A cold front pushed into an unseasonably warm and humid airmass during the afternoon and evening hours of October 2, 2018. Many of the larger storm cells exhibited rotation.
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.
A cold front pushed into an unseasonably warm and humid airmass during the afternoon and evening hours of October 2, 2018. Many of the larger storm cells exhibited rotation. There were 16 confirmed across Pennsylvania, three of which occurred in central Pennsylvania. This turned out to be the largest October tornado outbreak, and the fourth largest outbreak overall, in Pennsylvania history.
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 Oct 2, 1:59 PM EST, 7 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 259 PM EDT Tue Oct 2 2018 .SYNOPSIS... Strong to severe thunderstorms with damaging winds and locally heavy rain may impact parts of central Pennsylvania this afternoon through early tonight as a fast moving but relatively weak cold front pushes through the region. Unseasonably warm and humid conditions will continue through midweek with another period of rain likely on Thursday. Cooler air is forecast trim the warmth into the weekend, but milder air and above normal temperatures will return by early next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Showers and several embedded thunderstorms will race east across the Northern Mtns of PA through late this afternoon. Increasing deep layer UVVEL and shear will work with significant breaks developing in the multi-layer cloud deck to help increase the threat for scattered severe TSRA during the to late afternoon hours across the NW mtns of PA before spreading farther south and east into a more unstable airmass between I-80 and I-76/PA Turnpike. Strong unidirectional westerly flow and relatively fast storm motions will support potential for locally damaging wind gusts. However, numerous runs of the HRRR (and EHI's off its sibling the RAP130, shows pockets of 0-1km EHI of over 2.5 m2/s2 within broader ares of 1.5-2.0 EHIs across primarily the Middle Susq Valley. Supercell composite index is greatest across the NW mtns with another area developing across parts of the Central Mtns and Middle Susq Valley. Two small areas (SE of the Lake Erie shore and near KSEG and KIPT) of Sig Tornado Parameter are found within these two broader supercell- favored areas. SPC's earlier expanded Day 1 SLGT risk area includes nearly all of the CWA. Despite progressive storm motions, the CAM guidance suggests training heavy downpours could produce localized rainfall amounts of 2+ inches across parts of north-central PA. WPC has a SLGT risk ERO that primarily covers the southern tier of NY/BGM CWA but does clip Tioga, Lycoming, Sullivan and Columbia counties. Nocturnal stabilization and limited forcing should result in deceasing coverage and intensity of showers/storms into early tonight. Models show the best chance for lingering rain/clouds after midnight over the Laurel Highlands aided by upslope. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... Rain-free conditions will return on Wednesday but without a noticeable drop in temperatures and humidity. High pressure will slide to the east by Thursday morning as the next frontal boundary approaches from the Great Lakes/Ohio Valley. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Models are in good agreement on the timing and the strength of a end of a long wave trough moving through the region Thursday. Multi- Layered clouds lurking to our south and west will increase quickly once again late Wednesday and Wednesday night with temps staying nearly steady or slowly rising and sfc dewpoints gradually rising again to unseasonably high levels in the 60s. Those min T's are 10 to 20 degrees above normal across the region. The trough extends from a large upper level low moving through Eastern Canada to a large high that is entrenched over the southeastern United States. Model guidance is in pretty good agreement in bringing another band of rain showers/isolated thunderstorms through the area from northwest to southeast Thursday into Thursday night. Friday looks dry though another wave is going to be moving through late Saturday into Sunday. However the position of the high looks further north which will starve the incoming system of moisture. So Saturday may turn out to be rather cloudy and cool. A strong upper ridge will dominate the pattern into next week with very high confidence in above average temperatures. Precipitation should be confined on the western periphery of the ridge within a sharp frontal zone extending from the Plains through the Great Lakes. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... A cold front approaching from the Grt Lks will bring a good chance of showers or thunderstorms during the late afternoon through early tonight, which could produce a brief episode of strong gusty winds and reduced visibility in spots. Across the northwest corner of the state, brief reductions from showers and thunderstorms will begin as early as this morning. Post-frontal low level moisture ascending the Allegheny Mountains is likely to result in low cigs tonight, beginning around 00Z at KBFD, then spreading south along the spine of the Alleghenies to KJST late at night. .Outlook... Wed...AM low cigs possible W Mtns. Thu...AM low cigs possible NW Mtns. Brief PM showers/vis reductions possible. Fri...Low cigs possible Laurel Highlands. Sat...Low cigs/drizzle possible. && .CTP WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until 2 AM EDT Wednesday for PAZ005-006-037- 041-042-046-051-053. && SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Lambert/Steinbugl LONG TERM...Ceru/Steinbugl AVIATION...Fitzgerald/Lambert
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</html>Special Weather Statement
National Weather Service State College PA
1107 AM EDT TUE OCT 2 2018
PAZ004-005-021545-
McKean PA-Warren PA-
1107 AM EDT TUE OCT 2 2018
...STRONG THUNDERSTORMS WILL AFFECT PARTS OF WARREN AND MCKEAN
COUNTIES UNTIL 1145 AM EDT...
