A line of severe thunderstorms developed ahead of an approaching cold front during the afternoon of May 15, 2018. This line progresses southeastward across central Pennsylvania, producing widespread wind damage and isolated large hail.
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 line of severe thunderstorms developed ahead of an approaching cold front during the afternoon of May 15, 2018. This line progresses southeastward across central Pennsylvania, producing widespread wind damage and isolated large hail.
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 15, 6:09 AM EST, 5 hours 18 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 709 AM EDT Tue May 15 2018 .SYNOPSIS... Severe thunderstorms capable of significant damaging wind are forecast Tuesday afternoon and evening across parts of central Pennsylvania. A wet and muggy weather pattern will persist through late week into the weekend with areas of locally heavy rain and risk of flash flooding. && .NEAR TERM /THROUGH TONIGHT/... Elevated convection crossing Lake Erie early this morning and brushing the NW zones with brief heavy downpours and perhaps some pea sized hail. Spotty shower/T-storm could still develop over the eastern 1/2 of the area as WAA zone continues to lift northeast. Locally dense fog has improved and should dissipate by 9AM. In the wake of isolated early morning showers/convection and associated mid level cloud debris, diabatic heating and advection of low to mid 60s dewpoints is expected to contribute to moderate instability. Vort max currently over IL along with southeastward advancing cold front are likely catalysts for organized storm initiation moving into a very favorable thermodynamic and kinematic environment. The individual CAMs along with the HREF mean and experimental HRRR- TLE and HRRRE are very bullish on an intense T-storm complex with significant damaging wind threat -- particularly moving across north-central into northeast PA this afternoon/evening. The convective complex should evolve into line segments/bows with high probability of 50+kt damaging winds. SPC increased the ENH risk area a bit while adding a sig severe hatched area to indicate 10% or greater probability of wind gusts 65kt or greater within 25 miles of point. The tail end of the convection appears to hang up across far south-central PA this evening, with potential for repeat storms along merging boundaries. High moisture availability/PW should spur heavy downpours with a risk of localized flash flooding. While we would have preferred to use the flash flood watch in a more short-fused fashion, collaborated with PBZ/LWX/PHI to pull trigger on FF watch this cycle. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... A wet and humid weather pattern is expected to last through the end of the week as tropical moisture flowing northward collides with a stalled frontal zone across the Mid Atlantic region. This should result in some relatively cooler days (vs. mid-May climo) and warmer nights given moist/humid airmass. Highest precip probs are over south-central PA. && .LONG TERM /SATURDAY THROUGH MONDAY/... A persistent flow of subtropical moisture interacting with a quasi-stationary frontal system will keep conditions soggy over the region for the foreseeable future. The front will wag north and south for the next several days bringing periods of showers and thunderstorms with very little chance of any 12 hour period remaining dry in any one location. Proximity of drier air mass and high pressure to the north over southern Canada means that drier air will filter southward into far northern PA from time to time, giving at least some chance of periodic drier periods this week, but the main story is for daily chances of showers and thunderstorms until further notice. The Thursday night into Friday timeframe looks particularly wet as deep layer moisture surges (PW near 2.0") thanks to amplification of the offshore upper ridge coupled with a nearly stationary upper trough over the central plains. This will direct copious subtropical moisture northward into the eastern GLAKS and set the stage for locally heavy rains and potential flooding given what will have been a very wet week by that time. Temperatures should be above seasonal climate averages this week with a muggy summertime/humid feel given dewpoints in the 60s. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... 07Z regional radar loop showing a few isolated showers/thunderstorms popping up along approaching warm front, running from northeast Ohio to northern Virginia. As the front moves northeast, there could be a a few showers or thunderstorms across central Pa overnight, mainly over the northwest part of the state. Any shower or storm could be accompanied by a brief vis reduction. Model soundings and SREF prob charts also indicate the possibility (<50pct) for a brief period of IFR cigs in the vicinity of KBFD early Tuesday morning associated with passage of the front. Perhaps the biggest concern overnight will be the possibility of fog across eastern Pa. Dewpoint depressions already low in this area, and when skies clear expect fog to develop between 05Z-08Z. Latest SREF prob charts and NAMNest indicate the Susquehanna Valley (especially KIPT/KLNS) is the area most likely to experience significant vis reductions early Tuesday morning. Any fog should mix out by 13Z-14Z over eastern Pa, followed by widespread VFR conditions for late morning. A cold front will push south across the region Tuesday afternoon, accompanied in many locations by a round of strong to potentially severe thunderstorms, with briefly reduced cigs/vsbys and possible strong wind gusts. Outlook... Wed-Thu...Rain/low cigs possible, mainly southern Pa. Fri...Rain/low cigs likely. Sat...Rain/low cigs possible. && .HYDROLOGY... Some repeat/training convection (on the tail end of fcst damaging Tstm wind complex) is possible across the southern tier of central PA mainly this evening. Collaborated with adjacent offices on FF watch across srn PA although would have preferred to issue a more short-fused watch. 