Low pressure over the Ohio Valley allowed southeast winds out ahead of the storm system to draw in deep Atlantic moisture across Eastern Pennsylvania. This combined with an upper level disturbance sweeping through the area produced widespread moderate to heavy rainfall.
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 BGM wrote it up.
Low pressure over the Ohio Valley allowed southeast winds out ahead of the storm system to draw in deep Atlantic moisture across Eastern Pennsylvania. This combined with an upper level disturbance sweeping through the area produced widespread moderate to heavy rainfall. This rain came on the heels of a heavy rain day three days prior, making it easier for additional flash flooding to develop.
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 Binghamton, NY wrote its last area forecast discussion before the first event at Oct 29, 7:02 PM EST, 1 hour 50 minutes earlier.
Area Forecast Discussion National Weather Service Binghamton NY 802 PM EDT Fri Oct 29 2021 .SYNOPSIS... Rain showers are moving into the area this afternoon, and will continue through tonight. Scattered showers are expected Saturday, possibly lingering into Sunday. Temperatures will trend cooler early next week. && .NEAR TERM /THROUGH SATURDAY NIGHT/... Drier air continues to hang in tough across areas from I-81 eastward with some virga being picked up on radar. As a result, timing of the showers looks a little slower for these locations tonight. Still a few rounds of rainfall are anticipated. Rainfall amounts so far in the watch area are from 1/4 to 1/2 inch. The HRRR and Hires NAM both bring the heaviest rainfall during the mid and late evening hours with the forecasted totals on track. Right now some spots in Steuben county are approaching 50% of 3/6 hr FFG. So this amount of rainfall still has the potential to produce some flooding. Previous discussion below. 200 PM Update... Clouds are overspreading in the area with light rain finally starting to work into the western Twin Tiers. A vertically stacked low continues to slowly move northward through the Ohio valley. An occluded front extends from the center of the cyclone (approximately over Ohio/WV/northern KY) eastward to the mid- Atlantic coast. The satellite-derived total precipitable water product indicates a plume of PWATs up to 1-1.5in extending inland towards the center of the low, courtesy of a strengthening low-level jet that is helping us tap into some Atlantic moisture. Models continue to move the main area of steady, moderate to locally-heavy rain through rather quickly this evening. That, along with wind shadowing/downsloping east of the Poconos- Catskills, is supporting the continued downtrending of rainfall expectations for areas along and east of I-81. Expect totals generally under an inch for most of the area, with the burnt of the activity between 00Z and 06Z. That said, steadier, occasionally heavier rainfall will be possible for a longer duration west of I-81 and south of the Finger Lakes tonight. The axis of deeper moisture pivots westward as the low continues to slowly move northward. Meanwhile, the low level jet will cause orographic enhancement as it upslopes against the Allegheny plateau. Thus, rainfall amounts could exceed an inch for the southern Finger Lakes, as well as Steuben, Chemung, and Bradford counties These areas are already very wet and sensitive to additional rainfall; new rain will almost immediately run off into creeks/small streams. That is where there is a bit more concern for a somewhat organized flooding potential, compared to a more marginal threat elsewhere. A Flash Flood Watch has been issues for Steuben, Bradford, and Chemung counties. The stacked low will continue its northward track, moving into western NY and PA into early Saturday. This more northerly than northeasterly track means a dry slot aloft is likely to lift over our region Saturday. Showers can still be expected, but they will tend to be scattered/on- and- off and with limited amounts. Responses to the heavier rainfall, from overnight, will still be ongoing for the main stem rivers. There is a small chance of a couple river points going back to near minor flood stage, but most will stay below. Meanwhile, the persistently high water levels on Cayuga and Onondaga Lake will continue. After lows of mostly 40s tonight, highs of 50s-near 60 are anticipated for Saturday. Stray showers continue through Saturday night with the upper low directly overhead. Chances will be better across our northeastern zones as a low closes off along the mid Atlantic coast and quickly tracks into New England by early Sunday morning. Otherwise, expect lows to drop back into the mid and upper 40s under cloudy skies. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... 315 PM Update: Upper level troughing will slowly lift northeast on Sunday (Halloween), with most of the steadier rainfall moving out of the far eastern counties early in the morning. While this may be followed by a few breaks of sunshine, it'll be brief, with cyclonic flow aloft and weak cool advection with winds off the Great Lakes promoting increased cloud cover and some spotty light showers or sprinkles again in the afternoon as a weak shortwave trough rotates through. Showers will diminish again around sunset, and while a brief shower can't be completely ruled out in the evening, it will be mostly dry, with seasonal temperatures. An upper trough moving across southern Ontario into Quebec will drop a weak cold front through the area late Sunday night, with additional light showers possible starting after midnight, mainly west of I-81. The front itself will be near the Hudson Valley by Monday morning, with slightly cooler and drier air spreading across the area in its wake. Partly Sunny skies will prevail for most areas on Monday, except for parts of Oneida County, where lake effect clouds will linger. && .LONG TERM /TUESDAY THROUGH FRIDAY/... 