5/8/17

Tornadoes, Snowstorms and Heat Waves - Oh May!


While March is generally considered one of the most volatile months in Southeast Lower Michigan weather-wise, May doesn't pull any punches either! You would think that by May; spring's extreme weather in these parts would settle down some - don't bet on it. Scanning over a century's worth of weather records show some interesting and quite variable weather conditions during the upcoming month.

Tornadoes! 


One of the strongest and earliest documented tornadoes in Southeast Lower Michigan occurred in May, 1896! While details are sketchy, evidently a massive tornado plowed across Oakland and Lapeer Counties during the early evening hours on May 25th sometime between 7 PM to 9 PM. The tornado leveled numerous homes in the towns of Ortonville, Oakwood and Thomas ( both no longer exist). In fact, parts of these homes were found 12 miles away! At least 47 people were killed, including nine people from one house alone, along with approximately 100 injured as a result of this vicious storm which has been estimated as an EF-5 (wind speeds greater than 200 mph). Later that evening (likely closer to 9 PM), another tornado was seen in Sanilac County which possibly was from the same parent of super-cell thunderstorms. It's also interesting to note that May of 1896 turned out to be the fourth warmest May (see May Top 20 records chart at the end of this write-up) in recorded history at Detroit, perhaps the unseasonably warm weather helped fuel the severe weather. I was interviewed by the Oakland Press years back in 2009 about this terrible tornado. Also, included in the article are pictures of the now defunct town Oakwood before and after.


Some of the strongest tornadoes to hit Southeast Lower Michigan occurred in the early to mid 1950's. The most noteworthy was the monster Flint/Beecher tornado that occurred in 1953 also an EF-5, but that storm hit in the month of June (8th). (An in‑depth article I wrote on the tornado can be found here). Unfortunately, Genesee County was hit again just three years later on May 12th, 1956 with another devastating tornado (EF4 on the enhanced fujita scale with a wind of 166‑200 mph). After the Flint/Beecher storm, this is the second strongest tornado to hit Genesse County. Like its predecessor, this storm also formed in the Flint vicinity (3 miles east of Flint) but then tracked southeast to 3 miles northwest of Atlas rather than east. This tornado killed 3 people and injured 116 while taking out more than 100 homes and five commercial buildings along its path. The average width of the storm was about 300 feet and it is the last killer tornado to hit Genesse County.

Just less than a month before the massive Flint/Beecher tornado in June 8th, on May 21st,1953 the first of two EF4's (166-200 mph) tornadoes ever to hit St. Clair county tore a mean path through the south side of Port Huron. By all accounts, the south side of Port Huron was devastated by this twister. There were two deaths and 68 injuries along with an estimated 90 homes destroyed and another 300 damaged as the tornado ripped through the region. Also, along with the loss of homes, an additional 83 buildings were destroyed and another 124 buildings damaged. As a severe thunderstorm moved northeast across St. Clair county, the tornado was spawned just southwest of Port Huron over the town of Smith's Creek. The tornado then took aim on the south side of Port Huron, reaching nearly a mile wide across at its worst as it tore through the area on its way into Canada.


The second EF4 tornado to hit St. Clair county also occurred in May...May 8th, 1964 The tornado actually developed over Macomb County, 3 miles north of Mt. Clemens, then plowed east northeast across New Baltimore to just north of Algonac, in extreme southern  St. Clair County, before crossing the St. Clair River into Canada. This tornado killed 11 people and injured more than 200 as it destroyed 132 homes and damaged another 240 homes and farms. But this tornado wasn't the most damaging in St. Clair County. That distinction belongs to an EF3 (136‑165 mph) tornado that hit St. Clair and Macomb Counties also in May...May 2nd, 1983. The tornado was again spawned over Macomb County, this time over the extreme southeast portion of the county near Eastpointe. The storm then blew across Lake St. Clair and into Harsens Island and damaged or demolished 25 to 30 homes, an aircraft hangar and a large building. The estimated cost of the damage was over $5 million.

Snow-OH !