1-3hr FFGs as low as 1-1.5 inches suggest some runoff problems are possible. Deep moisture feed advecting northward along stalled frontal boundary suggests potential for heavy rain/FF risk through late week. Current WPC EROs favor areas just south of PA for marginal to slight risk of flash flooding. && .CTP WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch from 2 PM EDT this afternoon through this evening for PAZ033>036-056-057-059-063>066. && SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Steinbugl LONG TERM...DeVoir AVIATION...Gartner HYDROLOGY...Steinbugl
Hazardous Weather Outlook National Weather Service State College PA 451 AM EDT Tue May 15 2018 PAZ033>036-056-057-059-063>066-160900- Somerset-Bedford-Fulton-Franklin-Perry-Dauphin-Lebanon-Cumberland- Adams-York-Lancaster- 451 AM EDT Tue May 15 2018 ...FLASH FLOOD WATCH IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH THIS EVENING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and Tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Flash Flood Watch. Scattered severe thunderstorms with damaging winds 60 mph or greater and large hail exceeding 1 inch in diameter are possible Tuesday afternoon and evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ005-006-010>012-017>019-024>028-045-049-050-160900- McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield- Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin- Juniata-Southern Clinton-Union-Snyder- 451 AM EDT Tue May 15 2018 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and Tonight. Scattered severe thunderstorms with damaging winds 60 mph or greater and large hail exceeding 1 inch in diameter are possible Tuesday afternoon and evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ037-041-042-046-051>053-058-160900- Tioga-Northern Lycoming-Sullivan-Southern Lycoming-Montour- Northumberland-Columbia-Schuylkill- 451 AM EDT Tue May 15 2018 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and Tonight. Numerous severe thunderstorms with significant damaging winds 60 to 70 mph or greater and large hail exceeding 1 inch in diameter are probable Tuesday afternoon and evening. A few tornadoes are also possible. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ004-160900- Warren- 451 AM EDT Tue May 15 2018 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and Tonight. Strong to severe thunderstorms with gusty winds and small hail are possible early Tuesday afternoon. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. MS
Special Weather Statement
National Weather Service State College PA
816 AM EDT TUE MAY 15 2018
PAZ037-151300-
Tioga PA-
816 AM EDT TUE MAY 15 2018
...STRONG THUNDERSTORMS WILL AFFECT PARTS OF TIOGA COUNTY UNTIL 900
AM EDT...
At 815 AM EDT, Doppler radar indicated several strong thunderstorms
along a line extending from near Westfield to 6 miles west of
Keeneyville to near Gaines. Movement was east at 55 mph.
Dime size hail and wind gusts up to 50 mph are possible.
Locations impacted include...
Mansfield, Wellsboro, Elkland, Keeneyville, Millerton, Leonard
Harrison State Park, Covington, Westfield, Lawrenceville, Gaines,
Blossburg, Tioga, Roseville, Knoxville, Osceola, Tioga Junction and
Mansfield University.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 4169 7689 4168 7756 4185 7753 4200 7759
4200 7693
TIME...MOT...LOC 1215Z 263DEG 50KT 4196 7749 4185 7742 4174 7748
LambertPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1057 AM EDT TUE MAY 15 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0224 PM TSTM WND DMG 1 E SEVEN SPRINGS 40.03N 79.27W
05/14/2018 SOMERSET PA FIRE DEPT/RESCUE
TREE DOWN JUST EAST OF SEVEN SPRINGS.
&&
EVENT NUMBER CTP1801800
MRCSpecial Weather Statement
National Weather Service State College PA
1138 AM EDT TUE MAY 15 2018
PAZ004-005-010-151630-
McKean PA-Warren PA-Elk PA-
1138 AM EDT TUE MAY 15 2018
...STRONG THUNDERSTORMS WILL AFFECT PARTS OF ELK...WARREN...AND
MCKEAN COUNTIES UNTIL 1230 PM EDT...
At 1137 AM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Enterprise to 7 miles southeast of Oil City
to 9 miles east of Grove City. Movement was east at 75 mph.
Pea size hail and wind gusts up to 50 mph are possible.
Strong thunderstorms will be near...
Sheffield and Chapman State Park around 1200 PM EDT.
Ludlow around 1205 PM EDT.
James City and Wetmore around 1210 PM EDT.
Kane, Marshburg and Westline around 1215 PM EDT.
East Branch Dam around 1220 PM EDT.
Rew, Portland Mills and Cyclone around 1225 PM EDT.
Other locations impacted by these storms include Tidioute, Eldred,
Mount Jewett, Lewis Run and Clarendon.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
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 4167 7961 4200 7820 4169 7821 4162 7828
4161 7842 4146 7842 4141 7846 4132 7887
4137 7897 4134 7910 4141 7910 4145 7906
4144 7896 4162 7896 4163 7961
TIME...MOT...LOC 1537Z 250DEG 64KT 4160 7963 4137 7960 4115 7990
Lambert/ScullyThe State College radar (KCCX), 83 km away, was scanning. The volume nearest the first event began at 16:25 UTC.
