I wrote this article BEFORE last March's record warmth. Still,
it is a very interesting account of that March of 1945...and
also, the spring that followed it! Ironically, a similar wide-
spread severe crop damage occurred back in April of 1945 like
last April's; due to cold and frosts. And, that was only a
portion of that spring's (not to mention the previous winter's)
weather issues! Enjoy...
MILD MARCH MADNESS - 1945
When looking through the month of March records in Southeast
Lower Michigan, one can't help but notice March 1945. The
temperature departure alone is awesome. March of 1945 made
the record books as the warmest March ever, before and since
(1870-1996) in Detroit. The average temperature of 47.9 (all
right, let's cheat and say 48 degrees) is extraordinary in
itself when considering the current normal, or average,
temperature in Detroit for March is 35.7 degrees. In 1945
however, the normal was even lower at 33.0 degrees (normals
for Detroit have been rising through the years). March of
1945's average or mean temperature not only surpassed the
current March's normal temperature by more than 12 degrees
(+12.2), the 1945 normal by nearly 15 degrees (+14.9) but
even bettered the current April's normal by about a half
degree (normal mean for April in Detroit is 47.3).
Well, you might ask "Did this LAMB of a month start out and
end that way?" Yes, right from the start there were no LIONS
to be seen this March. During the first few days of the month,
temperatures averaged about 10 degrees above normal, while
near the end of the month, readings averaged 15 to as much as
30 degrees above normal(see Table-1). Other temperature facts
during the month which are just as outstanding are: only one
day during the month averaged below normal and that was only
by 2 degrees, over half the month's (17 days) high temperatures
were 60 or better with nine of those days rising to 70 or better
and one even climbing above the 80-degree mark (82)! Keep in
mind, the current normal high for March is only 44.4 degrees.
As one might expect, with all the warm weather there would
be some record high temperatures established and there were...
six (Table-1). It's also interesting to note that the highest
mean temperature during the month, 68 degrees on the 28th, is
normal for the first day of summer, while the high that day of
82 is about normal for the 4th of July!
Abundant sunshine during the month (66% vs the normal of 51%)
certainly aided strongly in establishing this record warm month.
Even though sunshine was above normal for the month, rainfall
was also, with three and a half inches falling. With above
normal heat and rainfall during the month, one might also think
that it would be an active thunderstorm/severe weather month.
The observations at Detroit indicate otherwise, with only two
days having thunderstorms. The thunderstorm activity remained
heavily concentrated to the south in the Ohio Valley.
Speaking of the weather pattern, lets take a look at the general
weather pattern that created such an unseasonably warm month.
Needless to say, with such a warm March, all the real Arctic
cold remained bottled up in Canada. This was due to a strong
west-southwesterly flow across the U.S. from the Pacific. This
strong predominant flow of mild maritime air kept any Arctic
cold high pressure areas well north of the region. The high
pressure areas that did move across the area were of Pacific
origin and thus, contained milder air.
The strong west southwesterly jet stream across the country
also kept an active storm track in place, but it was mainly
west and south of Southeast Lower Michigan. Several low
pressure areas and attending frontal systems moved east
northeast across the Ohio River region and dumped copious
amounts of rain, creating severe flooding in that area (not
unlike the early March storm track pattern of this year).
Rainfall amounts of eight to 14 inches in March were common
from the Arkansas area northeast across Kentucky and Ohio
into Pennsylvania. In fact, at least up until that time,
March of 1945 was the wettest month ever in Ohio. The low
pressure systems that moved west of Southeast Lower Michigan,
pulled very warm (for March) air north from the deep South
into the Great Lakes States.
The strong west-southwesterly flow over the country developed
a weak, but fairly persistent, ridge of high pressure over the
eastern third of the country. Therefore, for you meteorological
buffs, the 500 MB heights averaged above normal (540-542 meters
over the southern Great Lakes). At the 850 MB level (5,000 ft),
the average 0'C isotherm (32'f) was well north of Southeast
Lower Michigan, lying east-west across the tip of Northern
Lower Michigan.