 

While a few snow flurries or snow showers are all not that rare in Southeast Lower Michigan in the month of May, the following two snowstorms were and both I wrote in-depth about; here!
One storm occurred May 21st‑22nd, 1883, while the other, the more documented of the two, hit the area May 9th, 1923. The snowstorm on May 9th, 1923 was probably the most severe and extensive over Southeast Lower Michigan of the two ( I wrote in‑depth article on this storm very early in my Weather Historian career. 1996 titled "Snowstorm of May 9th, 1923").  Records at Detroit show a six‑inch snowfall by the evening of the 9th, while further north and west of the city it was even worse! Six to nine inches fell across the Ann Arbor area north into Howell and east, across Pontiac and Port Huron. Even more incredible, snow depths flirting with a foot were observed from Lansing and Flint area, north into the Saginaw Valley and Thumb Region. Widespread damage occurred when such a heavy wet snow fell on top of the newly sprouted spring vegetation. Afternoon and evening temperatures hovered in the lower to mid 30s, while a bitter cold (particularly for May) northwest wind blew at 15 to 25 mph.

The May 21st‑22nd, 1883 snowstorm by the date alone sounds almost unbelievable! Very little was written in the archaic Detroit weather records about the storm at the time. In fact, the snowstorm was not confirmed until much later (1904), since officially continuous snowfall records did not start until 1885. The following is from the official observation form...
                                                         May 21, 1883
            Rain began at 900am. Snow from 250pm to 910pm. Hail 934am to
           1005am and 110pm. Strong wind reaching 36 mph from the North.
           Temp from 32.5  to 46.0. Baro rising.
        
                                                         May 22, 1883
           Hail ended during the night. Snow began during the night. Rain and
           snow  ended 1005am. Northerly wind reaching 28 miles. Temp from 
           32.5 to 41.0  Snowfall estimated by Inspector Conger to have been
           5.0 in ‑ on 21st&22nd    (This entry made April 28, 1904 ‑ CDC.J)

The snowfall was split between the two days and recorded as 2.3 inches on the 21st and 2.7 inches on the 22nd. While hail was a likelihood, especially in the afternoon on the 21st as the colder air moved in, I suspect the hail recorded overnight into the 22nd could have well been graupel or sleet. One may also wonder with such cold air advected into the region at the surface and aloft in late May,  if thundersnow (sleet/hail) didn't also occur somewhere over Southeast Lower Michigan, especially with accumulating snow. The snowfall recorded on the 21st & 22nd in 1883 is by far the latest measurable snowfall recorded in Metro Detroit. The next closest, heaviest measurable snowfall date‑wise is 1.5 inches, which fell on May 13th, 1912 and then, our other big storm with the total of six inches on May 9th, 1923. The latest snow was officially observed in Detroit was the last day of May...May 31st, 1910 when a trace fell. By the way, it's interesting to note that not one of the pre-mentioned Mays with measurable snowfall placed in the top 10 coldest Mays in Detroit.


May Daily Snowfall Records
Date Snowfall (Inches) Year Date
1 0.3 1909 1
2 0.1 1909 2
3 0.1 2005 3
4 0.2 1907 4
5 0.0 2015 5
6 0.0 2015 6
7 0.0 2015 7
8 0.0 2015 8
9 6.0 1923 9
10 0.5 1902 10
11 0.0 2015 11
12 0.0 2015 12
13 1.5 1912 13
14 0.0 2015 14
15 0.0 2015 15
16 0.0 2015 16
17 0.0 2015 17
18 0.0 2015 18
19 0.0 2015 19
20 0.0 2015 20
21 2.3 1883 21
22 2.7 1883 22
23 0.0 2015 23
24 0.0 2015 24
25 0.0 2015 25
26 0.0 2015 26
27 0.0 2015 27
28 0.0 2015 28
29 0.0 2015 29
30 0.0 2015 30
31 T 1910 31


Heatwaves


Now, from one extreme to another, lets look at Heat Waves. While there have been hot days in May with records into the 90s, there are only two years that had extended periods of hot weather in May and those are 1962 and 1977. The hottest and more consecutive of the two was in 1962 when from May 14th‑May 18th, the daily high temperature climbed to ninety or above. This hot spell created five new consecutive record high temperatures which still stand to this day. In 1977, there were also five new record highs established but they were not consecutive, nor all in the 90s up until 2007 & 2012 when two were superseded (see: Tables, below). Very recently (in climate terms) May of 2012 was a very warm month and had its share of records also.

