Scattered showers and thunderstorms developed south of a stalled frontal boundary that was draped from NW to SE across southwestern Pennsylvania. A small line of storms formed over the Pittsburgh area and pushed SE across Somerset and Bedford County.
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.
Scattered showers and thunderstorms developed south of a stalled frontal boundary that was draped from NW to SE across southwestern Pennsylvania. A small line of storms formed over the Pittsburgh area and pushed SE across Somerset and Bedford County. These storms produced considerable wind damage along the Route 30 corridor in Somerset County, but the wind damage quickly diminished as the storm continued eastward into slightly more stable air east of the Allegheny Front in Bedford County.
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 13, 3:01 PM EST, 1 hour 31 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 401 PM EDT Sun May 13 2018 .SYNOPSIS... A frontal boundary will remain over or just south of Pennsylvania right into the upcoming week. The front will keep the pattern unsettled with an almost daily chance of rain, along with an occasional mainly afternoon and evening thunderstorm. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Showers associated with the morning/weakening MCS has moved east of the I-81 corridor, and the bulk of the CWA has stayed dry through the mid afternoon hours under compensating subsidence and weak ridging with cool llvl damming and thick cloud cover across practically the entire CWA. Additional energy in the form of a compact mid to upper level short wave and nose of much higher sfc based capes of 2000-3000 J/KG will help to quickly fire off new, and strengthen existing convection moving into W-Central and SWRN PA ATTM. Within this area of best cape approaching the Laurel Highlands are EHIs of 1-1.5 M2/S2...leading to the low probability for transient supercells for the next several hours over our SW 3-4 counties along and just to the SW of the serpentine quasi stnry front. SPC upgraded (with their 1630Z update) the SW fringe of our CWA and adjacent SW PA into a slight risk of SVR TSRA late this afternoon into tonight, and noted the increasing chc for the issuance of a SVR watch within the next hour. Additional rainfall from this next round of late day/evening TSRA (on top of the 0.5 and 1.0 inch amounts that fell earlier today, will likely be enough to cause a few instances of transient, poor drainage or minor small stream flooding of low lying areas. The main threat for the minor flooding appears to be over the southern tier counties of PA (within and on the southern edge of the 925-850 mb instability gradient). WPC has a MRGL risk of excessive rainfall across much of Central and Southern PA for the 12Z Sunday through 12Z Monday period. Most likely, there will be a few streams get to bankfull or slightly out of their banks. Most likely problems will be wet basements and ponding of water on roads and in gullies. No need for any manner of flood watch at this point. Temps should remain very static through the rest of this afternoon, especially in the east where the wind will remain easterly all day. The wind will be from the south over the Laurels through 22 or 23Z, which along with significant erosion of the low clouds and shallow llvl inversion has allowed temps to jump into the low-mid 70s there. Within the expansive area of cool air damming temps remained in the 50s to near 60F (or 10-15 degrees below normal). Much weaker forcing and lack of lift tonight into early Monday means there will be more in the way of patchy showers/areas of drizzle. The wind will be light but convergent across the area with easterly flow in the east and W/SWrly flow in the west. Moisture remains high tonight, and we can't totally remove the mention of showers. But, QPF is meager. Cloud bases will slowly lower several hundred FT again tonight to shroud most of the higher ridge tops in fog. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... LI's do dip again in the SW late in the day Mon, so some TSRA are possible once again. A few more breaks will develop in the clouds on Monday, and temps should rise above normal - at this point, it appears 5 to 10F above normal. PWATs will rise to 2-3 sigma 18Z Monday-00Z Tuesday, and both GEFS and SREF sfc-based capes climb to a mean of 1200-1500 j/kg or better across much of the SW third to half of PA. So, expect another few rounds of late afternoon/evening SHRA/TSRA across much of the region, supported by SPC's marginal risk over that same area. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... Pennsylvania will be sandwiched between a large upper level low moving across northern Canada and a low moving through the Gulf of Mexico. The resulting stationary boundary will drape across the region through the midweek period. This unsettled weather will keep increasing moisture/dewpoints and above average PWATS. This suggests a daily risk for showers and thunderstorms. Areas of locally heavy rainfall are possible, with the potential for multiple rounds of convection. The specific areas most likely to receive heavy rains will likely be somewhat difficult to pin down until the short term when models begin to resolve mesoscale/convective processes. The upper low moving across the northeastern Gulf of Mexico will supply additional moisture which is projected to advect northward toward the Mid Atlantic by Wednesday. The deep moisture plume interacting with the nearly stationary west- east frontal zone could set up the potential for organized moderate to heavy rainfall later this upcoming week. Temperatures should be above seasonal climate averages next week with a muggy summertime/humid feel given dewpoints in the 60s. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... Widespread IFR to LIFR Cigs with mainly MVFR to VFR vsbys are expected for the rest of today, and a nearly stationary frontal boundary will stay along or just to the south of the PA/MD border through Monday before temporarily lifting north over the Commonwealth on Tuesday. High resolution convective allowing models show the next round (or few) of showers/scattered TSRA developing across NE Ohio and SW/WCentral PA in the next few hours and moving from about 280 deg...along and to the north of the aforementioned sfc frontal boundary. TSRA Impacts will be includes for all TAF sites except for KBFD and KIPT that are indicated to stay stable enough at the sfc and aloft to support deep updrafts. Expects cigs to some back down early tonight and settle in the IFR through VLIFR range by...or shortly after midnight EDT. Outlook... Mon...AM rain/low cigs possible. PM thunderstorm impacts possible - mainly across the southwestern third of Pa. Tue-Thu...AM fog possible. Scattered PM thunderstorm impacts likely Tuesday afternoon/early Tuesday evening, and still possible Wednesday and Thursday afternoon/evening, mainly across the southern half of PA. && .HYDROLOGY... The static Bermuda high and W-E frontal boundary near-overhead will make it a very wet period this week, as juicy tropical air is pushed north and over a stubborn, nearly stationary frontal boundary that will be located near, or just south of the Mason/Dixon line. Gradually wetter soil will make it easier for flooding to occur through the week. At this point, no great/widespread threat for flooding exists, so a flood watch is not anticipated. But, the approach of a quasi- tropical system later in the week may ramp up flooding chances. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Dangelo/Lambert LONG TERM...Ceru/Steinbugl AVIATION...Lambert HYDROLOGY...
