Numerous thunderstorms developed over the area during the afternoon ahead of a surface cold front. Several of the storms became severe producing large hail, while one line segment resulted in one report of downed trees.
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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 IWX wrote it up.
Numerous thunderstorms developed over the area during the afternoon ahead of a surface cold front. Several of the storms became severe producing large hail, while one line segment resulted in one report of downed trees.
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 Northern Indiana wrote its last area forecast discussion before the first event at Apr 20, 12:46 PM EST, 27 minutes earlier.
Area Forecast Discussion National Weather Service Northern Indiana 146 PM EDT Thu Apr 20 2017 .SYNOPSIS... Issued at 140 pM EDT Thu Apr 20 2017 A cold front associated with low pressure moving through the upper Great Lakes will sweep east across our area this afternoon spawning scattered to numerous thunderstorms. An isolated storm may be severe this afternoon, mainly over northeast Indiana, northwest Ohio, and southeast Michigan. High pressure will build into the area Friday providing fair weather with cooler temperatures, which will then continue through the weekend. && .UPDATE... Issued at 1156 AM EDT Thu Apr 20 2017 Forecast generally on track. Combination of pre-frontal trough moving in from the west and additional subtle boundary bisecting the CWA SW to NE, as well as increasing instability should allow convection slowly expand and organize to some extent over the next several hours. Best shear presently on (and should generally remain with) warm front that has pretty much cleared the forecast area with area well rooted into warm sector. Surface based CAPE of 1000-1500 J/KG in place along/south of the warm front with slightly higher values along the cold front. HRRR still focusing development along pre-frontal features which seems right on track given trends over the past couple hours. Ramping up of pops into likely range still looks good given expected coverage. Could argue to go more of a sct to numerous wording but for now likely mention will suffice. KILX sounding at 12Z showed a decent EML that will settle in this afternoon and at least help pose a damaging wind threat with the cells that can gain enough updraft strength and some organization. && .SHORT TERM...(Today and Tonight) Issued at 300 AM EDT Thu Apr 20 2017 Potent sw trough over wrn MN this morning will continue ewd into the UP by evening as swwd trailing cold front accelerates ewd through the great lakes/OH valley as sfc low over central IA migrates newd into central MI. Ewd portion of sfc boundary currently stalled through cntrl IL/IN yet will mix rapidly nwd through daybreak corresponding to ramping low level warm advection. Still expect convection to fire twd 08Z timed with veering swrly H85 45kt jet and substantial pocket of theta-e working into nrn zones out of IL. Otherwise morning period expected to be quiet as low level theta-e min over ern MO lifts ne and LLJ weakens. Thereafter resurgence of LLj commences along/ahead of diffuse prefrontal sfc trough within rapidly destabilizing sfc based airmass. However erosion of eml along with poor deep layer shear suggest little if any organized severe risk this aftn. Nonetheless some marginal severe risk is implied with semi-organized multicell clusters within unidirectional swrly flow early to mid aftn. Strong post frontal drying and cold advection surge follows tonight with a lingering shra chc far southeast early this evening. && .LONG TERM...(Friday through Wednesday) Issued at 300 AM EDT Thu Apr 20 2017 Trailing sw coming onshore over nrn CA this morning will eject ewd through the mid MS valley this weekend as strong sfc ridging builds in across the lakes. Thus expect cool/dry weather will persist locally. In wake of this sys... energetic pacific wave train consisting of multiple disturbances will follow next week. Lead disturbance will minor out through the nrn lakes twd Tue followed by more vigorous sys developing through the ern corn belt late period. Building mid level ridging/low level thermal troughing expected ewd across the lakes/OH valley with substantial temp moderation back to well above normal by Tue and continuing into/through next weekend. && .AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon) Issued at 142 PM EDT Thu Apr 20 2017 Pre-frontal trough has spawned area of thunderstorms moving through KSBN currently and will reach KFWA by 19-20z. Not a lot of activity behind this line but expect some additional development as main cold front and mid level short wave approach. Not enough confidence to add another group of prevailing tsra at KSBN given lack of upstream activity so kept VCTS there while allowed a longer tempo to cover KFWA. Satellite and surface obs show extensive area of post frontal MVFR strato cu over IA and western IL. Hires guidance not handling this well but spectral models show a lot of low level moisture trapped under inversion tonight into Friday. Stayed MVFR through rest of tonight and Friday morning. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...Small Craft Advisory until 11 PM EDT Friday for LMZ043-046. && UPDATE...Fisher SYNOPSIS...T SHORT TERM...T LONG TERM...T AVIATION...Lashley Visit us at www.weather.gov/iwx Follow us on Facebook...Twitter...and YouTube at: www.facebook.com/NWSNorthernIndiana www.twitter.com/nwsiwx www.youtube.com/NWSNorthernIndiana
Hazardous Weather Outlook National Weather Service Northern Indiana 439 AM EDT Thu Apr 20 2017 INZ003>005-012>015-020-MIZ077>079-210900- La Porte-St. Joseph IN-Elkhart-Starke-Pulaski-Marshall-Fulton IN- White-Berrien-Cass MI-St. Joseph MI- 439 AM EDT Thu Apr 20 2017 /339 AM CDT Thu Apr 20 2017/ This hazardous weather outlook is for portions of southwest Michigan and northern Indiana. .DAY ONE...Today and Tonight Isolated to scattered thunderstorms are expected this afternoon. A strong storm with small hail and gusty winds is possible. .DAYS TWO THROUGH SEVEN...Friday through Wednesday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight. && Stay tuned to NOAA Weather Radio for further details or updates...or check our web site at weather.gov/iwx INZ006>009-016>018-022>027-032>034-MIZ080-081-OHZ001-002-004-005-015- 016-024-025-210900- Lagrange-Steuben-Noble-De Kalb-Kosciusko-Whitley-Allen IN-Cass IN- Miami-Wabash-Huntington-Wells-Adams-Grant-Blackford-Jay-Branch- Hillsdale-Williams-Fulton OH-Defiance-Henry-Paulding-Putnam-Van Wert- Allen OH- 439 AM EDT Thu Apr 20 2017 This hazardous weather outlook is for portions of northern Indiana... northwest Ohio and southwest Michigan. .DAY ONE...Today and Tonight Scattered to numerous thunderstorms are expected this afternoon. A few storms could reach severe limits with hail and potentially damaging winds especially along and east of Interstate 69. .DAYS TWO THROUGH SEVEN...Friday through Wednesday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is possible this afternoon. && Stay tuned to NOAA Weather Radio for further details or updates...or check our web site at weather.gov/iwx LMZ043-046-210900- New Buffalo MI to St Joseph MI-Michigan City IN to New Buffalo MI- 439 AM EDT Thu Apr 20 2017 This hazardous weather outlook is for portions of The Nearshore Waters of Southeastern Lake Michigan. .DAY ONE...Today and Tonight An isolated thunderstorm is possible from this morning into early afternoon. Hazardous conditions for small craft will develop today and continue through tonight. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Hazardous conditions for small craft are possible Friday. && Stay tuned to NOAA Weather Radio for further details or updates...or check our web site at weather.gov/iwx
The Northern Indiana radar (KIWX), 29 km away, was scanning. The volume nearest the first event began at 18:15 UTC.
1 thunderstorm wind, 1 hail. Local standard time, as filed.
Local media reported several downed tree branches in the area as well as a section of a wooden privacy fence.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Indiana in 2017Every state in 2017This day in weather historyWarnings in Indiana, April 2017
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: 695449, 695448.