Mainly within an hour either side of midnight CDT on the night of Sunday the 9th into Monday the 10th, a fairly pronounced heat burst (perhaps a series of them) affected Rooks County, prompting both measured/estimated wind gusts up to around 70 MPH. On the south side of Stockton, a mesonet recorded a peak gust of 61 MPH, and there were reports of some minor tree damage in town.
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The episode as NWS GID wrote it up.
Mainly within an hour either side of midnight CDT on the night of Sunday the 9th into Monday the 10th, a fairly pronounced heat burst (perhaps a series of them) affected Rooks County, prompting both measured/estimated wind gusts up to around 70 MPH. On the south side of Stockton, a mesonet recorded a peak gust of 61 MPH, and there were reports of some minor tree damage in town. Another mesonet station between Palco and Zurich displayed tell-tale signs of a heat burst in its temperature/dewpoint data, as the observation around 9 p.m. CDT was 86/67 F, but closer to midnight had warmed/dried notably to 94/48 F, before gradually stabilizing (cooling/moistening) through the pre-dawn hours. The most telling personal evidence of heat burst activity came from Rooks County State Park, where a man relayed an account of being caught off guard by a low roaring sound followed by several minutes of strong winds he estimated to be at least 70 MPH, which damaged some trees. He noted how unusual the situation was given the lack of obvious thunderstorm activity in the immediate area. From a meteorological standpoint, this was a fairly classic setup for nocturnal heat burst activity. For one, radar data confirmed that Rooks County was underneath high-based, light precipitation, generally 20-60 miles north of a small cluster of thunderstorms drifting east-southeast outside the local area. Mesoscale analysis also confirmed very warm mid level temperatures were present (around 14 C at 700 millibars), along with steep mid level lapse rates. The preceding afternoon of the 9th was quite hot across north central Kansas, with high temperatures well into the mid-upper 90s.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Hastings, NE wrote its last area forecast discussion before the first event at Aug 9, 11:03 PM CST, 4 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Hastings NE 1203 AM CDT Mon Aug 10 2020 ...Aviation Update... .SHORT TERM...(This evening through Monday Night) Issued at 413 PM CDT Sun Aug 9 2020 Hot and humid conditions continue across the forecast area under sunny to mostly sunny skies and generally lgt S wind. Convection has recently fired along CO/KS border in environment characterized by deep mixing/steep low level lapse rates amidst weak convergence. Water vapor shows a strong upper level low pressure system over central Canada with trough axis extending into the Intermountain West and upper riding over the Deep South. This results in zonal to slight SWrly flow aloft, locally. A couple very weak shortwaves appear to be within this flow over the central High Plains. This Evening-Overnight: Main concern is potential for convection. Latest SPC mesoscale analysis places moderate to strong instability (MLCAPE 2-3K J/kg for most of CWA) amidst moist BL and very steep mid-level lapse rates of 8-9 C/km. Effective shear is rather weak at only 15-25kt. Also, the sfc based instability is capped off due to very warm mid level temps, w/ H7 temps 14-16C. Activity currently developing along CO/KS border may try to unzip NE to our far W counties 23Z-01Z along weak convergent zone, but with only weak/nebulous sfc trigger, this remains uncertain. Water vapor imagery also shows fairly dry mid to upper levels, which will further discourage deep convection. IF convection can breach the cap, strong to severe storms would be poss given magnitude of CAPE and presence of very steep low to mid level lapse rates. Hail would probably be limited to initial cells, before weak shear, dry mid levels, and high delta theta-e values lead to outflow dominated cells and primarily a wind threat as activity shifts E/NE. Unless convection becomes organized or develops substantial cold pool, its unlikely a developing LLJ (25-30kt) would be enough to sustain convection past midnight given aforementioned warm mid level temps, but this will depend on organization. So, overall, a conditional threat for severe exists over roughly NW 2/3rds of CWA between 6pm and midnight, but latest hi-res models are mixed, thus only a Marginal risk for svr from SPC. Realistically, threat is probably even limited to areas N/W of Tri Cities. Additional elevated convection will likely fire well to the N along elevated convergence associated w/ H85-H7 front, and cooler mid level temps. Most models carry this activity to the E/SE and keeps it N/NE of the CWA, but its close enough to carry a 20-30 POP. Also, can't completely rule out some "sunrise surprise" over E CWA as LLJ veers after midnight, but again, chcs are limited due to the cap. A sfc cold front