In the end, it seems like Mother Nature always manages to
balance things out, as was the case this time. One can't
help but wonder if the people of the time felt a "payback"
was in the works for such a early, warm Spring. The Winter
and Spring of 1945 certainly brought their share of weather
extremes across the Great Lakes and Ohio Valley.
In addition to the warm March and severe flooding in the Ohio
Valley, the following was obtained from the "Monthly Weather
Review" Publication:
The year 1945 was notable for the severe cold
weather, record snowfall, and continuous snow
cover in the eastern portion of the country until
February; an abnormally warm March east of the
Rockies; and unfavorably cool, wet weather for much
of the remainder of the year- especially April, May
and June- in the central and northeastern sections.
Abnormal warmth prevailed during March over
practically the entire region east of the Rocky
Mountains. Temperatures averaged higher than for any
previous March on record for the States of Indiana,
Ohio, Michigan, New York, New England, New Jersey,
North and South Carolina. The month was extremely
wet in central parts of the country, especially the
Ohio and Mississippi Valleys, where disastrous
floods occurred. Unusual warmth and generally
adequate moisture caused vegetation to advance
rapidly over practically the entire region east of
the Rockies and by the end of March, the season was
from 2 weeks to a month ahead of normal.
The possibility of dangerous freezing, with
vegetation, especially fruit, at such a critical
stage of development so early in the season, became
a reality when from April 4-7 and on the 23rd cold
weather overspread central and eastern sections of
the county and brought severe frosts and freezing
southward as far as Oklahoma, Arkansas, the Ohio
Valley and many southern Appalachian regions, with
considerable damage to fruit and early gardens.
Continued wet weather from Oklahoma and Arkansas
to the Great Lakes, seriously delayed seeding and
development of crops, notably corn. One of the
worst April snowstorms of record occurred in Iowa
and some adjacent states on the 3rd and 4th. May
was unfavorably cool...especially in the northern
interior, with frosts in sections of the southern
Lakes Region as late as the 24th and 30th. An
unusual May snowstorm moved across the more northern
states with falls up to 8 inches in Iowa on the 9th,
and 10 inches to 2 feet in New England on the 10th
and 11th.
And there were the usual severe events and tornadoes but still,
a quite eventful and somewhat extraordinary Spring indeed!
By the way, What was the second warmest March on record in
Detroit you might ask? Believe or not...the next year, 1946!
-----------------------------------------------------------------
TABLE - 1 DETROIT MI - MARCH 1945
-----------------------------------------------------------------
DATE MAX MIN MEAN DEPART DATE MAX MIN MEAN DEPART
_________________________________________________________________
3/01 44 23 34 + 6 3/17 # 75 44 60 +27
3/02 42 38 40 +12 3/18 63 41 52 +18
3/03 53 29 41 +13 3/19 70 49 60 +26
3/04 40 25 32 + 4 3/20 61 37 49 +15
3/05 63 32 48 +19 3/21 45 35 40 + 5
3/06 53 27 40 +11 >(.3) 3/22 54 31 42 + 7
3/07 36 21 28 ** - 2 3/23 # 73 40 56 +20
3/08 39 24 32 + 2 3/24 63 39 51 +15
3/09 45 27 36 + 6 3/25 # 78 43 60 +24
3/10 38 29 34 + 4 3/26 73 51 62 +25
3/11 45 25 35 + 4 3/27 # 79 53 66 +29
3/12 52 35 44 +13 3/28 #*82 55 68 +30
3/13 53 30 42 +10 3/29 65 44 54 +16
3/14 67 36 52 +20 3/30 62 42 52 +13
3/15 70 46 58 +26 3/31 60 45 52 +13
3/16 # 74 56 65 +32
> ONLY SNOWFALL RECORDED
# RECORD HIGH (STILL STANDING, EXCEPT 3/23 TIED IN 1994)
* HIGHEST TEMPERATURE EVER RECORDED IN MARCH
**ONLY DAY BELOW NORMAL IN MARCH
Average Average Normal Departure
High Temp Low Temp Mean (1945) (1997) (1945) (1997)
58.6 37.2 47.9 33.0 35.7 +14.9 +12.2
Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian
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