An environment ripe with instability and moisture coincided with the eastern edge of an elevated mixed layer (EML) allowed for scattered thunderstorm development during the afternoon and evening hours of May 18, 2026. Due to the lack of extremely favorable shear and lift, these thunderstorms struggled to develop further; however, inverted V soundings did allow for some damaging winds to mix down…
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CTP wrote it up.
An environment ripe with instability and moisture coincided with the eastern edge of an elevated mixed layer (EML) allowed for scattered thunderstorm development during the afternoon and evening hours of May 18, 2026. Due to the lack of extremely favorable shear and lift, these thunderstorms struggled to develop further; however, inverted V soundings did allow for some damaging winds to mix down to the surface across Centre County and Clinton County causing isolated wind damage.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS State College, PA wrote its last area forecast discussion before the first event at May 18, 5:35 PM EST, 1 hour 49 minutes earlier. Its key messages:
Area Forecast Discussion
National Weather Service State College PA
635 PM EDT Mon May 18 2026
.WHAT HAS CHANGED...
* Day 2 SPC Outlook upgraded to a Slight Risk (Level 2 out of
5) for damaging winds in northwest PA.
&&
.KEY MESSAGES...
1) Hottest temperatures of the year so far forecast this
afternoon along with some scattered storms in south central PA.
2) More heat & humidity will produce scattered showers and
thunderstorms on Tuesday afternoon and evening, some of which
could be strong to severe, especially across northern PA.
2) A strong cold front to bring showers and thunderstorms with
the potential for severe weather on Wednesday followed by
colder temperatures.
&&
.DISCUSSION...
KEY MESSAGE 1: Hottest temperatures of the year so far forecast this
afternoon along with some scattered storms in south central PA.
An expansive deck of fair weather cumulus had developed across
the Commonwealth this afternoon with very warm temperature and
sticky-but-not-overly-humid dewpoints. Convection has begun to
fire in the West Virginia panhandle and will continue to extend
north-northeastward this afternoon and evening as temperatures
continue to rise under an anomalous upper level ridge. 500 mb
heights per the GEFS will rise to near 590mb this afternoon
across southeast PA, correlating to standardized anomalies of +2
sigma along the Mid Atlantic Coast through 18z Tuesday.
We collaborated with LWX and SPC to paint a MRGL risk for SVR
TSRA this afternoon from the Scent Mtns to the West Branch
Valley of the Susq. This corridor will be near the eastern edge
of somewhat stronger (35-40 kt) swrly mid level winds with MU
CAPE reaching near 2000 J/KG. Additionally, the eastern edge of
an elevated mixed layer (currently over the Middle Ohio River
Valley) will be tracking ENE at 15-20 kts and reach the western
edge of the MRGL Risk area around 22-23Z today helping to
enhance mid level lapse rates and updraft intensity. The primary
hazard with these pulse storms will be the potential for gusty
winds associated with the the clearly high- based convection
occurring within an inverted-V sounding.
Daily record highs could be challenged in some locations. See
the Climate section for more details. Manual adjustments were
made to lower NBM maxT by a few degrees today due to a known
systematic bias correction issue identified during the shoulder
seasons. This should also keep max heat indices under 100F,
precluding any need for Heat Advisories. Still, heat risk
impacts will continue to be monitored given the quick ramp-up in
heat and limited acclimation time.
Dewpoints over 60F for many will also feel more humid relative
the recent cool stretch we've had.
-------------------------------------------------------------
KEY MESSAGE 2: More heat & humidity will produce scattered
showers and thunderstorms on Tuesday afternoon and evening, some
of which could be strong to severe, especially across northern
PA.
By Tuesday, we'll still be under the influence of the
anomalously strong ridge of high pressure, with broad
southwesterly flow continuing to pump warmer temperatures and
humid conditions into Pennsylvania. Highs on Tuesday should be
fairly comparable to today, though afternoon showers/storms in
the west could limit how warm it gets there.
