Thunderstorms developed ahead of and along a strong cold front the afternoon and evening of the 20th. While heavy rains of 2 to 4 inches in 24 hours were reported across the region, only isolated flash flooding was reported.
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 PBZ wrote it up.
Thunderstorms developed ahead of and along a strong cold front the afternoon and evening of the 20th. While heavy rains of 2 to 4 inches in 24 hours were reported across the region, only isolated flash flooding was reported. A few thunderstorms became severe, with a wind gust estimated near 80 MPH near Dunbar, in Fayette county Pennsylvania.
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 Pittsburgh, PA wrote its last area forecast discussion before the first event at Oct 20, 5:07 AM EST, 37 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 607 AM EDT Thu Oct 20 2016 .SYNOPSIS... Low pressure and a crossing cold front will bring widespread rain to the region from late today into Friday. Much cooler weather will follow for the weekend. && .NEAR TERM /THROUGH TONIGHT/... Updated for continuing rain and thunderstorms north of I-80. This activity will continue to lift northward over the next few hours as the warm sector advances northward a bit. Rest unchanged for now. Previous discussion... The warm front will continue to lift north today as a midlevel trough continues to dig in the Mississippi Valley...putting a good portion of the CWA in the warm sector. This will suppress precipitation across much of the area through at least midday, while some showers remain possible mainly north and west of Pittsburgh. As low pressure rides up the Ohio Valley later today along the advancing cold front, showers and some thunderstorms will advance across the area mainly after 18Z. Likely and low-end categorical PoPs reappear by 00Z. Lift and moisture is maximized tonight with frontal passage and the approach of the still-digging and negatively-tilting shortwave, leading to near 100 PoPs. Going to hold off on the issuance of any flood watches for now until areas of best rainfall can be ascertained later today. However, amounts will need to be monitored along the aforementioned heavy rain band from this morning. An additional one to two inches may be seen in general from late afternoon into tomorrow morning, and we may not be able to totally rule out isolated flooding issues. Will mention in HWO. Also of concern is marginal risk of severe storms across the region as outlined by SPC. Increasing speed shear is noted on model soundings for the afternoon, with 40 knots of flow at 700 mb. Lack of deep instability may be a limiting factor in a more significant severe threat. Still, isolated strong to even damaging gusts are a possibility, with large hail a lesser threat. Will also mention this in HWO. Increased high temperatures today, especially in the southeast, with the influence of the warm sector. Readings in the 80s appear likely here. Little change to lows tonight...mainly in the upper 40s to the mid 50s. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... The frontal precipitation will drift eastward Friday morning with additional showers developing behind the boundary in the strong cold air advection and passage of the upper level trough axis. Much colder weather will follow for the weekend as the upper trough develops over the Eastern CONUS. Scattered showers will remain in the forecast through at least Saturday morning, with focus shifting to the north and ridge zones, as cold advection continues and shortwaves in northwest flow traverse the area. By Saturday afternoon, the much drier air aloft, which will work to suppress inversion heights, will eventually make it closer to the surface, bringing and end to any lingering showers. Still expect to see a good deal of cu over the area Saturday with the cold pool aloft remaining anchored over the area. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Dry, but seasonably cool conditions will return Sunday as warmer air slowly works back into the area. Ensemble solutions continue to push a weak front through the area sometime on Monday, which may provide another risk for scattered showers. High pressure builds in for the remainder of the long term. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... Rain and thunderstorms are currently mainly north of I-80, and are expected to lift northward over the next few hours as the warm sector becomes more established. Most terminals will remain VFR through the morning hours, save for FKL early and possibly DUJ if a few showers can survive. Winds may gust to between 15 and 20 knots this afternoon from the southwest. Conditions will deteriorate overnight as numerous showers and a few thunderstorms develop from west to east. Expect all terminals to drop through MVFR this evening to IFR tonight, as rain is expected to be moderate to possibly heavy at times. While visibility may fluctuate a bit, ceilings will stay at IFR through 12Z, with LIFR possible especially north and west of PIT. .OUTLOOK /THURSDAY NIGHT THROUGH MONDAY/... Periodic restrictions are expected through Saturday as low pressure and subsequent upper troughing cross the area. