The record
Everything the slot carries, as measured. Series arrays are drawn above and listed here in full.
| Event typeevent_type | Heavy Rain |
|---|---|
| NOAA NCEI event IDncei_event_id | 720,604 |
| Episode IDepisode_id | 118,429 |
| Begin UTCbegin_utc | 2017-08-15T12:00:00+00:00 |
| End UTCend_utc | 2017-08-16T12:00:00+00:00 |
| Statestate | NEBRASKA |
| County/zone typecz_type | C |
| County/zone namecz_name | VALLEY |
| Latitudelat | 41.680 |
| Longitudelon | -99.136 |
| End latitudeend_lat | 41.680 |
| End longitudeend_lon | -99.136 |
| Deaths directdeaths_direct | 0 |
| Deaths indirectdeaths_indirect | 0 |
| Injuries directinjuries_direct | 0 |
| Injuries indirectinjuries_indirect | 0 |
| Damage propertydamage_property | 0.00K |
| Damage cropsdamage_crops | 0.00K |
| Weather forecast office sourcewfo_source | CoCoRaHS |
| Episode narrativeepisode_narrative | Between the afternoon of Tuesday the 15th and the morning of Wednesday the 16th, roughly the northern half of this 24-county South Central Nebraska area saw its most significant heavy rain and localized flooding event of 2017, along with a smattering of severe storms (including one that pounded the Fullerton area with tennis ball to baseball size hail). Focusing first on the heavy rain and flooding, most areas north of a line from Kearney-Hastings-York measured at least 2-4 per NWS observers/CoCoRaHS/ radar estimation, with localized pockets of 5-7. Some of the overall-heaviest rain targeted the following three areas: 1) Much of Polk County (including a whopping 8.37 a few miles northeast of Osceola and 6.95 in town)...2) Much of Nance County (radar estimates of a widespread 3-5)...3) A roughly 10-mile wide corridor running from the north side of Hastings to around Aurora (widespread 3-5 and up to 6.70 near Phillips). Of particular note, at Osceola the official total of 6.95 set a new all-time 24-hour record for the 122 year-history of the station!||While some of this rain was actually much-needed/appreciated, various flooding issued ensued across several counties, affecting not only numerous rural roads and agricultural areas, but also several creeks and rivers, including: 1) Big Blue River, Clear Creek and Davis Creek in Polk County...2) Lincoln Creek and Beaver Creek in Hamilton and York counties...3) West Fork Big Blue River mainly between northwestern Clay and southern Hamilton counties. Most flooding (especially outside of Polk County) was relatively minor and confined to typical flood-prone areas, but issues persisted at least 36-48 hours in some places. Of all local counties, Polk County bore the brunt of flooding impacts, including: several rural roads damaged and impassable for at least few days, and fairly widespread flooding along the Davis Creek within Osceola. ||While thunderstorms were widespread during this roughly 15-hour convective event, the majority of them were sub-severe. Most severe storms occurred fairly early in the event (mainly 4-8 p.m. CDT) and yielded primarily large hail. One of the hardest-hit areas was in/near Fullerton, where stones up to baseball size fell. Elsewhere, quarter to ping pong ball size was reported in parts of Sherman, Howard, Nance and Merrick counties. There were only a few ground-truth reports of estimated severe winds, including 60-70 MPH near Loup City during the afternoon and 60 MPH in Cambridge late in the night along an invading squall line. ||Looking closer at timing, a few strong to marginally severe storms actually brushed northern parts of the area during the morning/early afternoon. However, the main event got underway near and north of the Nebraska Highway 92 corridor between 3:30-5:30 p.m. CDT as fairly isolated/intense cells erupted along a northward-shifting warm front/retreating outflow boundary. Over the next several hours, the severity of storms gradually waned, but the coverage of convection and heavy rain greatly increased as a strengthening low level jet interacted with a southward-drifting, west-east oriented outflow boundary. Through midnight CDT, the vast majority of convection focused near and north of the Interstate 80 corridor. Then after midnight, another area of storms pushed in from the west in the form of a northeast-southwest oriented squall line, but this activity was largely sub-severe as it crossed all of South Central Nebraska. By daybreak on the 16th, only an area of lighter stratiform rain remained, before finally departing the eastern fringes of the local area by mid-morning. ||Turning to the meteorological background behind this event, the primary factors were: 1) the presence of a very moist airmass characterized by surface dewpoints between the mid 60s-low 70s F...2) a generally west-oriented surface front stretched near the Interstate 80 corridor...3) A southerly low level jet of 30-40 knots ramping up after dark into the frontal zone. In the mid-upper levels, several small-scale disturbances were passing through the region, downstream of a primary trough axis advancing out of the Central Rockies. Around the time of the most intense afternoon storms, mixed-layer CAPE averaged 2000-3000 J/kg, but deep-layer wind shear held at-or-below 30 knots, fostering slow storm motions and heavy rainfall. |
| Event narrativeevent_narrative | A 24-hour precipitation amount of 3.62 inches was recorded 6 miles west of Elyira. |
| Yearyear | 2,017 |
Provenance
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