Although this Wednesday afternoon started out with a fairly low-key development of isolated strong to severe thunderstorms in northern portions of South Central Nebraska, this convective event ended up being one of the most significant heavy rain episodes of 2013 for much of the northeast two-thirds of the 24-county area, highlighted by a small zone of 8+ inch rainfall in southeastern Greeley County. In terms of actual severe weather, this event was small in scale, featuring only a handful of quarter to golf ball size hail reports in southern Greeley and northwestern Howard counties during the late afternoon and early evening, with the largest hail stones reported four miles south of Greeley at 535 pm CDT. However, as the large hail threat diminished by sunset, heavy rainfall took over as the main story for the next several hours lasting well into Thursday morning the 3rd, as the initially isolated development in northern counties morphed into a slow-moving, southward-drifting linear mesoscale convective system (MCS). By the time all convection finally exited South Central Nebraska shortly before sunrise on the 3rd, most places generally northeast of a line from Loup City-Gibbon-Blue Hill-Superior had received at least 2-3 of rain, but with a corridor of higher amounts generally 4-6 concentrated across much of Adams, northwestern Nuckolls and southwestern Clay counties. Within these counties, just a few of the highest reported rainfall totals included 6.35 a few miles south of Juniata and 4.75 a few miles south of Trumbull. At Hastings Municipal Airport, 3.49 of the storm total of 4.13 fell on the calendar day of Oct. 3rd, shattering the previous record for highest rainfall on any given day in October (2.95 on Oct. 16, 1968). Of even greater significance, however, was the incredible amount of rain that fell mainly between 4-9pm CDT within a small portion of southeastern Greeley County. Despite limited ground-truth from the epicenter of heavy rainfall in that area, an observer five miles northwest of Wolbach measured 8.46, and radar estimates suggested that even higher amounts might have fallen roughly 4-8 miles northeast of Wolbach. Although several counties in South Central Nebraska undoubtedly experienced short-term flooding issues from this event including lowland flooding and damage to rural roads, specific flooding reports were fairly limited. However, a few known reports included water running across several county roads in southeastern Greeley County, and also water up to the hood of a vehicle on Highway 92 east of Ashton near the Sherman-Howard County line. Fortunately, a stretch of predominantly dry weather during the preceding few weeks likely mitigated more significant flooding on larger creeks and rivers. As for thunderstorm winds during this event, there were no known-instances of severe-criteria gusts, although a RAWS sensor in western Clay County clocked a near-severe gust to 54 MPH.
Taking a closer look at event timing, the initial development of localized strong to severe storms got underway within primarily Sherman, Howard, Valley and especially southern Greeley counties between 3-7 pm CDT. During these early stages, several very slow-moving to nearly stationary multicell storms dumped heavy rainfall and isolated large hail over many of the same areas. Then between 7-10 pm CDT, the initial storm clusters finally started sinking slowly southward toward the Interstate 80 corridor, while gradually expanding in coverage and elongating into a west-southwest to east-northeast linear system. From about 10 pm to 1 am CDT, the MCS propagated slowly southward across Interstate 80 and into counties along Highway 6 from near Holdrege to Geneva. During the pre-dawn hours of the 3rd, widespread convection continued drenching primarily those counties south of Interstate 80 and near/east of Highway 281, with backbuilding along the western edge of the complex resulting in the enhanced rainfall totals over Adams County and vicinity. Finally, between 6-7 am CDT, the back edge of weakening convection departed the eastern fringes of the local area, ending nearly 16 consecutive hours of thunderstorm activity within South Central Nebraska. On the synoptic scale aloft this was a fairly weakly-forced event, as South Central Nebraska resided under relatively weak west-southwest mid-upper level flow, downstream from a larger scale trough organizing over the Pacific Northwest and Northern Rockies. However, a low-level focus for convective development existed in the form of a southwest-northeast oriented cold front that roughly bisected Nebraska during the late afternoon and evening hours. The initial mid-late afternoon storms flared up near this frontal boundary, aided by forcing from a subtle shortwave trough passing through the area. During these early stages, mesoscale severe weather parameters within the local area featured fairly modest mixed-layer CAPE values of 1000-1500 J/kg and generally no more than 30 knots of 0-6 kilometer vertical wind shear. However, the combination of the weak shear environment featuring mid-upper level flow nearly parallel to the surface front, along with seasonably-high low level moisture reflected by surface dewpoints in the low-mid 60s F, fostered the slow storm movement and resultant heavy rainfall. As the night wore on, the southward expansion of the MCS was aided by the development of a south-southwesterly low level jet that ramped up to around 40 knots at 850 millibars, enhancing moisture transport into the area.

Hail in HOWARD, NEBRASKA
From 02-OCT-13 18:36:00 to 02-OCT-13 18:36:00 (CST-6)
Location: COTESFIELD
Magnitude: 1.50 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to ping pong size hail occurred. Moderate to heavy rain also occurred.