At the surface, a deepening surface low will lift across the
Great Lakes with gradually sinking heights aloft impinging
northwest PA. Underneath this sprawling ridge, Pennsylvania
will be in a moist and unstable airmass with MUCAPE values
expected to reach 1000-1500J/kg. With marginal but sufficient
shear, this amount of instability could support a few stronger
storms will strong to damaging wind gusts. The SPC upgraded NW
PA to a Slight Risk (Level 2 out of 5) of severe weather Tuesday
afternoon. The Marginal Risk extends down to about halfway
between I-80 and I-76. Low level hodographs do exhibit some
spin and an isolated tornado cannot be ruled out in northwest PA
closer to the parent surface low pressure system. CAMs disagree
on the extent to which convection initiation will occur Tuesday
afternoon, but the heat and humidity will provide as much fuel
for storm development as we've seen yet this year.
Rainfall amounts are not expected to be all that impressive with
this system, largely owing to unimpressive/relatively dry
moisture profiles with dewpoints in the upper 50s to low 60s.
The good news is that these lower dewpoints will keep our heat
index values below 100F and mitigate the need for Heat
Advisories across the area. Rainfall amounts will be highest
west of I-99 and locations farther east may not see much rain at
all before Wednesday.
--------------------------------------------------------------
KEY MESSAGE 3: A strong cold front to bring showers and
thunderstorms with the potential for severe weather on Wednesday
followed by colder temperatures.
A cold front (accompanied by more widespread and frequent
showers/t-storms) brings relief to the relatively short bout of
heat and moderate humidity Wednesday into Thursday. High
temperatures on Wednesday in northwest PA (behind the front)
will be nearly 20 degrees cooler than Monday/Tuesday. The Lower
Susquehanna Valley will squeak out another warm day with highs
in the upper to 80s to near 90F.
Ahead of and along the front, there will be a risk for severe
weather again on Wednesday. The magnitude & location of the
severe threat will be highly dependent on cold front passage
timing and amount of cloud cover in advance of the frontal
boundary. A Marginal Risk area covers locations south and east
of the I-80/I-99 corridor and highlights locations along and
downstream of the cold front between 12PM and 8PM on Wednesday.
A few of the hi-res models depict a slower cold front passage.
Such a solution would allow for more destabilization ahead of
the front and a higher threat for damaging straight line winds.
If the front ends up being faster than progged, clouds/rain in
the morning could limit instability and lead to an unimpressive
gusty shower event. Regardless, this system will feature
beneficial rainfall with rainfall amounts generally 0.10-0.25"
and locally higher totals possible in thunderstorms.
In the wake of the cold front, high pressure will build in for
a short time. Temperatures are forecast to cool down back to
historical/climo averages for late May for the end of next week.
Early indications show the aforementioned cold front stalling
out south of the Mason-Dixon line late in the week and lifting
back north across PA as a warm front into Memorial Day weekend.
The current outlook favors a cooler/wetter stretch through the
holiday weekend thanks to that warm front, but there is still
a lot of time for the forecast to trend in a more favorable and
optimistic direction for the holiday weekend that marks the
unofficial start of summer.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
Scattered cumulus clouds have been noted moving over the central
Pennsylvania air space. Flight conditions are expected to remain
VFR throughout the TAF period outside of a an isolated
thundershower this afternoon. Confidence is overall low on
thunderstorm development this afternoon. Forcing for storms is
weak despite the available energy in the atmosphere. Latest CAM
guidance would indicate a narrow window for convective storms to
develop after 22Z this afternoon. These storms will be very
isolated in nature, and PROB30 groups have been included at
airfields that may see one of these storms.
Overnight, a shortwave tracking across the Great Lakes may
result in a few showers/thundershowers across West-Central PA
(mainly KBFD), though flight restrictions appear unlikely with
this activity. After 12Z on Tuesday clouds will begin to scatter
out again and clear, with wind gusts up to 25kts possible again
on Tuesday throughout the afternoon.
Outlook...
Tue...Mainly VFR. Patchy A.M. fog possible. Isolated P.M.
shower or t-storm possible.
Wed...Restrictions probable through Wednesday night with
widespread showers/storms along CFROPA.
Thu...Lingering showers across S PA, restrictions possible.
Fri...Lingering showers across S PA, restrictions possible.
&&
.CLIMATE...
The following climate sites across central Pennsylvania set new
daily high temperature records for May 18th:
* A record high temperature of 92 degrees was set in Altoona,
breaking the previous record of 91 degrees initially set back
in 1962. This record was tied two times previously, back in
1996 and 2017.
