Groups of thunderstorms slowly moved across the Sandhills during the evening hours, producing flooding in Boyd County and severe wind gusts in Custer County.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LBF wrote it up.
Groups of thunderstorms slowly moved across the Sandhills during the evening hours, producing flooding in Boyd County and severe wind gusts in Custer County.
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 North Platte, NE wrote its last area forecast discussion before the first event at Jul 29, 5:32 PM CST, 2 hours 3 minutes earlier.
Area Forecast Discussion National Weather Service North Platte NE 632 PM CDT Wed Jul 29 2020 .SHORT TERM...(This evening through Thursday night) Issued at 307 PM CDT Wed Jul 29 2020 Near-term concerns revolve around the threat for strong to briefly severe thunderstorms later this afternoon and recurring chances at rain and thunderstorms which may lead to locally heavy rainfall through Thursday. The period begins with the local area caught between a strengthening southwest ridge and a departing cut-off trough across southeast Canada. Within the slightly zonal to northwest flow aloft locally, a pronounced shortwave trough currently situated across the central to northern high plains is slowly drifting southeast tonight through Thursday. Multiple embedded vort-maxes caught within this feature will move over a warm and humid airmass. Finding the best overlap of shear and instability is somewhat difficult as instability increases as you get further northeast, likely due to better moisture quality. Meanwhile, the stronger shear is further southwest closer to the main h5 speedmax overtop southeasterly surface winds. Though instability isn't overly strong across the southwest, lapse rates are more favorable and given their collocation with the stronger shear, lends highest confidence in this being the location for best chances at a strong to severe thunderstorm. As vorticity advection increases in concert with stronger mid-level frontogenesis, will see an increase in thunderstorm activity for areas west of Highway 83 over the next few hours. Ongoing activity to the east is likely being driven by strong vorticity advection overtop strong, uncapped instability. Again, shear is weaker the further east you get so the threat for strong to severe storms is lower here. Outside of the strong to severe thunderstorm threat, heavy rainfall is likely with most thunderstorm activity through the overnight hours. PWATs are currently around 1.1-1.3" and anticipated to increase slightly (to around 1.4-1.5") as h85 flow continues to advect moisture into the area. Storm motion will be slow, likely less than 20 knots this afternoon and early this evening with efficient rain processes leading to moderate to heavy downpours. Great corridor of concern is generally along a Merriman through Sutherland corridor where 0.5-1.0" is likely and localized amounts approaching 2-3" cannot be ruled out. Will need to monitor for hydro concerns but given FFG across much of this area at ~2.5"/4.0" for the 1 hour/3 hour guidance respectively, thinking flash flooding threat is limited enough to preclude a watch. Any notably heavy rain amounts are expected to remain fairly localized. As the vort max continues to move overhead overnight, forcing for ascent will decrease but will be maintained enough to allow a continuation of rain and thunderstorms during the overnight hours and early Thursday. Coverage of thunderstorm activity will begin to diminish Thursday afternoon as subsidence behind the departing trough exits to the southeast. Cloud cover will gradually decrease from the northwest to southeast during the late day. Temperatures will remain cool with highs in the upper 70s to low 80s, or about 10 to 15 degrees below normal for late July. With decreasing clouds Thursday night, lows will fall back into the mid 50s west to near 60 in the far northeast. .LONG TERM...(Friday through Wednesday) Issued at 307 PM CDT Wed Jul 29 2020 Beginning 12z Friday. Period will begin with highly amplified northerly flow behind the departing trough that will be pushing into the lower Mississippi River valley by this time. Various weak perturbations will be pushing through the mid-level flow but given fairly dry air in place with PWATs at less than an inch, thinking any rain/thunderstorm chances will be fairly limited. Add into that a fairly stout capping inversion, thinking most locations will remain dry. Temperature trend over the past few days for the upcoming weekend has been to decrease daytime highs as downstream trough stalls across the southeast CONUS. While high temperatures on Friday and Saturday may approach normal values, another shot of cooler Canadian air will move in following the passage of a weak surface boundary. Some light PoPs are possible along this boundary, with favored areas generally being east of Highway 83 where some mid- level cool air may aid modest mid-level lapse rates and thus some weak convection during the afternoon and evening hours. T temperatures at h85 will decrease a good 5 degrees from Saturday to Sunday while remaining fairly consistent for Sunday into Monday suggesting daytime highs likely holding onto the 70s for most with some locations, particularly areas west of Highway 61, perhaps climbing into the lower 80s each day. Moist upslope flow combined with a weak shortwave could help spark off some showers and thunderstorms Sunday afternoon and evening across mainly southwest Nebraska, but placement of best moisture plume varies between the ECMWF and GFS by 75 to 100 miles. The GFS advertises dry weather for our area but the ECWMF is more bullish. Will leave PoPs in there but limit to Slight Chance given lingering uncertainty. Thinking Monday will be a dry day as subsidence behind departing trough will effectively clear us out with partly to mostly sunny skies expected as dry air fills in across the area thanks to a Canadian high pressure system nosing in from the northeast. Appreciable precipitation