Weak convection developing along a pre-existing boundary led to brief spin-up of a high-based funnel.
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The episode as NWS FSD wrote it up.
Weak convection developing along a pre-existing boundary led to brief spin-up of a high-based funnel.
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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Jun 26, 1:42 PM CST, 2 hours 25 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Sioux Falls SD 242 PM CDT Fri Jun 26 2020 .SHORT TERM...(This Evening through Saturday) Issued at 242 PM CDT Fri Jun 26 2020 The morning MCV continues to race east and suppress activity across the area. The better instability will remain south and east of the area which means we should see a quiet late afternoon and evening. While there are hints of some marginal surface based instability with little to no shear, convergence in the low levels is very weak. There is a little weak convergence along a boundary on the back edge of the instability that will sag south through the afternoon into early evening. This boundary is most noticeable on satellite as well as a small shift in winds from light northwest or calm to closer to due north. Not expecting severe weather but maybe an isolated funnel as the low level wind field is very weak, heating is good and the 0- 3km CAPE is about 100 J/kg. Other than this high pressure will settle in tonight with light winds expected. This will allow for a relatively cool start to Saturday morning. Lows likely in the upper 50s in a few spots with mostly 60 to 65 for early morning readings. South to southeast flow will gradually develop on Saturday but overall winds will remain light for everyone east of the James River. Environment is very dry so convection extremely unlikely anything would develop. Maybe some isolated activity in central Nebraska. Highs should be in the mid to upper 80s. .LONG TERM...(Saturday Night through Friday) Issued at 242 PM CDT Fri Jun 26 2020 Saturday night into Sunday morning weak upper level troughing will spread onto the Western High Plains. This will bring a bit of an increase in the low level jet, but for now moisture and instability are not very impressive. The focus could remain mostly in Nebraska Saturday night but will maintain a low chance near the Missouri River. This threat will continue into Sunday morning with the better chances east of I-29. Elevated instability and shear just a touch better but still not anticipating anything more than an isolated severe threat. And there is still a chance that nothing will develop if low to mid level moisture does not accompany the increasing winds and convergence. Saturday night lows and Sunday highs warmer. Lows mostly mid to upper 60s with highs upper 80s to lower 90s. Sunday afternoon into the evening for now not looking like we will get a whole lot. Highway 14 and eastern parts of northwest IA and southwest MN may see a continued threat into the afternoon as a weak mid level wave moves through. However, the remainder of the area looks very capped. This trend will likely continue into Monday with very warm conditions and a decent amount of instability, but capping will likely suppress thunderstorm development. Especially with some upper level ridging building as well. Highs both Sunday and Monday should be roughly 87 to 94 with morning lows around 70. Tuesday into Thursday the trough begins to lift northeast and an upper level jet max is expected to spread onto the Western High Plains. If the timing of this wave remains close to what is in the models Tuesday night into Thursday night should see the better chances for thunderstorms. There will likely be a severe threat and heavy rain threat at some point in time during this window. Highs Wednesday into Friday likely to not be as hot and mainly in the 80s. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1219 PM CDT Fri Jun 26 2020 Scattered diurnally driven cumulus clouds based about 3000-5000 kft are expected this afternoon. An isolated sprinkle will be possible as well. Still a very small chance for a thunderstorms near KSUX and KSLB but confidence too low to include in TAF. Otherwise VFR through the period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && SHORT TERM...08 LONG TERM...08 AVIATION...08
Hazardous Weather Outlook National Weather Service Sioux Falls SD 432 AM CDT Fri Jun 26 2020 IAZ001>003-012>014-020-021-031-MNZ071-072-080-081-089-090-097-098- NEZ013-014-SDZ038>040-050-052>071-270945- Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-Woodbury- Lincoln-Murray-Cottonwood-Nobles-Jackson-Pipestone-Rock-Dixon-Dakota- Beadle-Kingsbury-Brookings-Gregory-Jerauld-Sanborn-Miner-Lake-Moody- Brule-Aurora-Davison-Hanson-McCook-Minnehaha-Charles Mix-Douglas- Hutchinson-Turner-Bon Homme-Yankton-Union- 432 AM CDT Fri Jun 26 2020 This Hazardous Weather Outlook is for northwest Iowa, west central Iowa, southwest Minnesota, northeast Nebraska, central South Dakota, east central South Dakota, south central South Dakota and southeast South Dakota. .DAY ONE...Today and tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. Increased humidity will return to the region early next week. This along with warming temperatures could push afternoon heat indices into the 90s in some areas Sunday through Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. IAZ022-032-270945- Buena Vista-Ida- 432 AM CDT Fri Jun 26 2020 This Hazardous Weather Outlook is for northwest Iowa and west central Iowa. .DAY ONE...Today and tonight. There is a small chance of thunderstorm redevelopment during the early to mid afternoon. If storms do develop, the strongest storms may be capable of producing gusty winds, or hail to the size of quarters. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. Increased humidity will return to the region early next week. This along with warming temperatures could push afternoon heat indices into the 90s in some areas Sunday through Tuesday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1107 AM CDT FRI JUN 26 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0418 AM TSTM WND GST 2 WNW BERGEN 43.80N 95.03W
06/26/2020 E50 MPH JACKSON MN EMERGENCY MNGR
&&
MDPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1152 AM CDT FRI JUN 26 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0821 PM HAIL 3 SE SIOUX FALLS 43.51N 96.70W
06/25/2020 U0.75 INCH MINNEHAHA SD PUBLIC
REPORT FROM MPING: DIME (0.75 IN.).
