTY...

At 115 PM EDT, severe thunderstorms were located along a line
extending from Gap to near Homeville to Octoraro, moving east at 30
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Coatesville, Oxford, Parkesburg, West Grove, Honey Brook, Glen Roy,
Homeville, Cochranville, Glenmoore, Mount Vernon, Atglen, South
Coatesville, and Modena.

This includes Pennsylvania Turnpike between mile markers 305 and 307.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Mount Holly NJ.

&&

LAT...LON 4010 7594 4014 7572 3972 7586 3972 7613
      3973 7613 3974 7612 3973 7610 3974 7610
      3976 7606 3981 7603 3983 7604 3987 7599
      3995 7600 4004 7593
TIME...MOT...LOC 1715Z 266DEG 24KT 4001 7602 3985 7603 3966 7614 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MPS

679 
WWUS51 KPHI 081737
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
137 PM EDT Sat Aug 8 2026

PAC029-081745-
/O.EXP.KPHI.SV.W.0287.000000T0000Z-260808T1745Z/
Chester PA-
137 PM EDT Sat Aug 8 2026

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN CHESTER COUNTY WILL
EXPIRE AT 145 PM EDT...

The storms which originally prompted the warning are moving out of 
the warning area. Therefore, this warning will be allowed to expire. 
However, storms are redeveloping, and a new Severe Thunderstorm 
Warning is in effect for portions of Western Chester County until 
215 PM EDT.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
southeastern Pennsylvania.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 4010 7594 4014 7572 3972 7586 3972 7613
      3973 7613 3974 7612 3973 7610 3974 7610
      3976 7606 3981 7603 3983 7604 3987 7599
      3995 7600 4004 7593
TIME...MOT...LOC 1735Z 261DEG 25KT 4003 7586 3987 7587 3968 7598 

$$

MPS

Area Forecast Discussion
National Weather Service Mount Holly NJ
720 AM EDT Sat Aug 8 2026

.WHAT HAS CHANGED...
No significant changes to the forecast.

&&

.KEY MESSAGES...
1. Hot and humid conditions are expected to persist through
Tuesday of next week, though an improvement in humidity is
expected Sunday into Monday. A Heat Advisory is in effect for
portions of the area through today.

2. Isolated to scattered showers and thunderstorms are forecast
to develop this afternoon and evening. Sunday still looks to be
largely dry, then daily chances for showers and thunderstorms
will return Monday and into the middle of next week. There is
at least a marginal risk for localized heavy rainfall leading
to flash flooding and locally damaging wind gusts with any
stronger thunderstorms that develop.

&&

.DISCUSSION...
KEY MESSAGE 1...Hot and humid conditions are expected to
persist through Tuesday of next week, though an improvement in
humidity is expected Sunday into Monday. A Heat Advisory is in
effect for portions of the area through today.

A relatively stagnant synoptic pattern will remain in place
across our region. Quasi zonal mid and upper level flow will be
in place through the middle of next week as Bermuda high
pressure persists offshore. This will keep a steady stream of
very warm and moist air in place across the region through the
period.

A prolonged period of hot and humid conditions will continue
for the next several days. With dewpoints remaining in the low
to mid 70s and highs in the upper 80s to low 90s today, heat
indices will again be near 100 degrees this afternoon, mainly
along and southeast of the I-95 corridor. A weak cold frontal
passage Sunday will help usher in slightly drier air and allow
dewpoints to mix out during the afternoon hours both Sunday and
Monday. This will give some slight reprieve from the excessive
humidity, though highs will still be in the upper 80s to low or
even mid 90s. The lower dewpoints Sunday and Monday will result
in maximum heat indices mainly in the mid to upper 90s, though
could get near 100 degrees in Delmarva and far southern New
Jersey. Since the forecast is decidedly below Heat Advisory
criteria, we've opted not to extend it to cover additional days
at this time, though it will still be hot and humid.

A Heat Advisory remains in effect through 8 PM this evening for
portions of southeastern Pennsylvania, portions of New Jersey,
and northern Delware.

Moisture advection will return again by Tuesday ahead of
another cold front, and slightly more humid conditions should
return for Tuesday. A somewhat stronger cold front looks to come
through late Tuesday or Wednesday, which will help bring a
slight reduction in temperatures. Highs by Wednesday and
Thursday are mostly in the mid to upper 80s, which will be
closer to average for early to mid August.

KEY MESSAGE 2...Isolated to scattered showers and thunderstorms
are forecast to develop this afternoon and evening. Sunday
still looks to be largely dry, then daily chances for showers
and thunderstorms will return Monday and into the middle of next
week. There is at least a marginal risk for localized heavy
rainfall leading to flash flooding and locally damaging wind
gusts with any stronger thunderstorms that develop.

