Does not compute! That must be what residents of Iowa and the Midwest have have been saying to themselves on Tuesday as a ferocious heat wave unprecedented in intensity for so early in the year sent temperatures soaring as high as 108. Just two weeks ago, the deepest snowfall ever measured during any May of record buried a wide swath from Arkansas to Minnesota, with Iowa breaking its all-time snowfall record for May (13 accumulation at Osage on May 1 - 3.) And how's this for a definition of "Weather Whiplash": Sioux City, Iowa had their first-ever snowfall on record in the month of May on May 1 (1.4"), but hit an astonishing 106 yesterday. Not only was this their hottest temperature ever measured in the month of May, but only two June days in recorded history have been hotter (June, 10, 1933: 107 and June 21, 1988: 108.) On May 12th they registered 29, and thus had a 77 rise over 56 hours (from 6 a.m. May 12 to 1:30 p.m May 14.)The hottest temperature of all on Tuesday was 108 at Tekamah, Nebraska. This is just 2 short of warmest temperature ever recorded in the state of Nebraska during May: 110 at Broken Bow in 1895 (exact day unknown.) Numerous all-time early season heat records were set on Tuesday, making the event the most notable May wave in the Midwest since a multi-day event in 1934. That heat wave was not preceded by unusually cold weather, which is what makes the May 2013 Midwest heat event truly extraordinary. A few notable cases of "Weather Whiplash" from the May 14, 2013 heat wave:

- Chicago, Illinois hit 91, after hitting a low of 36 the previous morning. The 1-day temperature swing of 52 was the city's greatest on record for the month of May.

- Rochester, Minnesota, where 14.5 of snow fell just 10 - 12 days ago (4th greatest snowstorm for any month on record), saw an all-time early season heat record of 97 on May 14th. The previous day, May 13th, it was 32 in Rochester--a 65 rise in temperature over the course of 36 hours.

- Omaha, Nebraska hit 101, the earliest 100 on record (old record 102 on May 29, 1934). It was 32 in Omaha on May 12th! That tied for the coldest so late in the season with 32 on 5/13/1997 and also on 5/15/1983.

- Albert Lea and St. James, Minnesota hit 102 (hottest in the state on Tuesday.) Both cities had May snow less than two weeks previously. Tuesday morning, it was 27 at Crane Lake and Silver Bay, for a same-day state temperature spread of 75 in Minnesota. This is a relatively common figure for California or Texas, but almost unprecedented for a Midwestern state.

- Minneapolis hit 98, the hottest so early in season (next is 99 on May 22, 1925). May record is 106 on May 31, 1934 (the only time 100 has been measured during May).

- Norfolk, Nebraska hit 103, the hottest temperature ever measured so early in the year (previous record: 103 on May 25, 1967. A daily record low of 29 was recorded on May 12th, just two days previous.