0807 PM HAIL 5 W SIOUX FALLS 43.53N 96.84W
06/25/2020 U0.50 INCH MINNEHAHA SD PUBLIC
REPORT FROM MPING: HALF-INCH (0.50 IN.).
0802 PM HAIL 5 W SIOUX FALLS 43.53N 96.84W
06/25/2020 U0.75 INCH MINNEHAHA SD PUBLIC
REPORT FROM MPING: DIME (0.75 IN.).
0644 PM TSTM WND GST 3 SE MONTROSE 43.67N 97.15W
06/25/2020 M69 MPH MCCOOK SD PUBLIC
MEASURED ON THE INSTRUMENT MONTROSE SD547.
0738 AM HEAVY RAIN MADISON 44.01N 97.11W
06/26/2020 M2.23 INCH LAKE SD PUBLIC
24 HOUR PRECIPITATION TOTAL.
0726 AM HEAVY RAIN 5 SW DE SMET 44.34N 97.62W
06/26/2020 M6.30 INCH KINGSBURY SD PUBLIC
0650 AM HEAVY RAIN DE SMET 44.38N 97.55W
06/26/2020 M1.86 INCH KINGSBURY SD CO-OP OBSERVER
0400 AM FLASH FLOOD 8 S DE SMET 44.27N 97.55W
06/26/2020 KINGSBURY SD LAW ENFORCEMENT
RAPIDLY FLOWING WATER TO A FOOT DEPTH OVER
HIGHWAY 25 AT 215TH ST.
1201 AM FLASH FLOOD 6 S IROQUOIS 44.28N 97.85W
06/26/2020 KINGSBURY SD LAW ENFORCEMENT
LOCAL LAW ENFORCEMENT CAME ACROSS DEEP WATER
FLOWING ACROSS THE ROAD. DID NOT KNOW
EXACTLY HOW DEEP, BUT DEEP ENOUGH THAT HE
FELT HE SHOULD TURN AROUND.
0555 PM TSTM WND GST 4 ENE ALEXANDRIA 43.67N 97.71W
06/25/2020 M66 MPH HANSON SD MESONET
MESONET STATION 213 SD RWIS ALEXANDRIA.
0549 PM TSTM WND GST 3 N MITCHELL 43.77N 98.04W
06/25/2020 M59 MPH DAVISON SD ASOS
0535 PM TSTM WND GST 3 N MITCHELL 43.77N 98.04W
06/25/2020 M66 MPH DAVISON SD ASOS
0438 PM HAIL 14 WNW PLATTE 43.49N 99.07W
06/25/2020 E1.00 INCH CHARLES MIX SD PUBLIC
TRAINED SPOTTER RECEIVED REPORT FROM HIS
PARENTS.
0433 PM TSTM WND GST 17 WNW PLATTE 43.49N 99.15W
06/25/2020 E60 MPH CHARLES MIX SD TRAINED SPOTTER
SPOTTER RECEIVED HEAVY RAINFALL, AND STRONG
WINDS ESTIMATING UP TO 60 MPH.
0352 PM HAIL 15 WNW PLATTE 43.47N 99.13W
06/25/2020 E0.70 INCH CHARLES MIX SD PUBLIC
0431 PM HAIL 6 N KIMBALL 43.83N 98.98W
06/25/2020 E1.00 INCH BRULE SD PUBLIC
HEAVY RAINFALL, HAIL TO THE SIZE OF
QUARTERS, WITH WINDS GUSTING TO 30 MPH.
0422 PM HAIL 18 S PUKWANA 43.52N 99.17W
06/25/2020 E1.00 INCH BRULE SD TRAINED SPOTTER
DELAYED REPORT. SENT PIC OF QUARTER TO
NICKEL SIZED HAIL VIA SOCIAL MEDIA.
0600 AM HEAVY RAIN 6 SSW IROQUOIS 44.29N 97.92W
06/26/2020 M3.48 INCH BEADLE SD PUBLIC
0600 AM HEAVY RAIN 6 SSE CAVOUR 44.29N 98.01W
06/26/2020 M3.48 INCH BEADLE SD PUBLIC
0449 PM HAIL 11 N WHITE LAKE 43.89N 98.70W
06/25/2020 M1.00 INCH AURORA SD TRAINED SPOTTER
JUST A COUPLE HAIL STONES.
0418 AM TSTM WND GST 2 WNW BERGEN 43.80N 95.03W
06/26/2020 E50 MPH JACKSON MN EMERGENCY MNGR
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
119 PM CDT FRI JUN 26 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0830 AM FLASH FLOOD 7 W CARTHAGE 44.15N 97.85W
06/26/2020 SANBORN SD PUBLIC
WATER FLOWING OVER ROADWAY.
&&
BTThe Sioux Falls radar (KFSD), 15 km away, was scanning. The volume nearest the first event began at 22:07 UTC.
1 funnel cloud. Local standard time, as filed.
Multiple reports were received from spotters and law enforcement of non-thunderstorm funnel clouds.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2020Every state in 2020This day in weather historyWarnings in South Dakota, June 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: 907153.