315 PM Update: Most of the Northeast and Mid Atlantic will be on the edge of longwave troughing persisting across eastern Canada through the period. This will keep somewhat cooler than normal temperatures in place (highs in the upper-40s to lower-50s, versus the average of middle to upper 50s). No significant precipitation is expected, but occasional light showers are possible as a few weak disturbances roll by. The first one arrives late Tuesday, with lake effect showers lingering in its wake (mainly west of I-81 in NY). Another sharper shortwave rolls through on Wednesday, bringing the chance of showers to most areas (including NE PA) before Noon, with lake effect lingering in NY through the afternoon. Precip may be a rain/snow mix Tuesday night into Wednesday morning, but coverage and QPF will be low, with minimal impacts expected. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... Rain is moving through the region from SW to NE this evening with intermittent IFR restrictions likely at all terminals as it moves through. ELM, ITH, AVP, and BGM will be impacted between now and 3z while it will take till 2 to 3z to get to SYR and RME with restrictions. A few rain showers ahead of the line could impact RME and SYR but will likely not result in any restrictions with how dry the low levels are ahead of the rain. A strong low level jet will also be associated with the rain with BGM, RME, and AVP having the best chance of reaching LLWS criteria. Behind the rain, low stratus will keep Fuel alternate to border line IFR conditions at all terminals with continued rain showers at times through the late morning. With day time heating, cigs will rise a bit but VFR conditions are unlikely at most terminals but AVP where the added benefit of downsloping will help raise the cigs by the late afternoon. Outlook... Saturday afternoon through Saturday night...Restrictions likely as low pressure system finishes moving through the region with scattered showers and fuel alternate to at times IFR ceilings. Sunday through Sunday night...Scattered rain showers and occasional restrictions possible; mainly Central NY terminals. Monday through Monday night...Mainly VFR. Tuesday through Wednesday...Restrictions possible in passing showers, which may mix with snow during the overnight hours. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Flash Flood Watch until 5 AM EDT Saturday for PAZ038. NY...Flash Flood Watch until 5 AM EDT Saturday for NYZ022-024. && SYNOPSIS...HLC NEAR TERM...HLC/MDP/MWG SHORT TERM...MPH LONG TERM...MPH AVIATION...AJG
Hazardous Weather Outlook National Weather Service Binghamton NY 327 PM EDT Fri Oct 29 2021 NYZ009-015>018-023-025-036-037-044>046-055>057-062-PAZ039-040-043- 044-047-048-072-301930- Northern Oneida-Yates-Seneca-Southern Cayuga-Onondaga-Schuyler- Tompkins-Madison-Southern Oneida-Cortland-Chenango-Otsego-Tioga- Broome-Delaware-Sullivan-Susquehanna-Northern Wayne-Wyoming- Lackawanna-Luzerne-Pike-Southern Wayne- 327 PM EDT Fri Oct 29 2021 This Hazardous Weather Outlook is for central New York and northeast Pennsylvania. .DAY ONE...This afternoon and tonight. Another round of rain is moving in this afternoon, and will continue through the night. There is a potential for periods of heavy rain late tonight, which could lead to localized flooding. Areas that already experienced flooding earlier this week will be more sensitive to any additional heavy rain. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. NYZ022-024-PAZ038-301930- Steuben-Chemung-Bradford- 327 PM EDT Fri Oct 29 2021 ...FLASH FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT... This Hazardous Weather Outlook is for central New York and northeast Pennsylvania. .DAY ONE...This afternoon and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flash Flood Watch. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BINGHAMTON NY
851 PM EDT FRI OCT 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0845 PM HEAVY RAIN CANISTEO 42.27N 77.60W
10/29/2021 M1.30 INCH STEUBEN NY TRAINED SPOTTER
STILL HEAVY RAIN FALLING.
&&
AJGPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BINGHAMTON NY
928 PM EDT FRI OCT 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 PM FLOOD BRANCHPORT 42.60N 77.15W
10/29/2021 YATES NY 911 CALL CENTER
FLOODED BASEMENT ON AUMICK ROAD.
&&PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE BINGHAMTON NY
941 PM EDT FRI OCT 29 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0937 PM FLOOD 3 E BURLINGTON 41.78N 76.56W
10/29/2021 BRADFORD PA 911 CALL CENTER
6-10 INCHES OF WATER CROSSING ROUTE 6 IN
BURLINGTON TOWNSHIP.
&&
AJGThe national radar mosaic for the moment the first event began.
1 flash flood. Local standard time, as filed.
Flash flooding was occurring across U.S. Route 6 to the east of Burlington.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2021Every state in 2021This day in weather historyWarnings in Pennsylvania, October 2021
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: 989864.