Hazardous Weather Outlook National Weather Service State College PA 430 PM EDT Sun May 13 2018 PAZ004>006-010>012-017>019-027-028-037-041-042-045-046-049>053- 056>059-063>066-142030- Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield- Northern Centre-Southern Centre-Mifflin-Juniata-Tioga- Northern Lycoming-Sullivan-Southern Clinton-Southern Lycoming-Union- Snyder-Montour-Northumberland-Columbia-Perry-Dauphin-Schuylkill- Lebanon-Cumberland-Adams-York-Lancaster- 430 PM EDT Sun May 13 2018 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. Scattered strong to severe thunderstorms with gusty winds and isolated instances of large hail are possible Tuesday afternoon and evening, especially across the region near and to the south of Interstate 80. Additionally, minor flooding problems may develop throughout poor drainage areas, and along small creeks and streams. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ033-034-142030- Somerset-Bedford- 430 PM EDT Sun May 13 2018 ...SEVERE THUNDERSTORM WATCH 86 IN EFFECT UNTIL 11 PM EDT THIS EVENING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Severe Thunderstorm Watch. A few strong to severe thunderstorms with gusty winds are possible late this afternoon and evening. Additionally, some minor flooding problems are possible throughout poor drainage areas, and also along small creeks and streams. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Scattered strong to severe thunderstorms with gusty winds and isolated instances of large hail are possible again Monday and Tuesday afternoon and evening. Additionally, minor flooding problems may develop throughout poor drainage areas, and along small creeks and streams. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ024>026-035-036-142030- Cambria-Blair-Huntingdon-Fulton-Franklin- 430 PM EDT Sun May 13 2018 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. A few strong to severe thunderstorms with gusty winds are possible into the evening. Additionally, some minor flooding problems are possible throughout poor drainage areas, and also along small creeks and streams. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Scattered strong to severe thunderstorms with gusty winds and isolated instances of large hail are possible again Monday and Tuesday afternoon and evening. Additionally, minor flooding problems may develop throughout poor drainage areas, and along small creeks and streams. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1157 AM EDT SUN MAY 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0725 PM TSTM WND DMG 1 WNW RAWLINSVILLE 39.89N 76.29W
05/12/2018 LANCASTER PA 911 CALL CENTER
TREES AND WIRES DOWN
&&
EVENT NUMBER CTP1801783
TYBURSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1210 PM EDT SUN MAY 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0702 PM TSTM WND DMG WINDSOR 39.92N 76.58W
05/12/2018 YORK PA 911 CALL CENTER
TREES AND WIRES DOWN ON CRAWLEY ROAD
&&
EVENT NUMBER CTP1801784
TYBURSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1212 PM EDT SUN MAY 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0720 PM TSTM WND DMG ADAMSVILLE 39.89N 76.62W
05/12/2018 YORK PA 911 CALL CENTER
WIRES DOWN AND TREE HANGING OVER ROADWAY. DAIRYLAND
ROAD
&&
EVENT NUMBER CTP1801785
TYBURSKIThe Pittsburgh radar (KPBZ), 104 km away, was scanning. The volume nearest the first event began at 21:33 UTC.
11 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm producing winds estimated near 80 mph knocked down trees onto a home in the 200 block of Tipton Road west of Gray.
A severe thunderstorm producing winds estimated near 80 mph destroyed a large machine shed on Saint Clair Drive west of Gray.
A severe thunderstorm producing winds estimated near 60 mph knocked down numerous trees near Gray.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees along Watson Avenue north of Acosta.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees along Route 403 south of Hooversville.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees in the vicinity of Slick Road, Wilbur Road and Old Forbes Road east of Stoystown.
A severe thunderstorm producing winds estimated near 70 mph knocked down several power lines in a field near the entrance to Indian Lake on Huckleberry Highway.
A severe thunderstorm producing winds estimated near 60 mph knocked down a large tree onto wires near the Seven Springs Golf Course, partially blocking the roadway.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree and wires near the former site of the Ship Hotel on Route 30.
A severe thunderstorm producing winds estimated near 60 mph knocked down and snapped trees along Brant Hollow Road west of Buffalo Mills.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree and blocked Teaberry Road near the intersection with Buck Falls Road.
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: 745492, 745493, 745494, 745495, 745496, 745497, 745498, 745499, 745500, 745501, 745502.