May - Detroit Records 1874 - Present
May Normals
(1980-2010)
Maximum Minimum Average Daily
Temperature
Precipitation
Date Max Min Avg Record
High
Lowest
Max
Highest
Min
Record
Low
Highest Lowest Greatest Date
1 65 45 55.0 86/1942 40/1909 70/1942 26/1978 78/1942 35/1909 1.46/1875 1
2 66 45 55.0 85/2012 39/1940 64/1942 29/1978 73/1942 34/1875 1.66/1892 2
3 66 45 56.0 89/2012 40/1929 64/1955 28/1978 76/1955 38/1957 1.31/1997 3
4 66 46 56.0 89/1949 45/1954 66/1955 28/1966 77/1955 39/1954 1.05/1990 4
5 67 46 56.0 90/1895 42/1917 70/1949 29/1891 80/1949 38/1917 0.85/1991 5
6 67 46 56.0 90/1949 46/1935 66/1941 31/1974 74/2000 40/1974 1.75/1976 6
7 67 46 57.0 86/2000 40/1947 68/1964 27/1974 77/2000 36/1947 0.97/1948 7
8 67 47 57.0 87/2015 38/1947 68/2000 30/1976 77/2000 34/1947 0.85/1974 8
9 68 47 57.0 90/1896 39/1923 68/1965 29/1983 79/1896 35/1923 2.12/1875 9
10 68 47 58.0 90/1936 42/1902 67/1896 25/1966 78/1896 38/1966 2.33/1948 10
11 68 48 58.0 87/1993 43/1960 67/1881 30/1907 76/1896 39/1907 1.91/1914 11
12 69 48 58.0 90/1881 44/1966 65/1881 32/1934 78/1881 39/1895 1.48/2002 12
13 69 48 59.0 89/1977 45/1888 66/1956 30/2013 77/1991 41/1910 1.48/1991 13
14 69 49 59.0 91/1962 40/1895 66/1962 34/1984 79/1962 39/1895 1.39/1916 14
15 70 49 59.0 92/1962 48/1945 71/1962 33/1973 82/1962 42/1895 1.46/1923 15
16 70 49 60.0 92/1962 47/1945 70/1962 32/1984 81/1962 44/1957 1.09/1945 16
17 70 50 60.0 93/1962 48/1916 67/1962 31/1973 80/1962 43/1973 1.22/1980 17
18 71 50 60.0 93/1962 48/1915 70/1962 32/1973 82/1962 43/2002 1.50/2000 18
19 71 50 61.0 91/1934 40/1894 69/1996 32/2002 80/1996 37/1894 1.68/1949 19
20 71 51 61.0 91/1977 48/2002 68/1934 33/1981 79/1934 42/1895 1.56/1959 20
21 71 51 61.0 92/1977 46/1917 71/2013 32/1883 80/1934 39/1883 1.69/2004 21
22 72 51 62.0 90/1994 41/1883 67/1941 32/1883 78/1941 36/1883 1.14/1949 22
23 72 52 62.0 89/1964 46/1917 71/1964 34/1935 80/1964 40/1917 1.69/2004 23
24 72 52 62.0 87/2007 44/1925 67/1991 33/1925 77/1933 39/1925 1.26/1950 24
25 73 52 62.0 90/2012 47/1979 70/2012 35/1992 80/2012 45/1979 1.67/2011 25
26 73 53 63.0 92/1944 47/1961 70/1991 36/1983 79/1914 43/1961 2.56/1968 26
27 73 53 63.0 91/1941 51/1906 71/1941 35/1915 81/1941 46/1915 1.68/2014 27
28 74 53 64.0 95/2012 52/1930 72/1941 35/1907 82/1941 46/1894 2.02/1935 28
29 74 54 64.0 92/2006 48/1889 70/2006 32/1966 81/2006 42/1889 1.65/1876 29
30 74 54 64.0 93/1942 44/1889 73/1929 36/1966 81/1929 40/1889 2.27/1889 30
31 75 55 65.0 95/1895 46/1910 71/1919 34/1910 83/1895 26/1898 1.98/1946 31

