Sept. 2018: Weather/Climate Review For South Central NE/North Central KS

Recap of September 2018 Weather for the 30-county NWS Hastings Coverage Area:

September 2018 Precipitatio

- Rainfall: Compared to the preceding few months, September rainfall featured a bit more of a disparity between the highest and lowest monthly amounts. That being said, for the 30 counties as a whole, roughly 70% of the area was at least slightly above normal, especially southeast of a line from Cambridge-Kearney-Wolbach, and including most of north central KS. Meanwhile, the roughly 30% of the area that saw below normal monthly rainfall concentrated northwest of the aforementioned line (including counties such as Valley/Sherman/northern Buffalo), along with a portion of central and western Phillips County KS. Another unique aspect of Sep. 2018 rainfall was that the vast majority of it fell in the first 5 days of the month, with predominantly dry conditions thereafter. More specifically, much of the area received 70-90% of its monthly total in the first five days! Per dozens of NWS/CoCoRaHS observers, a few of the highest-known September totals (roughly 300% of normal!) featured: 8.20" southeast of Deweese, 8.11" southeast of Lawrence, and 8.10" at Davenport and near Fairfield. On the much drier, slightly below normal side of things, a few of the lowest monthly amounts included: 1.24" at Cambridge and Ord, 1.25" at Ravenna and 1.42" at Logan KS.

As for short-term/24-hour-or-less rain totals: a few of the highest amounts from CoCoRaHS/NeRAIN observers featured 4.90" at Davenport (reported on the 3rd), 4.70" at Wilcox (reported on the 5th), and 4.20" four miles south-southeast of Roseland (reported on the 2nd). 

- Flooding: All flooding issues during the month occurred during the notably-wet first five days, and primarily within the following counties: southern Adams/Webster/Clay/Nuckolls/Fillmore/Thayer. Most of this flooding was relatively minor and more of a nuisance than anything, although some rural roads in the area sustained damage.
- Flash Flood Warnings: Officially, only one Flash Flood Warning was issued: on the evening of the 2nd for parts of Clay/Nuckolls/Fillmore/Thayer counties.
- Areal Flood Warnings/Advisories: Several were issued, with some of the more notable reports within them including: 1) minor flooding along the Little Blue River upstream of Hebron in Thayer County, and also along Big Sandy Creek...2) minor flooding along the Little Blue River in southeast Adams County, including at Crystal Lake.
- River Flood Warnings (gauge points): The only official/automated river gauge to flood was along the Little Blue River near Deweese, which actually slightly breached its minor flood stage of 10ft. TWICE in 48 hours, first from the evening of the 2nd to the evening of the 3rd, and then again during the afternoon and evening of the 4th. 

- Temperatures: September broke a two-month streak of slightly-cooler-than-normal months, as most official stations averaged 1-4º ABOVE normal, with the greatest above-normal departures focused across the western half of south central Nebraska. However, if not for a pronounced cool-down (highs mainly in the 50s) during the final three days, September would have finished even warmer versus average. In fact, the most notable "temperature event" of the month was a particularly hot 7-day stretch centered from the 14th-20th. At both Grand Island and Hastings, this was the hottest week so late in the year in 63+ years! During most of this week, high temperatures topped out between the mid-80s and mid-90s area-wide, with overnight lows falling no lower than the mid-60s. As for monthly extremes per official NWS observers/stations, some of the hottest readings focused between the 18th-20th, including: 97º at Cambridge and Webster Dam KS, 96º at Smith Center KS and Lexington airport, 95º at Hebron airport, Beaver City and Kirwin Dam KS. On the opposite end of the thermometer, the chilliest overnight lows occurred on the 26th, including: 33º at Ord airport, 34º at Greeley and Ravenna, and 35º at Cambridge and Beaver City. The 26th also featured the first frost of fall 2018 in some of these northern and western local counties. 

- Severe Thunderstorms/Tornadoes (for all finalized/official severe storm reports refer to NCEI Storm Events Database):
- # of confirmed tornadoes during September 2018: Zero (same as Sept. 2017)
- Largest known hail stone reported to NWS Hastings: 1.75" diameter/golf ball size...Red Cloud/Cowles area on the late afternoon of the 20th
- Strongest known measured thunderstorm wind gust: 78 MPH...Jewell KS (personal weather station) on the late afternoon of the 1st
- Notable thunderstorm damage reported to NWS Hastings (ground-truth reports): 
1) Very early morning of the 1st: severe winds of 60-70 MPH resulted in several reports of damage (mainly to trees) in the Grand Island/Doniphan/Central City areas.
2) Late afternoon of the 1st, damaging winds impacted parts of Jewell County KS, blowing the roof off an old radio communications building near Lovewell State Park
3) On the late afternoon of the 20th, a corridor of sporadic damaging winds tracked from Rooks County KS, northeastward into Webster/Nuckolls/Thayer counties in Nebraska. A few miles south of Stockton KS, power lines fell onto Highway 183, with two vehicles becoming entangled in them (no injuries). 
- # of Severe Thunderstorm Warnings issued by NWS Hastings: 22 (this was 14 more than Sept. 2017) 
- # of Tornado Warnings issued by NWS Hastings: 0 (same as Sept. 2017) 
- The most active severe weather days (generally with the most storms and/or most reports): 1st, 20th

2018 Nebraska Cooperative Observer Precipitation Tables (around 45 sites)
2018 Kansas Cooperative Observer Precipitation Tables (around 17 sites)

2017 Nebraska Cooperative Observer Precipitation Tables (around 45 sites)
2017 Kansas Cooperative Observer Precipitation Tables (around 17 sites)

Archived Precipitation Tables And Monthly Climate Stories