52 thunderstorm wind, 6 hail. Local standard time, as filed.
A severe thunderstorm producing winds estimated near 60 mph knocked down wires onto a roadway north of Ridgway.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires along Chicken Hill Road.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree and wires in Saint Marys.
A severe thunderstorm producing winds estimated near 90 mph knocked down numerous trees and wires along Huston Hill Road.
A severe thunderstorm producing winds estimated near 95 mph knocked down numerous trees and wires along Route 120.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires along Route 120 near Wyside.
A severe thunderstorm producing winds estimated near 60 mph knocked down a large tree, blocking Main Street at Spruce Street in Mahaffey.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree onto wires and blocked a roadway west of Westover.
A severe thunderstorm producing winds estimated near 60 mph knocked down multiple trees near Osceola Mills.
A severe thunderstorm producing winds estimated near 60 mph knocked down numerous trees onto wires.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires along Black Moshannon Road.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires onto a home.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto Sellers Lane.
A severe thunderstorm produced quarter-sized hail near Portage.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires along Seibert Road near Bellefonte.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto Melanie Lane in Pleasant Gap.
A severe thunderstorm produced a wind gust of 58 mph at the KUNV ASOS at University Park Airport.
A severe thunderstorm produced half dollar sized south of Lilly.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires onto Route 87 near Forksville.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees in Dushore.
A severe thunderstorm producing winds estimated near 60 mph knocked down multiple trees, including one onto a house east of Muncy.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree onto a home in Hughsville.
A severe thunderstorm producing winds estimated near 60 mph blew a roof off of a building in Mifflinburg.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees in Turbotville.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees north of Newton-Hamilton.
A severe thunderstorm producing winds estimated near 80 mph knocked down numerous trees in Danville.
A severe thunderstorm producing winds estimated near 90 mph knocked down numerous trees near Riverside.
A severe thunderstorm producing winds estimated near 90 mph knocked down a large tree onto Sunbury Road near Avenue E.
A severe thunderstorm producing winds estimated near 80 mph overturned a tractor trailer on the bridge between Danville and Riverside.
A severe thunderstorm producing winds estimated near 60 mph knocked down numerous trees down in Bloomsburg.
A severe thunderstorm producing winds estimated near 85 mph knocked down numerous trees near Pealertown.
A severe thunderstorm producing winds estimated near 90 mph knocked down and snapped numerous trees along Clinic Road.
A severe thunderstorm producing winds estimated near 85 mph knocked down numerous trees along Chapins Road near Sycamore Lane.
A severe thunderstorm producing winds estimated near 60 mph blew a roof off of a home in Berwick.
A severe thunderstorm producing winds estimated near 60 mph toppled the Central Columbia High School concessions building.
A severe thunderstorm produced a wind gust of 58 mph at Central Columbia High School.
A severe thunderstorm producing winds estimated near 60 mph knocked down numerous trees near Shamokin.
A severe thunderstorm producing winds estimated near 60 mph knocked down several large trees in Ringtown.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires onto Pike Road at Mill Road.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires onto Rambo Hill Road at Spring Road.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires in Schuylkill Haven.
A severe thunderstorm producing winds estimated near 75 mph knocked down numerous trees and wires down along the Route 34 corridor. Some trees fell onto homes, and there was roof damage to some barns in the area.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires at North Front Street and Miller Lane.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto homes on Green Street.
A severe thunderstorm produced a wind gust of 68 mph in Grantville.
A severe thunderstorm produced quarter-sized hail near Mechanicsburg.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires along Pine Grove Road.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees across Mastersonville Road.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires onto South Charlotte Street in Manheim.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires along Park Road in East Berlin.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees across Valleybrook Drive.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees along Long Level Road south of Wrightsville.
A severe thunderstorm produced quarter-sized hail near Gettysburg.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires across Route 272 near Akron, briefly closing the roadway.
A severe thunderstorm producing winds estimated near 60 mph knocked down a large tree onto a home in Ephrata, causing significant damage to the home.
A severe thunderstorm produced quarter-sized hail near Gettysburg.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees and wires across Philadelphia Street in Hanover.
A severe thunderstorm produced quarter-sized hail west of Codorus.
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, May 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 2026-09-24. Each event’s entry at NCEI: 745515, 745516, 745517, 745518, 745519, 745520, 745525, 745526, 745527, 745528, 745529, 745530, 745531, 745504, 745532, 745533, 745558, 745506, 745534, 745535, 745536, 745537, 745538, 745540, 745542, 745544, 745546, 749091, 745551, 745553, 749094, 749095, 749096, 745554, 745555, 745560, 745556, 745568, 745569, 745570, and more.