The most intense storm of the month, in fact many months, wrapped up across the central Plains on April 13, spreading a mix of wintry precipitation across the area, accompanied by numerous thunderstorms.  Not included in this episode was the spotty severe hail and wind which occurred in southeast South Dakota and southwest Minnesota prior to the onset of snowfall during the morning and afternoon of April 13.
Eventually, influx of colder air would change all precipitation over to snow,  and ushered in a record-breaking snowfall of 8 to 16 inches (some locations over 20 inches) and fierce winds gusting 50 to 60 mph to southeast South Dakota, southwest Minnesota, northwest Iowa and extreme northeast Nebraska. Snow drifts over 6 feet were reported in many locations.  Extremely low visibility persisted for almost a day for most locations, making travel very difficult if not impossible.
One person was killed in Rock County when the snowmobile he was riding collided with an interstate guard rail.

Blizzard in BON HOMME, SOUTH DAKOTA
From 13-APR-18 12:30:00 to 15-APR-18 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the evening hours of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting over 40 mph) whipped visibility to less than a quarter mile at times through the night and following day of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  A storm total snowfall of 6.6 inches was measured at Tyndall.

Blizzard in BEADLE, SOUTH DAKOTA
From 13-APR-18 09:30:00 to 14-APR-18 13:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Life threatening conditions developed during the late morning hours of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 56 mph at Huron) whipped visibility to less than a quarter mile at times through the day and into the morning hours of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  A storm total snowfall of 15.6 inches was amassed at Huron with 14.0 inches 2 miles southeast of Wessington.

Blizzard in GREGORY, SOUTH DAKOTA
From 13-APR-18 09:00:00 to 14-APR-18 19:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the afternoon of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 56 mph at Gregory) whipped visibility to less than a quarter mile at times into the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  Interstate 90 was closed from Chamberlain to Mitchell at 1330CST April 13 and remained closed until 0700CST April 15.  A storm total snowfall of 16.0 inches was measured at Gregory, 15.4 inches at Bonesteel and 14.1 inches 4 miles southwest of Burke.

Blizzard in LINCOLN, SOUTH DAKOTA
From 13-APR-18 21:15:00 to 15-APR-18 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the early morning of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 67 mph at Sioux Falls and 52 mph at Canton) whipped visibility to less than a quarter mile at times through the evening of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible. Interstate 29 was closed to Sioux Falls at 2000CST on April 13, and remained closed until 0800CST April 15. A storm total snowfall of 15.0 inches was measured 1 mile southeast of Tea.

Blizzard in MINNEHAHA, SOUTH DAKOTA
From 13-APR-18 21:15:00 to 15-APR-18 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Life threatening conditions developed during the early morning of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 67 mph at Sioux Falls) whipped visibility to less than a quarter mile at times through the evening of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible. Interstates 29 and 90 were closed from Sioux Falls west and north at 2000CST on April 13, and remained closed until 0800CST April 15. Poor visibility and heavy snow accumulation closed Joe Foss Field from 1730CST April 13 through 0700CST April 15.  Snow and ice accumulation along with the strong winds sheared the top 275 feet off an 875 foot radio tower knocking two local stations off the air for up to a couple weeks.  A storm total snowfall of 14.5 inches was measured at the NWS office in Sioux Falls with 13.2 inches near Hartford.

Blizzard in DOUGLAS, SOUTH DAKOTA
From 13-APR-18 13:00:00 to 15-APR-18 02:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting at times over 45 mph) whipped visibility to less than a quarter mile at times into the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  Interstate 90 was closed from Chamberlain to Mitchell at 1330CST April 13 and Mitchell to Sioux Falls from 2000CST April 13, and remained closed until 0700CST April 15.  A storm total snowfall of 12.6 inches was measured 10 miles west of Dimock.

Blizzard in SANBORN, SOUTH DAKOTA
From 13-APR-18 11:00:00 to 14-APR-18 23:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the late afternoon of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 60 mph at Mitchell and 56 mph at Huron) whipped visibility to less than a quarter mile at times through the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  A storm total snowfall of 18.0 inches was measured 3 miles northeast of Forestburg.

Blizzard in UNION, SOUTH DAKOTA
From 14-APR-18 02:00:00 to 14-APR-18 22:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Life threatening conditions developed during the early morning of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 45 mph at Elk Point) whipped visibility to less than a quarter mile at times through the evening of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible. A storm total snowfall of 4.0 inches was measured at 2 miles south southeast of Vermillion.

Blizzard in CLAY, SOUTH DAKOTA
From 14-APR-18 02:00:00 to 15-APR-18 00:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the early morning of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 45 mph at Vermillion) whipped visibility to less than a quarter mile at times into the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  A storm total snowfall of 4.0 inches was measured at Vermillion.

Blizzard in MOODY, SOUTH DAKOTA
From 13-APR-18 19:00:00 to 15-APR-18 09:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the late evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 55 mph at Flandreau) whipped visibility to less than a quarter mile at times through the afternoon of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  Interstate 29 was closed from the North Dakota border to Sioux Falls 2000CST April 13, and remained closed until 0800CST April 15.  A storm total snowfall of 10.5 inches was measured at Flandreau.

Blizzard in YANKTON, SOUTH DAKOTA
From 14-APR-18 00:45:00 to 14-APR-18 23:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the early morning of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 41 mph at Yankton) whipped visibility to less than a quarter mile at times through the evening of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible. A storm total snowfall of 8.0 inches was measured Yankton with 7.0 inches at 2 miles south southwest of Gayville.