Normal High: 69.9

Normal HDD: Month: 208

Normal Monthly Precip: 3.38
Normal Low : 49.4 Normal HDD Season: 6092 Normal Yearly Precip: 12.54
Normal Mean: 59.7 Normal CDD: Month: 42 Ave Snow this Month : -1.0

Normal CDD Season: 48 Ave Snow for the Season: 42.7

Precip: Greatest Monthly Total: 8.46/2004

Snow: Greatest Monthly Total: 6.0/1923
Precip: Least Monthly Total: 0.43/1920 Snow: Least Monthly Total: 0.0/na
                            1962                                                                     1977
DATE.............RECORD HIGH..........................DATE..............RECORD HIGH
5/14                         91                                        5/13                          89   
5/15                         92                                        5/20                          91
5/16                         92                                        5/21                          92
5/17                         93                                        5/24                          87/equaled & superseded 2007/
5/18                         93                                        5/25                          89 /superseded by 90 2012/
        
Both Mays placed in the top ten hottest Mays in Detroit with 1962 placing 5th and 1977 placing 8th with recent editions of 2015, 2012, 1998 & 1991. Ironically; May of 1991 placed at the top of the list for the warmest May but ironically, not one record high temperature was set that month.

Top 20 Coldest/Warmest Mays in Southeast Lower Michigan
Rank Detroit Area* Flint Bishop** Saginaw Area***
Coldest Warmest Coldest Warmest Coldest Warmest
Temp Year Temp Year Temp Year Temp Year Temp Year Temp Year
1 51.1 1907 66.5 1991 48.7 1997 65.0 1982 49.8 1924 64.6 1977
2 51.3 1917 65.5 1998 50.0 1966 65.0 1936 49.9 1945 64.0 1998
3 51.8 1967 65.3 2012 50.6 1967 64.7 1934 50.0 1917 63.4 1975
4 51.9 1966 65.3 1896 50.6 1945 64.4 1922 50.2 1997 63.2 1991
5 52.0 1997 65.2 1962 51.5 1984 64.2 1991 51.3 1947 62.8 1936
6 52.1 1924 64.7 1911 51.9 1947 62.9 2015 51.6 1967 62.7 1934
7 52.5 1945 64.5 2015 52.5 1961 62.9 2012 51.6 1915 62.5 1982
8 52.6 1935 64.4 1977 52.6 1973 62.9 1998 51.8 1925 62.5 1922
9 52.7 1882 64.3 1881 52.7 1954 62.7 1987 51.9 2002 62.2 2012
10 53.1 1915 64.2 1982 52.9 1968 62.6 1977 51.9 1983 61.6 2015
11 53.8 1947 63.7 1964 52.9 1924 61.9 2013 51.9 1954 61.5 2013
12 53.9 1910 63.7 1880 53.1 2002 61.9 1939 52.1 1966 61.5 1962
13 54.2 1883 63.6 2013 53.4 2005 61.8 1975 52.5 1946 61.3 2010
14 54.3 1888 63.3 1987 53.5 1983 61.6 1965 52.7 1935 61.1 1964
15 54.4 1983 63.3 1944 53.8 1974 61.5 1962 52.8 1948 61.1 1959
16 54.5 1984 63.1 1965 53.8 1948 61.4 1944 53.0 1974 61.0 1985
17 54.5 2002 63.0 1887 54.0 1957 61.1 1933 53.1 1956 60.7 1965
18 54.5 1890 62.8 1975 54.1 1963 61.1 1921 53.4 1957 60.5 1988
19 54.7 1954 62.8 1936 54.1 1935 60.9 1959 53.4 1923 60.4 1987
20 54.7 1925 62.8 1922 54.1 1925 60.9 1941 53.6 2003 60.4 1941
* Detroit Area temperature records date back to January 1874.

** Flint Bishop temperature records date back to January 1921.

*** Saginaw Area temperature records date back to January 1912.


Try to enjoy May's weather whatever it brings!   

Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian

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