will enter far N CWA around 06Z, then sink S to around I-80 by 12Z, though this will depend on convection. Monday: Main issue is cloud cover behind the front and the effect on high temps. Front will slowly but steadily sink S thru the AM, then potentially stall out somewhere near or just N of I-70 corridor, very near far SE corner of CWA. Behind the front, models show refreshingly breezy N to NE winds for AM-early aftn, perhaps gusting even as high as 30-35mph, depending on the model. Where they disagree is the amount of stratus just beneath sharp frontal inversion. NAM is by far the most aggressive w/ clds, and thus much cooler, but appears to be an outlier. Don't disagree there may be low clds along and immediately behind front, but HREF, GFS and EC all suggest these clds mix out by late AM, with extended versions of HRRR/HRRRX/RAP not too dissimilar. Thus, have discounted the much colder NAM solution (60s-70s!), and went w/ more of a consensus from the other models for high temps. This results in upper 70s to low 80s NE zones, and mid to upper 80s KS zones, though 90s are certainly poss depending where front stalls and cld cover. Not a straightforward temp forecast, for sure. 20-30 PoPs continue in Mon aftn for SE half of CWA, but latest thinking is most areas stay dry. Best chcs will be KS zones toward HJH. Mitchell Co is clipped by latest Day 2 SPC outlook, but not advertising attm given main focus looks to be just S/SE. Monday Night: Front should sink far enough S and gradually wash out, leaving us PoP free. Expect fairly comfortable lows in the upper 50s N, to low to mid 60s elsewhere. .LONG TERM...(Monday night through Sunday) Issued at 413 PM CDT Sun Aug 9 2020 Fairly typical summer pattern expected in the extended. Models show troughing over SE Canada and ridging over the Desert SW, which would leave the CWA in zonal flow. Weak perturbations within zonal flow justifies the smattering of 20-30 PoPs Tue into Fri. Tough to get a handle on any particular time period for better chances, but if any, perhaps Wed-Wed night-Thu would be a candidate. Just too difficult to really add any value to the extended forecast at this time in terms of precipitation specifics other to say that the forecast probably looks more active than it will be in reality, but PoPs are 40 or less. After the cool down Mon that bleeds into Tue, the rest of the week looks fairly seasonable with daily highs in the 80s to 90s, and lows in 60s to low 70s. && .AVIATION...(For the 06Z KGRI/KEAR TAFS through 06Z Tuesday) Issued at 1159 PM CDT Sun Aug 9 2020 Cold frontal boundary is advancing south thru Nebraska tonight and will bring a wind shift to the north/northeast with winds increasing behind the front during the morning Monday. Convection thus far has remained far enough away from the terminals (well north and south) so haven't mentioned any convection for KGRI or KEAR attm. Models suggest the potential for some lower clouds behind the front but not seeing much development just yet, but will monitor and have included some scattered MVFR clouds with better potential for lower cigs beyond this TAF period. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && SHORT TERM...Thies LONG TERM...Thies AVIATION...Fay
Hazardous Weather Outlook National Weather Service Hastings NE 807 PM CDT Sun Aug 9 2020 KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087- 110115- Phillips-Smith-Jewell-Rooks-Osborne-Mitchell-Valley-Greeley-Nance- Sherman-Howard-Merrick-Polk-Dawson-Buffalo-Hall-Hamilton-York- Gosper-Phelps-Kearney-Adams-Clay-Fillmore-Furnas-Harlan-Franklin- Webster-Nuckolls-Thayer- 807 PM CDT Sun Aug 9 2020 This Hazardous Weather Outlook is for south central Nebraska and portions of north central Kansas. .DAY ONE...Tonight. A few strong to severe thunderstorms are possible this evening and through the overnight hours, mainly for areas along and northwest of a line extending from Stockton, Kansas to Clay Center and York, Nebraska. The primary hazards from the storms will be damaging winds of 60 mph or greater and large hail up to the size of quarters. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Intermittent chances for thunderstorms exist across portions of the outlook area from Monday through Friday evening. Continue to monitor the latest forecasts for updates on storm chances and severe weather potential. .SPOTTER INFORMATION STATEMENT... Spotters activation may be needed this evening for locations along and north of a line from Stockton, Kansas to York, Nebraska. && More information may be obtained at the following web page: https://www.weather.gov/hastings Rossi
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Heat burst wind gusts estimated to be as high as 70 MPH resulted in mainly some tree damage in and around the Stockton area, including at Rooks County State Park.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Kansas in 2020Every state in 2020This day in weather historyWarnings in Kansas, August 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 917325.