Blizzard in BRULE, SOUTH DAKOTA
From 13-APR-18 10:00:00 to 14-APR-18 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the early afternoon of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 47 mph at Chamberlain) whipped visibility to less than a quarter mile at times into the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible. Interstate 90 was closed at 1330CST April 13 and did not reopen until 0700CST April 15.  A storm total snowfall of 14.0 inches was measured at Chamberlain and 7.0 inches 5 miles south of Chamberlain.

Blizzard in BROOKINGS, SOUTH DAKOTA
From 13-APR-18 12:00:00 to 15-APR-18 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the early morning hours of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 48 mph at Brookings and 46 mph at Volga) whipped visibility to less than a quarter mile at times into the afternoon of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible. Interstate 29 was closed from Brookings northward at 1500CST April 13, and from Brookings to Sioux Falls at 2000CST A storm total snowfall of 16.0 inches was measured at White and 12.5 inches near Brookings.

Blizzard in DAVISON, SOUTH DAKOTA
From 13-APR-18 12:00:00 to 15-APR-18 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 60 mph at Mitchell) whipped visibility to less than a quarter mile at times into the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  Interstate 90 was closed from Chamberlain to Mitchell at 1330CST April 13 and Mitchell to Sioux Falls from 2000CST April 13, and remained closed until 0700CST April 15.  A storm total snowfall of 16.2 inches was measured at Mitchell.

Blizzard in CHARLES MIX, SOUTH DAKOTA
From 13-APR-18 14:00:00 to 15-APR-18 02:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the afternoon of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 56 mph west of Geddes and 49 mph 1 mile northeast of Platte) whipped visibility to less than a quarter mile at times into the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  A storm total snowfall of 15.0 inches was measured at Wagner and 12.0 inches at Platte.

Blizzard in HANSON, SOUTH DAKOTA
From 13-APR-18 17:00:00 to 15-APR-18 05:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 60 mph at Mitchell) whipped visibility to less than a quarter mile at times through the morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  Interstate 90 was closed from Chamberlain to Mitchell at 1330CST April 13 and from Mitchell to Sioux Falls at 2000CST April 13, and remained closed until 0700CST April 15.  A storm total snowfall of 8.0 inches was measured at Alexandria.

Blizzard in HUTCHINSON, SOUTH DAKOTA
From 13-APR-18 23:00:00 to 15-APR-18 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 41 mph at Parkston) whipped visibility to less than a quarter mile at times through the afternoon of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.   A storm total snowfall of 9.0 inches was measured at Menno and 7.0 inches at Parkston.

Blizzard in KINGSBURY, SOUTH DAKOTA
From 13-APR-18 11:00:00 to 15-APR-18 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting over 45 mph at times) whipped visibility to less than a quarter mile at times through the early morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.   A storm total snowfall of 12.1 inches was amassed at DeSmet and 7.7 inches at Iroquois.

Blizzard in JERAULD, SOUTH DAKOTA
From 13-APR-18 09:00:00 to 14-APR-18 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the afternoon of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 66 mph at 8 miles south southwest of Wessington) whipped visibility to less than a quarter mile at times through the early morning of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.   A storm total snowfall of 14.0 inches was measured at Wessington Springs.

Blizzard in MCCOOK, SOUTH DAKOTA
From 13-APR-18 20:00:00 to 15-APR-18 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the early morning of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 67 mph at Sioux Falls) whipped visibility to less than a quarter mile at times through the evening of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible. Interstate 90 was closed from Mitchell to Sioux Falls at 2000CST on April 13, and remained closed until 0800CST April 15. A storm total snowfall of 12.0 inches was measured at Bridgewater and 10.0 inches at Montrose.

Blizzard in MINER, SOUTH DAKOTA
From 13-APR-18 15:00:00 to 15-APR-18 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the late evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 60 mph at Mitchell and 61 mph at Madison) whipped visibility to less than a quarter mile at times through the afternoon of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  A storm total snowfall of 11.0 inches was measured at Howard.

Blizzard in AURORA, SOUTH DAKOTA
From 13-APR-18 11:00:00 to 15-APR-18 02:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the late afternoon hours of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting over 50 mph at White Lake) whipped visibility to less than a quarter mile at times through the night and morning hours of April 14. State offices were closed and schools cancelled on April 13.  Interstate 90 was closed from Chamberlain to Mitchell at 1330CST April 13 and did not open again until 0700CST April 15.  White Lake reported a storm total snowfall of 10.0 inches.

Blizzard in LAKE, SOUTH DAKOTA
From 13-APR-18 15:30:00 to 15-APR-18 12:15:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the evening of April 13, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting up to 61 mph at Madison) whipped visibility to less than a quarter mile at times through the early afternoon of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.   A storm total snowfall of 14.0 inches was measured 2 miles southeast of Madison with 12.7 inches 2 miles north of Chester.

Blizzard in TURNER, SOUTH DAKOTA
From 14-APR-18 00:00:00 to 15-APR-18 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Life threatening conditions developed during the early morning of April 14, as the earlier mix of rain, sleet and snow changed to all snow, and brutal winds (gusting as high as 51 mph 1 mile southeast of Tea) whipped visibility to less than a quarter mile at times through the evening of April 14. State offices were closed and schools cancelled on April 13. Travel was not recommended for much of the two day period, if not impossible.  A storm total snowfall of 12.4 inches was measured at Marion.