Moist southern flow along a quasi stationary boundary drifted eastward into the evening of May 9th, 2019. That brought areas of heavy rainfall which caused flooding in southeastern Pennsylvania.
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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.
Moist southern flow along a quasi stationary boundary drifted eastward into the evening of May 9th, 2019. That brought areas of heavy rainfall which caused flooding in southeastern 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 State College, PA wrote its last area forecast discussion before the first event at May 9, 7:48 PM EST, 42 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 848 PM EDT Thu May 9 2019 .SYNOPSIS... A stalled frontal boundary south and west of the region has kept low clouds over the region today. Showers sparking out ahead of an approaching system will move across the western half of central PA this afternoon and then move eastward this evening into Friday morning. The moist southeast flow has kept cloudy and locally drizzly conditions over the region and will continue to do so through the east through tonight. Tomorrow will bring a chance of showers and thunderstorms in the morning as the warm front lifts northward into NY state, followed by a cold front swinging across Pennsylvania tomorrow afternoon that will bring scattered thunderstorms with it. High pressure will briefly pass to the north Saturday before another storm system crosses the region Sunday and Sunday night. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Southerly flow along the quasi stationary boundary continues to keep moisture over the region through the afternoon. Areas on the SE facing slopes and ridges will see patchy drizzle and light showers with upwards of a tenth of an inch of precipitation this afternoon and early evening. The front will slowly drift northward as the day progresses. The clouds through the west will slowly lift. However the showers and low topped storms moving north through the western half of the state will have trouble creeping into central PA due to the higher areas of CIN and cloudy skies and more stable air. However that should slowly erode as the evening continues which will allow the showers and storms to infiltrate the region late afternoon into the early evening. Cooler conditions still expected over the eastern half of the region with temperatures between 65-70F across the Alleghenies near to the west of Route 219. Temperatures over the far east continues to struggle to reach 60 in the northeast and should hold in the low 60s. Due to the cloudy skies and the showers, expect minimum temperatures to remain fairly warm. Ranging from the mid 50s in the Northeast to the low 60s elsewhere. The heaviest rain threat appears to be mainly confined to areas west and north of PA, however due to being on the outskirts of the rainfall, the Northwest Mountains are in the slight risk of excessive rainfall Thursday night into Friday morning. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... The warm front stays well south of the area tonight before finally lifting north on Friday. Tomorrow will be dominated by a low pressure system that will bring successive fronts tomorrow. The first will be a warm front that will finally lift northward Friday morning. This will bring showers with perhaps enough instability for scattered thunderstorms through the central mountains. Clearing skies behind the warm front should spur temperatures up into the 70s for all but the NW Mountains. That will be due to earlier FROPA and highs in the mid to upper 60s. As the Cold front crosses PA Friday morning and afternoon the model consensus indicates moderate CAPE and some favorable shear ahead of the front. SPC has all of my area in MRGL outlook for a threat of some strong storms. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Front moves south of the region Friday into and Saturday. High pressure building to the north will provide a brief period of dry weather, though it will be cooler once again, with highs again in the 50s and 60s. Next wave of low pressure quickly pushes in from the southwest by early Sunday, with another widespread episode of rain looking more and more likely. Not sure yet about any severe weather threat, as that will depend on how far back north the warm front can make it. A heavy rain threat could materialize regardless, however. The system tries to clear the region Monday, but lingering upper level trough may result in continued showers. Temperatures will remain cool. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... A slow-moving cold front over the Grt Lks will spread showers and even a possible thunderstorm into the northwest half of Pennsylvania overnight. Ahead of the front, a moist southeast flow will yield widespread mvfr cigs across central Pa, with ifr cigs possible over the higher terrain of central and northern Pa. In addition, increasing southwest winds aloft, combined with lighter southeast winds at ground level, may result in llws across the eastern half of the state overnight. Expect improving conditions Friday, as winds veer to the southwest ahead of approaching cold front. Latest SREF prob charts support many locations rising to vfr by afternoon, with lingering mvfr cigs over the northern mountains (KBFD) and Laurel Highlands (KJST). A broken line of showers and thunderstorms is likely to accompany the passage of the cold front across eastern Pa during the afternoon/evening, producing brief reductions in spots. Otherwise, expect continued improvement into Friday evening, as a drier northwest flow works in behind the front. Model output supports a high confidence of vfr conditions over most of central Pa Friday evening. However, can't rule out lingering mvfr stratocu over the high terrain from KBFD south to KJST. .Outlook... Sat...No sig wx expected. Sun...Rain/low cigs possible, mainly southern Pa. Mon...Rain/low cigs possible, especially in the morning. Tue...AM low cigs/fog possible. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && SYNOPSIS...DeVoir/Lambert NEAR TERM...DeVoir/Ceru SHORT TERM...DeVoir/Ceru LONG TERM...DeVoir/Gartner AVIATION...Fitzgerald
Hazardous Weather Outlook National Weather Service State College PA 359 AM EDT Thu May 9 2019 PAZ006-011-012-017>019-024>028-033>037-041-042-045-046-049>053- 056>059-063>066-100800- Potter-Cameron-Northern Clinton-Clearfield-Northern Centre- Southern Centre-Cambria-Blair-Huntingdon-Mifflin-Juniata-Somerset- Bedford-Fulton-Franklin-Tioga-Northern Lycoming-Sullivan- Southern Clinton-Southern Lycoming-Union-Snyder-Montour- Northumberland-Columbia-Perry-Dauphin-Schuylkill-Lebanon-Cumberland- Adams-York-Lancaster- 359 AM EDT Thu May 9 2019 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Scattered thunderstorms may produce gusty winds on Friday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ004-005-010-100800- Warren-McKean-Elk- 359 AM EDT Thu May 9 2019 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. A soaking rainfall is expected Thursday night and Friday, with local amounts in excess of one inch possible. Minor flooding of poor drainage areas is possible. Scattered thunderstorms may produce gusty winds on Friday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The Pittsburgh radar (KPBZ), 108 km away, was scanning. The volume nearest the first event began at 01:31 UTC.
1 flash flood. Local standard time, as filed.
Heavy rainfall caused flooding along Gilbert Hollow Road and caused debris to dam a drain which led to the evacuation of 21 homes along Gilbert Hollow Road. The rain and water subsided by 1144 PM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2019Every state in 2019This day in weather historyWarnings in Pennsylvania, May 2019
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: 830415.