For the second straight evening/overnight, widespread convection including a few severe storms affected South Central Nebraska, this time occurring on the evening of Monday the 2nd into the early morning of Tuesday the 3rd. All ground-truth reports of severe weather focused during the evening, highlighted mainly by several instances of nickel to golf ball size hail, with some of the largest stones reported near Grand Island and also near Macon in Franklin County. Half dollar size hail even fell at the NWS office just north of Hastings. The only report of severe-criteria winds consisted of estimated 60 MPH gusts between Hastings and Juniata. Compared to the preceding night, these storms dropped more concentrated swaths of heavy rain in the 2-4 range, resulting in mainly minor, short term flooding issues. The two primary swaths of heavy rain concentrated: 1) Across much of Franklin, southern Adams and northwestern Webster counties, including an NeRAIN report of 3.37 near Naponee...2) Along a narrow swath extending from near Grand Island northeastward toward Genoa, including a 24-hour total of 3.72 at Central Nebraska Regional Airport. Eventually, runoff from the southern axis of heavy rain prompted minor flooding along the Republican River, with the automated gauge near Guide Rock cresting slightly over its flood stage of 11.0 feet on the morning of the 4th.
Things got underway between 6-7 p.m. CDT, as a few corridors of northeast-southwest oriented convection rapidly blossomed in the general vicinity of a near-stationary surface front. Over the course of the next 2-3 hours, storm increased in coverage and peaked in intensity, assuming mainly quasi-linear mode, but also with a few embedded supercell structures. While the initial round of severe convection mainly affected central counties (including the Hastings and Grand Island areas), a secondary round of strong to severe activity raked across west-central and northern counties mainly between 9 p.m. and midnight CDT, dropping half dollar size hail near Lexington and producing a 56 MPH gust at Ord airport. Non-severe storms with mainly just locally-heavy rainfall lingered across portions of the area the remainder of the night, before either departing or dissipated between 5-7 a.m. CDT on the 3rd.
In the mid-upper levels, the setup was much the same as the previous night, as small-scale waves continued ejecting through the Central Plains in enhanced southwesterly flow, emanating from a large-scale trough anchored over the Northern Rockies. At the surface, the cold front which pushed through much of the area the preceding night stalled out and even retreated back to the northwest somewhat during the day and evening, providing an obvious southwest-northeast oriented focus for convection. Low-level moisture was quite high by October standards across most of South Central Nebraska, with surface dewpoints commonly in the low-mid 60s F. Around the time of peak storm intensity, mesoscale parameters featured around 1000 J/kg mixed-layer CAPE and rather stout effective deep-layer shear of 50-60 knots. Also like the previous night, storm intensity/organization was augmented by a strong southerly low level jet of 50-60 knots, evident at 850 millibars.

Hail in FRANKLIN, NEBRASKA
From 02-OCT-17 18:45:00 to 02-OCT-17 18:45:00 (CST-6)
Location: UPLAND
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in HALL, NEBRASKA
From 02-OCT-17 18:58:00 to 02-OCT-17 18:58:00 (CST-6)
Location: GRAND IS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in ADAMS, NEBRASKA
From 02-OCT-17 19:30:00 to 02-OCT-17 19:33:00 (CST-6)
Location: (HSI)HASTINGS ARPT
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Quarter to half dollar size hail was observed at NWS WFO Hastings, NE.

Hail in DAWSON, NEBRASKA
From 02-OCT-17 20:41:00 to 02-OCT-17 20:41:00 (CST-6)
Location: LEXINGTON
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DAWSON, NEBRASKA
From 02-OCT-17 20:43:00 to 02-OCT-17 20:43:00 (CST-6)
Location: LEXINGTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in ADAMS, NEBRASKA
From 02-OCT-17 19:24:00 to 02-OCT-17 19:24:00 (CST-6)
Location: JUNIATA
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Wind gusts were estimated to be near 60 MPH and were accompanied by nickel size hail.

Heavy Rain in FRANKLIN, NEBRASKA
From 02-OCT-17 06:00:00 to 03-OCT-17 06:00:00 (CST-6)
Location: NAPONEE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24-hour rainfall total of 3.37 inches was reported 2 miles southwest of Naponee.

Heavy Rain in FRANKLIN, NEBRASKA
From 02-OCT-17 06:00:00 to 03-OCT-17 06:00:00 (CST-6)
Location: NAPONEE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A 24-hour rainfall total of 3.17 inches was reported in Naponee.

Heavy Rain in FRANKLIN, NEBRASKA
From 02-OCT-17 06:00:00 to 03-OCT-17 06:00:00 (CST-6)
Location: FRANKLIN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A 24-hour rainfall total of 3.16 inches was reported 2 miles east-northeast of Franklin.

Heavy Rain in HALL, NEBRASKA
From 02-OCT-17 06:00:00 to 03-OCT-17 06:00:00 (CST-6)
Location: (GRI)GRAND IS RGNL A
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A 24-hour rainfall total of 3.72 inches was recorded at the Grand Island Central Nebraska Regional Airport, with a 48-hour total of 4.22.

Heavy Rain in NANCE, NEBRASKA
From 02-OCT-17 06:00:00 to 03-OCT-17 06:00:00 (CST-6)
Location: GENOA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 24-hour rainfall total of 3.30 inches occurred 6 miles west of Genoa.

Hail in ADAMS, NEBRASKA
From 02-OCT-17 19:24:00 to 02-OCT-17 19:24:00 (CST-6)
Location: JUNIATA
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Nickel size hail was reported along with estimated wind gusts near 60 MPH.

Hail in FRANKLIN, NEBRASKA
From 02-OCT-17 18:20:00 to 02-OCT-17 18:20:00 (CST-6)
Location: MACON
Magnitude: 1.75 
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to golf ball sized hail occurred.

Hail in HALL, NEBRASKA
From 02-OCT-17 18:22:00 to 02-OCT-17 18:22:00 (CST-6)
Location: GRAND IS
Magnitude: 1.75 
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Public

Quarter to golf ball sized hail occurred.