Primarily during the daylight hours on Tuesday the 1st, a pronounced swath of heavy rain targeted much of Thayer and southeastern Fillmore counties, prompting various instances of mainly minor flooding that persisted into the afternoon of the 2nd before water receded appreciably. Official 24-hour-or-less rain totals featured: 4.65 four miles east of Ohiowa, 4.25 at Hebron airport, 3.81 on the north side of Hebron and 3.39 five miles south-southwest of Deshler. A few specific instances of flooding (per Thayer County emergency management) included: a few inches of water running over parts of Highway 81 south of Belvidere and also water over a small portion of Highway 53 just south of Alexandria. Convection remained sub-severe throughout the day (not accompanied by large hail or damaging winds). Elsewhere in South Central Nebraska (outside of Thayer/southeastern Fillmore/southeastern Nuckolls counties) rain amounts were considerably lower, with most places averaging under 1. As one final side-note: this ended up being the final flood event of 2019 within South Central Nebraska, capping off an incredibly active/damaging year of flooding.
Breaking down the timing and meteorological background of this event, it's first worth noting that antecedent conditions were conducive for flooding, as most of Thayer/southeastern Fillmore counties had just received 2.50-4.00 inches of rain during the final 10 days of September (and as much as 6.73 at Hubbell). Getting back to this October 1st event, steady rain first moved into the area around sunrise, with particularly the 10 a.m. through 3 p.m. CDT time frame featuring a nearly non-stop stream of moderate to heavy rain. Lighter rain persisted into the late afternoon/early evening, with nearly all precipitation ending for the night by 8 p.m. CDT. In the mid-upper levels, this was a favorable setup for excessive rainfall and training convection. Broad southwesterly flow and embedded, subtle disturbances (out ahead of a large-scale trough over the Northern Rockies) aligned almost directly atop a southwest-northeast oriented surface front stretched from northwest KS to southwest IA. Along this surface boundary, dewpoints in the Thayer County area averaged well into the 60s-low 70s F through most of the day, supporting stout precipitable water values around 2.

Heavy Rain in FILLMORE, NEBRASKA
From 01-OCT-19 06:00:00 to 02-OCT-19 06:00:00 (CST-6)
Location: OHIOWA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24-hour rainfall total of 4.65 inches occurred 4 miles east of Ohiowa. Most of this rain fell before 8 pm CDT on Oct. 1st.

Flood in THAYER, NEBRASKA
From 01-OCT-19 13:00:00 to 02-OCT-19 15:00:00 (CST-6)
Location: BYRON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported flooding about 2 miles south-southwest of Belvidere, with a few inches of water over one southbound lane and one northbound lane of Highway 81 near mile marker 16. Water was also reported to be over portions of Highway 53 just south of Alexandria and over rural county Road E between Road 5200 and 5300. Rainfall totals included 4.65 inches by a CoCoRaHS observer located 4 miles east of Ohiowa, 4.25 inches at the Hebron Airport and 3.81 inches by a cooperative observer in Hebron.

Heavy Rain in THAYER, NEBRASKA
From 01-OCT-19 06:00:00 to 02-OCT-19 06:00:00 (CST-6)
Location: HEBRON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A 24-hour rainfall total of 3.81 inches occurred in Hebron. Most of this rain fell before 8 pm CDT on Oct. 1st.

Heavy Rain in THAYER, NEBRASKA
From 01-OCT-19 06:00:00 to 02-OCT-19 06:00:00 (CST-6)
Location: DESHLER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24-hour rainfall total of 3.39 inches occurred five miles south-southwest of Deshler. Most of this rain fell before 8 pm CDT on Oct. 1st.

Heavy Rain in THAYER, NEBRASKA
From 01-OCT-19 00:00:00 to 01-OCT-19 23:59:00 (CST-6)
Location: HEBRON ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Hebron airport AWOS measured a calendar-day rainfall total of 4.25 inches, most of which fell between sunrise and 8 PM CDT.