The evolution of today's convection remains a little unclear
still. A feature of interest will be the convective complex
currently across the upper Ohio Valley early this morning. While
that activity should weaken later this morning, it's remnants
will likely become a focus for forcing diurnally driven
convection in our region later today as it drifts eastward.
CAMs still suggesting isolated to scattered thunderstorms
developing across the area this afternoon and evening. Synoptic
forcing isn't as strong as what we had Friday, though the
remnant dynamics from the convection upstream could give us
better forcing at the mesoscale level. So we could see more
widespread thunderstorms than CAMs suggest, but not super
confident on that at the moment. PWATs look slightly lower than
today, but overall the thermodynamics appear similar to Friday
(2000-3000 J/kg CAPE). Notably, mean flow is more westerly and
a bit stronger than Friday, so deep layer wind shear is a little
stronger in the 25-30 kt range. This will pose more of a large
hail risk compared to Friday as well, but damaging winds will be
the main threat with any stronger storms. Locally heavy
rainfall leading to flash flooding is also possible, but
thinking the stronger flow aloft should keep storms moving
faster and pose slightly less of a flash flood risk.

We remain in a Marginal (level 1 out of 4) Risk for excessive
rainfall from WPC. SPC has maintained the Marginal (level 1 out
of 5) Risk for severe thunderstorms for most of our area.

We look to have a weak cold frontal passage by Sunday, ushering
in slightly drier air. This combined with subtle subsidence
aloft will help briefly limit convection potential on Sunday,
though cannot completely rule out some isolated sea breeze
convection in the afternoon.

Better support for forcing aloft will return by late Monday as
mean flow shifts more westerly and mid level flow increases.
At this point though, it appears the greater threat of storms
will be to our northwest on Monday where SPC has a Marginal Risk
highlighted. Still could get some isolated storms, but Monday is
trending drier locally as the lingering lower dewpoints should
limit our instability a bit. Better moisture and instability
return by Tuesday though, along with better storm chances. With
the stronger mid level flow aloft, severe thunderstorms still
look to be a greater threat compared to flash flooding, but
these details remain unclear.

A somewhat stronger cold front looks to come through late
Tuesday or Wednesday, which will help break the excessive heat
and humidity some, but the pattern aloft may still support
diurnally driven convection.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...Any restrictions in fog/stratus will clear by 13Z or
so, then VFR. Isolated to scattered thunderstorms in the
afternoon may cause localized restrictions, however confidence
on where any of this may develop is low. Opted to include PROB30
groups for TSRA at all terminals. Southwest winds increasing to
near 10 kts, with gusts near 18 kts by 18Z. High confidence in
prevailing VFR, low confidence on shower and storm details.

Tonight...Prevailing VFR, though some patchy fog may develop.
Some isolated showers and thunderstorms could linger through
06Z, but confidence on this is too low to include a TAF mention
at this time. Southwest winds near 5 kts or less. Moderate
confidence.

Outlook...

Sunday-Sunday night...VFR conditions expected.

Monday-Wednesday...Mostly VFR except restrictions possible with
afternoon/evening showers and thunderstorms.

&&

.MARINE...
No prevailing marine hazards are expected through tonight.
Southwest to south winds around 10-20 kt with seas of 2-4 feet.
A 20-40% chance of a thunderstorm this afternoon into tonight
with briefly higher winds and seas possible.

Outlook...

Sunday through Wednesday...No prevailing marine hazards
expected. Isolated storms could develop along the sea breeze
Sunday, potentially impacting the back bays or nearshore
waters. Thunderstorms possible Tuesday and Wednesday nights.

Rip Currents...

For today...Southwesterly winds continue and should increase
some to 10-20 mph. Breaking waves in the surf zone are forecast
to increase some, especially for much of the Jersey Shore, at 2
to 3 feet. Given the increasing surf and southerly winds, went
with a MODERATE risk for the development of dangerous rip
currents for most of the Jersey Shore. Breaking waves should be
a little lower and winds will have more of an offshore or shore
parallel component for the Delaware Beaches and coastal
Monmouth County, therefore went with a LOW risk for the
development of dangerous rip currents.

For Sunday...Similar conditions Sunday as today. Southwesterly
winds continue around 10-15 mph. Breaking waves in the surf
zone are forecast to remain 1 to 3 feet. Maintained the same
risk of rip currents for all coastal areas.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 8 PM EDT this evening for PAZ070-071-
     101>106.
NJ...Heat Advisory until 8 PM EDT this evening for NJZ008>010-
     012>015-017>020-027.
DE...Heat Advisory until 8 PM EDT this evening for DEZ001.
MD...None.
MARINE...None.

&&

DISCUSSION...Guzzo/Staarmann
AVIATION...Staarmann
MARINE...Gorse/Staarmann

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
534 AM EDT Sat Aug 8 2026

MDZ012-015-019-020-090915-
Kent MD-Queen Annes-Talbot-Caroline-
534 AM EDT Sat Aug 8 2026

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

There is a risk of isolated severe thunderstorms this afternoon and
evening, with potential for damaging winds and locally heavy rainfall
leading to flash flooding being the main threats.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Hot and humid conditions will persist through Tuesday along with
daily chances for showers and thunderstorms. Chances for severe
thunderstorms will return on Tuesday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

Staarmann