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 440 AM EDT THU OCT 20 2016 MDZ001-OHZ049-057>059-068-069-PAZ007>009-013-021-023-029-031-073>076- WVZ002>004-012-021-509>514-210845- GARRETT-HARRISON-MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-MERCER- VENANGO-FOREST-LAWRENCE-ALLEGHENY-INDIANA-WASHINGTON-GREENE- WESTMORELAND-WESTMORELAND RIDGES-FAYETTE-FAYETTE RIDGES-BROOKE-OHIO- MARSHALL-WETZEL-MARION-MONONGALIA- RIDGES OF EASTERN MONONGALIA AND NORTHWESTERN PRESTON-PRESTON- EASTERN PRESTON-WESTERN TUCKER-EASTERN TUCKER- 440 AM EDT THU OCT 20 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MARYLAND...EAST CENTRAL OHIO...NORTHWEST PENNSYLVANIA...SOUTHWEST PENNSYLVANIA...WEST CENTRAL PENNSYLVANIA...WESTERN PENNSYLVANIA...NORTHERN WEST VIRGINIA AND NORTHERN PANHANDLE OF WEST VIRGINIA. .DAY ONE...TODAY AND TONIGHT. THERE IS A RISK OF ISOLATED SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. DAMAGING WINDS ARE THE PRIMARY THREAT...WITH LARGE HAIL ALSO A POSSIBILITY. ONE TO TWO INCHES OF RAINFALL IS EXPECTED FROM LATE TODAY INTO FRIDAY MORNING, WITH ISOLATED HIGHER TOTALS. LOCALIZED FLOODING IS A POSSIBILITY. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY. THE THREAT OF HEAVY RAIN AND ISOLATED FLOODING MAY CONTINUE INTO FRIDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. OHZ039>041-048-050-PAZ014>016-020-022-WVZ001-210845- TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-JEFFERSON-BUTLER-CLARION- BEAVER-ARMSTRONG-HANCOCK- 440 AM EDT THU OCT 20 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL OHIO...WEST CENTRAL PENNSYLVANIA...WESTERN PENNSYLVANIA AND NORTHERN WEST VIRGINIA. .DAY ONE...TODAY AND TONIGHT. THERE IS A RISK OF ISOLATED SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. DAMAGING WINDS ARE THE PRIMARY THREAT...WITH LARGE HAIL ALSO A POSSIBILITY. ONE TO TWO INCHES OF RAINFALL IS EXPECTED FROM LATE TODAY INTO FRIDAY MORNING, WITH ISOLATED HIGHER TOTALS. LOCALIZED FLOODING IS A POSSIBILITY. THIS IS PARTICULARLY TRUE IN AREAS THAT RECEIVED HEAVY RAINFALL LATE WEDNESDAY NIGHT. IF THE THREAT INCREASES...A FLASH FLOOD WATCH MAY BE NECESSARY. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY. THE THREAT OF HEAVY RAIN AND ISOLATED FLOODING MAY CONTINUE INTO FRIDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PITTSBURGH PA 211 AM EDT THU OCT 20 2016 PAZ014-020-021-200645- ALLEGHENY-BUTLER-BEAVER- 211 AM EDT THU OCT 20 2016 ...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN BEAVER... SOUTHWESTERN BUTLER AND NORTHERN ALLEGHENY COUNTIES... AT 210 AM EDT...A STRONG THUNDERSTORM WAS LOCATED OVER ALIQUIPPA... MOVING EAST AT 40 MPH. WIND GUSTS UP TO 50 MPH ARE POSSIBLE WITH THIS STORM. LOCATIONS IMPACTED INCLUDE... PENN HILLS...ROSS TOWNSHIP...MCCANDLESS TOWNSHIP...CRANBERRY...MOON TOWNSHIP...FRANKLIN PARK...ALIQUIPPA...MONACA...SHALER TOWNSHIP... PLUM...HAMPTON TOWNSHIP AND ROBINSON TOWNSHIP. THIS INCLUDES THE FOLLOWING HIGHWAYS... PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 22 AND 52. INTERSTATE 79 IN PENNSYLVANIA BETWEEN MILE MARKERS 64 AND 83. PARKWAY NORTH BETWEEN MILE MARKERS 6 AND 13. TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS. LAT...LON 4051 8038 4069 8040 4084 7980 4049 7977 TIME...MOT...LOC 0610Z 260DEG 36KT 4062 8028 CL
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
236 AM EDT THU OCT 20 2016
PAZ021-029-200715-
ALLEGHENY-WASHINGTON-
236 AM EDT THU OCT 20 2016
...STRONG WIND GUSTS WILL AFFECT CENTRAL WASHINGTON AND SOUTHERN
ALLEGHENY COUNTIES...
AT 233 AM EDT...AN OUTFLOW OF GUSTY WINDS WAS LOCATED OVER NORTH
SIDE PITTSBURGH MOVING SOUTHEAST AT 35 MPH.
WINDS IN EXCESS OF 40 MPH ARE POSSIBLE WITH THIS LINE.
LOCATIONS IMPACTED INCLUDE...
PITTSBURGH...PENN HILLS...MOUNT LEBANON...BETHEL PARK...
MONROEVILLE...MCMURRAY...MCKEESPORT...WASHINGTON...CANONSBURG...
GASTONVILLE...SHALER TOWNSHIP AND PLUM.
THIS INCLUDES THE FOLLOWING HIGHWAYS...
INTERSTATE 70 IN PENNSYLVANIA BETWEEN MILE MARKERS 7 AND 38.
PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 53 AND 58.
INTERSTATE 79 IN PENNSYLVANIA BETWEEN MILE MARKERS 50 AND 61...AND
BETWEEN MILE MARKERS 27 AND 49.
PARKWAY NORTH BETWEEN MILE MARKERS 1 AND 4.
LAT...LON 4039 7975 4039 7977 4031 7979 4029 7978
4028 7980 4026 7979 4024 7981 4023 7979
4020 7987 4018 7985 4016 7986 4016 7990
4013 7988 4001 7998 4013 8046 4049 8009
4049 7970 4043 7970
TIME...MOT...LOC 0633Z 302DEG 32KT 4045 8001The Pittsburgh radar (KPBZ), 84 km away, was scanning. The volume nearest the first event began at 10:43 UTC.
8 thunderstorm wind, 2 flash flood. Local standard time, as filed.
Law enforcement reported flash flooding on East Main Street in Sharpsville.
A trained spotter reported Colt Road near State Route 18 washed out.
Law enforcement reported trees down.
The public reported several large trees down, with damage reported to a soffit on one home.
An NWS storm survey found straight line wind damage, with 30 large trees down, and roof damage to a home and a barn nearby. The estimated highest gust was near 80 MPH.
The media reported a large tree down.
Law enforcement reported multiple trees down.
Law enforcement reported numerous trees down.
Law enforcement reported numerous trees down.
The media reported numerous trees and wires down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2016Every state in 2016This day in weather historyWarnings in Pennsylvania, October 2016
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: 659986, 659987, 659988, 659989, 659990, 659991, 659992, 659993, 659994, 659995.