Flood in SHERMAN, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: ASHTON
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Broadcast Media

This report was posted to the KHAS-TV facebook page around midnight CDT. A KHAS viewer reported driving into flood waters on Highway 92, just east of Ashton. Water was over the hood of the vehicle and caused the vehicle to stall.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 22:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: (HSI)HASTINGS ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A rain total of 4.13 inches occurred at Hastings Municipal Airport (official Hastings rainfall total). Of this total rainfall, 3.49 inches fell on the calendar day of Oct. 3rd, which set a new Hastings daily rainfall record for any day in October, eclipsing the previous mark of 2.95 on Oct. 16, 1968. The event-total was also the second-highest two-day October rainfall on record, falling just short of 4.25 that fell on Oct. 16-17, 1968.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: JUNIATA
Property damage: 400.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 6.35 inches occurred.

Heavy Rain in GREELEY, NEBRASKA
From 02-OCT-13 14:00:00 to 03-OCT-13 01:00:00 (CST-6)
Location: WOLBACH
Property damage: 250.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 8.46 inches occurred.

Heavy Rain in HOWARD, NEBRASKA
From 02-OCT-13 15:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: FARWELL
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Public

A rainfall total of 6.60 inches occurred. This report was relayed via KHAS-TV.

Hail in GREELEY, NEBRASKA
From 02-OCT-13 16:35:00 to 02-OCT-13 16:35:00 (CST-6)
Location: GREELEY
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to golf ball size hail occurred with some rain.

Hail in GREELEY, NEBRASKA
From 02-OCT-13 17:28:00 to 02-OCT-13 17:28:00 (CST-6)
Location: GREELEY
Magnitude: 1.25 
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to half dollar size hail occurred with rain mixed in.

Heavy Rain in NUCKOLLS, NEBRASKA
From 02-OCT-13 22:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: RUSKIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.72 inches occurred.

Heavy Rain in CLAY, NEBRASKA
From 02-OCT-13 21:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: CLAY CENTER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.45 inches occurred.

Heavy Rain in THAYER, NEBRASKA
From 02-OCT-13 23:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: CARLETON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.40 inches occurred.

Heavy Rain in HAMILTON, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 06:00:00 (CST-6)
Location: HORDVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.24 inches occurred.

Heavy Rain in GREELEY, NEBRASKA
From 02-OCT-13 14:00:00 to 03-OCT-13 01:00:00 (CST-6)
Location: SCOTIA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.16 inches occurred. Penny size hail also fell around 630 pm CDT. The time of the hail is estimated by radar data and other nearby reports.

Heavy Rain in GREELEY, NEBRASKA
From 02-OCT-13 14:00:00 to 03-OCT-13 01:00:00 (CST-6)
Location: SCOTIA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.16 inches occurred.

Heavy Rain in NUCKOLLS, NEBRASKA
From 02-OCT-13 22:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: HARDY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.09 inches occurred.

Flash Flood in GREELEY, NEBRASKA
From 02-OCT-13 18:43:00 to 03-OCT-13 00:30:00 (CST-6)
Location: WOLBACH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Creeks were running full across southeastern Greeley County. Water was running across many county roads. One county road was impassable and had to be closed due to high water.

Hail in GREELEY, NEBRASKA
From 02-OCT-13 15:55:00 to 02-OCT-13 15:55:00 (CST-6)
Location: WOLBACH
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail occurred within heavy rain.

Hail in GREELEY, NEBRASKA
From 02-OCT-13 15:55:00 to 02-OCT-13 15:55:00 (CST-6)
Location: WOLBACH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Quarter size hail occurred within heavy rain.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: HASTINGS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A rain total of 4.32 inches fell.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: (HSI)HASTINGS ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A rain total of 4.27 inches occurred.

Heavy Rain in THAYER, NEBRASKA
From 02-OCT-13 23:00:00 to 03-OCT-13 06:00:00 (CST-6)
Location: DESHLER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A rain total of 4.10 inches occurred.

Heavy Rain in CLAY, NEBRASKA
From 02-OCT-13 21:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: DEWEESE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A rain total of 4.10 inches fell.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: ASSUMPTION
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 5.92 inches occurred.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: AYR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.45 inches occurred.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: PAULINE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.12 inches occurred.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: JUNIATA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 5.40 inches occurred.

Heavy Rain in NUCKOLLS, NEBRASKA
From 02-OCT-13 22:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: ANGUS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 5.12 inches occurred.

Heavy Rain in NUCKOLLS, NEBRASKA
From 02-OCT-13 22:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: LAWRENCE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 4.29 inches occurred.

Heavy Rain in ADAMS, NEBRASKA
From 02-OCT-13 20:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: ASSUMPTION
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 4.75 inches occurred.

Heavy Rain in CLAY, NEBRASKA
From 02-OCT-13 21:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: FAIRFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 4.16 inches occurred.

Heavy Rain in CLAY, NEBRASKA
From 02-OCT-13 21:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: TRUMBULL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 4.75 inches occurred.

Heavy Rain in NUCKOLLS, NEBRASKA
From 02-OCT-13 22:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: ANGUS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 4.96 inches occurred.

Heavy Rain in THAYER, NEBRASKA
From 02-OCT-13 23:00:00 to 03-OCT-13 06:00:00 (CST-6)
Location: CHESTER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.82 inches occurred.

Heavy Rain in NUCKOLLS, NEBRASKA
From 02-OCT-13 22:00:00 to 03-OCT-13 05:00:00 (CST-6)
Location: NORA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A rainfall total of 3.26 inches occurred.