* A record high temperature of 86 degrees was set in Bradford,
breaking the previous record of 85 degrees set back in 1962.
** Note: The high temperature for State College will be reported
around 7AM on 5/19. This is due to the State College CO-OP
observations running 7AM-7AM. Thus, today's (5/18) high
temperature will be reported in tomorrow's (5/19) observation.
This record, for reference, is 92 degrees set in 1962.
---------------------------------------------
Abnormally warm temperatures will continue on May 19th, thus
multiple sites could challenge daily record high temperatures.
Daily Maximum High Temperatures for May 19th:
* Harrisburg: 95F set in 1962
* Williamsport: 96F in in 1996
* Altoona: 92F set in 1996
* Bradford: 85F set in 1962
* State College: 92F set in 1934, tied in 1996.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Air Quality Alert until midnight EDT tonight for PAZ057-059-
063-065-066.
&&
WHAT HAS CHANGED...Banghoff
KEY MESSAGES...Lambert/Banghoff
DISCUSSION...Lambert/Banghoff
AVIATION...Bowen/Teare
CLIMATE...BeatyHazardous Weather Outlook National Weather Service State College PA 239 AM EDT Mon May 18 2026 PAZ004>006-010>012-017-018-037-041-042-190645- Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield- Northern Centre-Tioga-Northern Lycoming-Sullivan- 239 AM EDT Mon May 18 2026 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Isolated to scattered strong to severe thunderstorms with gusty winds and a few instances of hail are possible Tuesday afternoon and evening. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ024-025-033-190645- Cambria-Blair-Somerset- 239 AM EDT Mon May 18 2026 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Monday through Saturday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ019-045-046-049>053-190645- Southern Centre-Southern Clinton-Southern Lycoming-Union-Snyder- Montour-Northumberland-Columbia- 239 AM EDT Mon May 18 2026 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. Isolated to scattered strong to severe thunderstorms with gusty winds are possible late this afternoon and evening. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Isolated to scattered strong to severe thunderstorms with gusty winds and a few instances of hail are possible expected Tuesday afternoon and evening. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ026>028-034>036-056>059-063>066-190645- Huntingdon-Mifflin-Juniata-Bedford-Fulton-Franklin-Perry-Dauphin- Schuylkill-Lebanon-Cumberland-Adams-York-Lancaster- 239 AM EDT Mon May 18 2026 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. Isolated to scattered strong to severe thunderstorms with gusty winds are possible late this afternoon and evening. .DAYS TWO THROUGH SEVEN...Monday through Saturday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. Lambert
Special Weather Statement
National Weather Service State College PA
544 PM EDT Mon May 18 2026
PAZ035-036-182215-
Fulton PA-Franklin PA-
544 PM EDT Mon May 18 2026
...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL FRANKLIN AND
EASTERN FULTON COUNTIES THROUGH 615 PM EDT...
At 544 PM EDT, Doppler radar was tracking a strong thunderstorm near
Breezewood, moving northeast at 30 mph.
HAZARD...Wind gusts of 50 to 55 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
McConnellsburg, Harrisonville, Big Cove Tannery, and Fort Littleton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 3991 7820 4011 7797 4010 7792 4009 7790
4006 7787 4003 7781 3982 7808
TIME...MOT...LOC 2144Z 221DEG 28KT 3993 7808
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH
BeatySpecial Weather Statement
National Weather Service State College PA
736 PM EDT Mon May 18 2026
PAZ018-019-025-190000-
Northern Centre PA-Blair PA-Southern Centre PA-
736 PM EDT Mon May 18 2026
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN CENTRE AND
NORTHEASTERN BLAIR COUNTIES THROUGH 800 PM EDT...
At 736 PM EDT, Doppler radar was tracking a strong thunderstorm near
Tyrone, moving northeast at 35 mph.
HAZARD...Wind gusts of 50 to 55 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Stormstown, Bald Eagle, Milesburg, Snow Shoe, Clarence, Port Matilda,
Sandy Ridge, Julian, Black Moshannon State Park, and Unionville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4095 7775 4073 7809 4074 7811 4070 7820
4076 7830 4107 7796
TIME...MOT...LOC 2336Z 230DEG 32KT 4081 7814
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH
BeatySpecial Weather Statement
National Weather Service State College PA
750 PM EDT Mon May 18 2026
PAZ019-190015-
Southern Centre PA-
750 PM EDT Mon May 18 2026
...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN CENTRE COUNTY
THROUGH 815 PM EDT...