At 1106 AM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Bradford to near Chapman State Park.
Movement was east at 40 mph.
Winds in excess of 40 mph are possible.
Locations impacted include...
Warren, Bradford, Port Allegany, Sheffield, Smethport, Shinglehouse,
Rew, Coryville, Crosby, Cyclone, Ludlow, Marshburg, Westline, Kinzua
Bridge State Park, Kinzua Dam, Chapman State Park, Warren South,
Mount Jewett, Eldred and Lewis Run.
LAT...LON 4185 7821 4170 7839 4171 7939 4200 7882
4200 7820
TIME...MOT...LOC 1506Z 269DEG 34KT 4198 7860 4174 7920
RXRSpecial Weather Statement
National Weather Service State College PA
159 PM EDT TUE OCT 2 2018
PAZ006-037-021900-
Potter PA-Tioga PA-
159 PM EDT TUE OCT 2 2018
...STRONG THUNDERSTORMS WILL AFFECT PARTS OF POTTER AND TIOGA
COUNTIES UNTIL 300 PM EDT...
At 158 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 8 miles north of Coudersport to 6 miles northeast
of Denton Hill State Park. Movement was east at 50 mph.
Pea size hail and winds in excess of 45 mph are possible.
Locations impacted include...
Mansfield, Elkland, Westfield, Genesee, Lawrenceville, Gaines,
Millerton, Keeneyville, Harrison Valley, Tioga, Knoxville, Ulysses,
Roseville, Oswayo, Osceola, Tioga Junction and Ski Denton Ski Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
Minor flooding may develop. Do not drive into water covering the
roadway.
These storms 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 4199 7692 4183 7690 4176 7764 4178 7794
4187 7821 4190 7821 4198 7793 4200 7776
4200 7696
TIME...MOT...LOC 1758Z 267DEG 47KT 4190 7804 4182 7772
LambertSpecial Weather Statement
National Weather Service State College PA
248 PM EDT TUE OCT 2 2018
PAZ037-021930-
Tioga PA-
248 PM EDT TUE OCT 2 2018
...A STRONG THUNDERSTORM WILL AFFECT PARTS OF TIOGA COUNTY UNTIL 330
PM EDT...
At 248 PM EDT, Doppler radar indicated a strong thunderstorm over
Wellsboro, moving east at 35 mph.
Dime size hail and wind gusts up to 50 mph are possible.
This strong thunderstorm will be near...
Mansfield, Covington and Blossburg around 310 PM EDT.
Other locations impacted by this storm include Mansfield University.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in State College PA.
&&
LAT...LON 4169 7689 4169 7735 4173 7743 4179 7741
4185 7690
TIME...MOT...LOC 1848Z 268DEG 29KT 4175 7731
LambertThe Binghamton radar (KBGM), 101 km away, was scanning. The volume nearest the first event began at 19:06 UTC.
16 thunderstorm wind, 6 hail, 3 funnel cloud. Local standard time, as filed.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees near Mansfield.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees along Route 958 in Freehold Township.
A funnel cloud was reported by the Scandia Volunteer Fire Department.
A funnel cloud was reported near Muncy.
A severe thunderstorm produced dime-sized hail southeast of Leonard Harrison State Park.
A severe thunderstorm produced golf ball-sized hail near Liberty.
Severel reports of funnel cloud sightings were received from around Liberty.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree across Powers Avenue in Johnsonburg.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees along Sher De Lin Road near I-80 east of DuBois.
A severe thunderstorm produced dime-sized hail near Rockton Mountain.
A severe thunderstorm produced dime-sized hail near DuBois.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires east of Beech Creek.
A severe thunderstorm produced ping pong ball-sized near Mill Hall.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires in Clintondale.
A severe thunderstorm produced hen egg-sized hail near Lamar.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires near Tylersville.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires near Runville.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees across a road near Blanchard.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires near Dalevue.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires near Linden Hall.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires near Linden Hall.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires near Spring Mills.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires near Benfer.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires near Beaver Springs.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees in Northumberland County along a line from Sunbury to Shamokin to Mount Carmel.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2018Every state in 2018This day in weather historyWarnings in Pennsylvania, October 2018
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 2026-10-01. Each event’s entry at NCEI: 779316, 779317, 779358, 779359, 779355, 779323, 779360, 779318, 779319, 779356, 779357, 779326, 779320, 779330, 779322, 779331, 779333, 779339, 779334, 779336, 779337, 779341, 779345, 779346, 779328.