chances return on Tuesday as both the GFS and ECMWF advertise a fairly strong shortwave trough rounding the southwestern ridge moving overhead. Southerly low-level flow developing ahead of the this feature will help push higher moisture quality back into the area. While too early to get into specifics, given quality of moisture (dew points in the low 60s), instability aloft (SBLI values falling to -4 to -8 range), and proximity to mid- level speed max at h5, threat for strong to severe convection cannot to ruled out at this time but should be considered low confidence at this time. The long range pattern looks favorable for multiple waves of rain and thunderstorms as upper level pattern suggests multiple disturbances rounding the ridge right through the central high plains. Precisely timing any individual wave this far in advance is difficult at best so will leave PoPs broad brushed for now. As ridging remains anchored across the southern Rockies for Tuesday and beyond, temperatures will gradually trend warmer day-by-day with a return to nearly all 80s by Wednesday and approach the upper 80s to low 90s once again by the end of the week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 629 PM CDT Wed Jul 29 2020 Scattered thunderstorms will continue through the rest of the evening and overnight, impacting both KVTN and KLBF terminals. MVFR to IFR conditions will be possible with the heaviest thunderstorms, along with brief wind gust. Thunderstorms and rainfall will begin to taper off by late Thursday afternoon and evening. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && SHORT TERM...Jurgensen LONG TERM...Jurgensen AVIATION...Gomez
Hazardous Weather Outlook National Weather Service North Platte NE 324 PM CDT Wed Jul 29 2020 NEZ004>010-022>029-035>038-056>059-069>071-094-302030- Sheridan-Eastern Cherry-Keya Paha-Boyd-Brown-Rock-Holt-Garden- Grant-Hooker-Thomas-Blaine-Loup-Garfield-Wheeler-Arthur-McPherson- Logan-Custer-Deuel-Keith-Perkins-Lincoln-Chase-Hayes-Frontier- Western Cherry- 324 PM CDT Wed Jul 29 2020 /224 PM MDT Wed Jul 29 2020/ This Hazardous Weather Outlook is for portions of western and north central Nebraska. .DAY ONE...TONIGHT. A slow moving storm system will cause showers and thunderstorms to develop this afternoon into tonight. Locally heavy rainfall could lead to some flooding. In addition, a couple of thunderstorms may be strong or briefly severe through this evening, mainly south of a line from Chappell to Brady. Strong gusty winds and large hail will be the main threats. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. Showers and thunderstorms will continue Thursday into Thursday evening. There will continue to be the potential for some locally heavy rainfall through this time. Isolated thunderstorm chances continue Friday through Tuesday. Severe threat is uncertain at this time. .SPOTTER INFORMATION STATEMENT... Spotter are encouraged to report any significant weather, including heavy rain reports. && Get your weather, hydrological, and climate information at http://www.weather.gov/northplatte
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
751 PM CDT WED JUL 29 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0745 PM HEAVY RAIN BASSETT 42.58N 99.54W
07/29/2020 M1.55 INCH ROCK NE PUBLIC
REPORTED 1.55 INCHES OF RAINFALL IN 90 MINUTES.
&&
CBROWNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
752 PM CDT WED JUL 29 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0736 PM HEAVY RAIN SENECA 42.04N 100.83W
07/29/2020 E2.43 INCH THOMAS NE PUBLIC
STORM TOTAL OF 2.43 INCHES VIA SOCIAL MEDIA.
&&
JGOMEZPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
755 PM CDT WED JUL 29 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0743 PM HEAVY RAIN GORDON 42.81N 102.20W
07/29/2020 M2.50 INCH SHERIDAN NE PUBLIC
STORM TOTAL RAINFALL.
&&
CBROWNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
800 PM CDT WED JUL 29 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0751 PM HEAVY RAIN 16 SW MULLEN 41.88N 101.26W
07/29/2020 E1.10 INCH HOOKER NE PUBLIC
RAINFALL OF 1.10 INCHES IN 30 MINUTES AND STILL RAINING.
REPORT VIA SOCIAL MEDIA.
&&
JGOMEZSpecial Weather Statement National Weather Service North Platte NE 800 PM CDT Wed Jul 29 2020 NEZ036-037-059-300145- McPherson NE-Lincoln NE-Logan NE- 800 PM CDT Wed Jul 29 2020 ...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL LINCOLN... SOUTHWESTERN LOGAN AND SOUTHEASTERN MCPHERSON COUNTIES UNTIL 845 PM CDT... At 800 PM CDT, Doppler radar was tracking strong thunderstorms along a line extending from near Ringgold to 8 miles west of Tryon. Movement was southeast at 20 mph. Dime size hail and wind gusts up to 50 mph will be possible with these storms. Locations impacted include... Ringgold. This includes the following highways... Highway 92 between mile markers 206 and 224. Highway 97 between mile markers 11 and 26. Highway 83 between mile markers 99 and 105. PRECAUTIONARY/PREPAREDNESS ACTIONS... Torrential rainfall is also occurring with these storms, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for southwestern Nebraska. LAT...LON 4132 10049 4131 10112 4153 10122 4155 10063 TIME...MOT...LOC 0100Z 305DEG 15KT 4151 10085 4151 10110 CDC
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
801 PM CDT WED JUL 29 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0155 PM HEAVY RAIN 22 N MULLEN 42.36N 101.04W
07/29/2020 M1.05 INCH CHERRY NE PUBLIC
REPORTED 1.05 INCHES IN 30 MINUTES.
&&
CBROWNThe North Platte radar (KLNX), 177 km away, was scanning. The volume nearest the first event began at 01:34 UTC.
1 flash flood, 1 thunderstorm wind. Local standard time, as filed.
A cooperative observer reported street flooding throughout Butte.
A cooperative observer measured a 58 mph wind gust with a personal weather station southwest of Callaway.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2020Every state in 2020This day in weather historyWarnings in Nebraska, July 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: 904674, 904673.