At 750 PM EDT, Doppler radar was tracking a strong thunderstorm over
State College, moving northeast at 35 mph.
HAZARD...Wind gusts of 50 to 55 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Boalsburg, Pleasant Gap, Centre Hall, Millheim, Aaronsburg, Spring
Mills, Madisonburg, Potters Mills, Tussey Mountain Ski Area, and
Pennsylvania Military Museum.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4074 7782 4074 7784 4075 7786 4100 7758
4090 7742 4072 7777
TIME...MOT...LOC 2350Z 224DEG 32KT 4077 7777
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH
BeatySpecial Weather Statement
National Weather Service State College PA
800 PM EDT Mon May 18 2026
PAZ012-018-019-190030-
Northern Centre PA-Northern Clinton PA-Southern Centre PA-
800 PM EDT Mon May 18 2026
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL CENTRE AND CENTRAL
CLINTON COUNTIES THROUGH 830 PM EDT...
At 759 PM EDT, Doppler radar was tracking a strong thunderstorm near
Black Moshannon State Park, moving northeast at 40 mph.
HAZARD...Wind gusts of 50 to 55 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Snow Shoe, Monument, Black Moshannon State Park, and Orviston.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4085 7799 4090 7808 4123 7774 4113 7758
TIME...MOT...LOC 2359Z 219DEG 35KT 4095 7797
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH
BeatySpecial Weather Statement
National Weather Service State College PA
803 PM EDT Mon May 18 2026
PAZ019-026-190030-
Huntingdon PA-Southern Centre PA-
803 PM EDT Mon May 18 2026
...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL HUNTINGDON AND
SOUTH CENTRAL CENTRE COUNTIES THROUGH 830 PM EDT...
At 803 PM EDT, Doppler radar was tracking a strong thunderstorm near
Warriors Mark, moving northeast at 25 mph.
HAZARD...Wind gusts of 50 to 55 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
State College, Park Forest Village, Stormstown, Lemont, Houserville,
Warriors Mark, Pine Grove Mills, Ramblewood, Port Matilda, Julian,
Rock Springs, Unionville, Pennsylvania State University, and State
College Regional Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4070 7810 4072 7815 4073 7813 4074 7812
4075 7813 4096 7785 4085 7774 4069 7793
TIME...MOT...LOC 0003Z 237DEG 21KT 4073 7807
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH
BeatySpecial Weather Statement
National Weather Service State College PA
816 PM EDT Mon May 18 2026
PAZ019-045-190045-
Southern Clinton PA-Southern Centre PA-
816 PM EDT Mon May 18 2026
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL CENTRE AND SOUTH CENTRAL
CLINTON COUNTIES THROUGH 845 PM EDT...
At 816 PM EDT, Doppler radar was tracking a strong thunderstorm over
Bellefonte, moving northeast at 40 mph.
HAZARD...Wind gusts up to 50 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Bellefonte, Boalsburg, Pleasant Gap, Lamar, Lemont, Zion,
Houserville, Centre Hall, Milesburg, Blanchard, Rebersburg,
Madisonburg, Bald Eagle State Park, Howard, Beech Creek, State
College Regional Airport, and Pennsylvania Military Museum.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 4097 7739 4078 7779 4080 7784 4088 7786
4107 7767 4111 7758 4111 7756
TIME...MOT...LOC 0016Z 235DEG 35KT 4091 7774
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH
ColbertThe State College radar (KCCX), 16 km away, was scanning. The volume nearest the first event began at 00:21 UTC.
2 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm, producing wind gusts estimated near 60 mph knocked down a tree that fell onto a garage and car. This tree falling also damaged the roof of a residence with no injuries reported in Park Forest.
A severe thunderstorm, producing wind gusts estimated near 60 mph, knocked down a tree onto wires in the 500 block of High Street in Flemington.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2026Every state in 2026This day in weather historyWarnings in Pennsylvania, May 2026
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1337735, 1337737.