Originally written September 1999 & Updated September 2004/2012/2013 (see updated reanalysis information).
This week is the anniversary of one of the most unusual
and intense wind storms ever to hit Southeast Lower
Michigan. It was over seven decades /72-yrs/ ago on September 25th, 1941
when the remnants of a tropical storm hit the region. This storm by far, was not the
usual remnants of tropical origins that occasionally make it up to the
Great Lakes region but one of extraordinary circumstances for it truly was the Astonishing Storm of September 25th, 1941
At first glance, when one reads that headline, one might say, "What?
Hurricanes here in the Great Lakes?? No way!" Of
course you'd be right, no actual hurricane has ever been observed in Michigan
under the true definition of a hurricane. The definition of a hurricane, according
to the
Glossary of Weather and Climate edited by Ira W. Geer,
is as follows: "A severe tropical cyclone with maximum 1-minute sustained
surface wind speed greater than 64 knots (74 mph) in the North Atlantic Ocean,
Caribbean Sea, Gulf of Mexico and the Eastern North Pacific off the west coast
of Mexico to the International Dateline. West of the Dateline they are known as
typhoons." Furthermore, the definition of a tropical cyclone is as
follows: "A generic term for a non-frontal synoptic-scale cyclone
originating over the tropical or subtropical waters with organized convection
and a definite cyclonic surface wind circulation." Clearly, neither
definition applies in the Great Lakes area, although
remnants of hurricanes that have become extra-tropical (loses its tropical
characteristics) occasionally do make their way into the Great Lakes
region.
Scanning over 80 years (since 1921) worth of hurricane track
data suggests that remnants of
a hurricane or tropical storm make their way into the Great Lakes region on an
average of twice a decade, especially the southern Great Lakes area (see
Table-1). Also, in the majority of instances, by the time they visit this
region they have diminished to an area of rain with maybe some squally winds.
There have been a few instances, along the way, however, that do bear
mentioning, and ONE STORM in particular that screams for attention!
TABLE - 1
REMNANTS OF
TROPICAL STORMS THAT HAVE AFFECTED THE GREAT LAKES AND SOUTHEAST
LOWER MICHIGAN (SINCE 1921)
|
DATE
(Storm's life cycle)
|
DETROIT
RAINFALL/DATES (Inches)
|
MAXIMUM
WIND (mph)
|
|
10/16-19 1923
|
.55 - 10/18
|
SE - 22
|
|
7/20-8/2 1926
|
1.11 - 8/1
|
E - 25
|
|
8/27-9/3 1932
|
2.95 - 9/3-4
|
NE - 21
|
|
9/10-22 1938
|
.23 - 9/21-22
|
SW - 20
|
|
9/16-25 1941
|
Trace - 9/25
|
SW - 52 *
|
|
9/1-6 1948
|
.82 - 9/6-8
|
N - 25
|
|
9/27-10/6 1949
|
1.30 - 10/6-7
|
SW - 21
|
Connie -
|
8/1-8/14 1955
|
.69 - 8/13-14
|
W - 20
|
TD ** -
|
6/22-6/28 1960
|
.31 - 6/28
|
SW - 23
|
Carla -
|
9/3-9/15 1961
|
.13 - 6/14
|
W - 29
|
Candy -
|
6/22-26 1968
|
2.55 - 6/24-26
|
NE - 30
|
Hugo -
|
9/10-24 1989
|
Trace - 9/22-23
|
NW - 38
|
Opal -
|
9/27-10/6 1995
|
1.41 - 10/5-6
|
N - 38
|
Fran -
|
8/23-9/8 1996
|
.99 - 9/7
|
NW - 25
|
Isabel -
|
9/6-9/19 2003
|
0.25 - 9/18-19 #
|
W - 33
|
Ike - 9/1-9/15 2008 3.78 - 9/13-14 N - 43
* denotes officially at Detroit City
Airport, but gusts were clocked
up to 75 mph across the Metro Detroit area.
** TD - Tropical Storm
# Up to 2.50" reported along the St. Clair River
|
>>
Note; Hurricane Sandy's path /2012/ did not pass over/near Southeast Lower Michigan<<
First off, under the "mention" category in
1932 (well before hurricanes
were named), a hurricane that developed in the Caribbean on August 27th,
tracked northwest into the Gulf of Mexico, then generally north, across
Alabama, eastern Arkansas, southeast Missouri, into southern Illinois and then
from there, headed northeast across Indiana into Southeast Lower Michigan. The
storm approached Southeast Lower Michigan late on
September 3rd. A light to moderate northeast wind proceeded the storm on the
2nd and 3rd averaging around 11 mph with gusts into the lower 20s, hardly
anything noteworthy wind-wise. The storm did however, pass right over Detroit,
causing the barometric pressure to fall from around 30.20 inches early on the
2nd to around 29.60 late on the 3rd. Rain began to fall lightly but steadily
early in the morning on the 3rd, but from mid afternoon into the evening,
moderate to heavy rain fell and by midnight, over two and a half (2.55) inches
was dumped on the Detroit area. Close to an additional half inch or so of rain
was added to that on the 4th for a total of nearly three inches.
Another "mentionable" was odd from the start because of its
timing, occurring very early in the season during late June of
1968 (only one other June
system was found since 1921 to have affected the Great Lakes: the weak remnants
of a tropical storm that moved from the Gulf of Mexico to near Chicago, June
22-28th, 1960). On June 22, 1968,
Tropical Storm Candy formed off the coast of eastern Mexico
and then headed north into southeast Texas,
just north of Corpus Christi. She
then weakened, headed north-northeast through eastern Texas
and Oklahoma, central Missouri
and Illinois, then she pivoted on
a more easterly track across northern Indiana
into extreme northwest Ohio, over
Toledo. Candy began to influence Southeast
Lower Michigan's weather on the morning of the 25th. A nearly
steady rain, interspersed with a few thunderstorms, continued through the day
and evening, depositing nearly two and a quarter (2.17) inches. More scattered,
lighter showers fell on the 26th, adding another .38 to give a grand total of
2.55. Through it all, an east to northeast wind blew averaging 10 to 14 mph
with gusts into the 20 to 30 mph range.
A more recent storm (and last under the mentionable category) was fairly
impressive as it wound its way north out of the Gulf of Mexico, through
Alabama, Tennessee, Kentucky and into Northern Ohio. She was known as Hurricane
Opal and had a 10-day life span from September 27th to October 6th,
1995. On the
evening of Oct 5th at 8pm, the
remnants of Opal were located over the eastern Great Lakes.
What was left of the "eye", or center of the storm, was well
indicated on the NWS Doppler radar in White Lake (DTX). The radar showed the
"eye" over Sandusky, Ohio
moving north out over western Lake Erie. Light to
moderate rain, with isolated areas of heavy rain, extended from Southeast
Lower Michigan east across Southwest Ontario
and Northeast Ohio. Spotty light rain first made an
appearance in Southeast Lower Michigan earlier in the
day, during the forenoon hours. During the afternoon, steadier rainfall
developed with the heaviest rain (.54) falling between 5pm and 7pm. The
rain ended just after midnight with a
total of 1.41 inches falling from the storm. With the approach of the storm on
the 5th, a generally north wind picked up and averaged over 15 mph with gusts
up into the 30s (peak wind gust was 38 mph)
One of the more recent Hurricane remnants to affect the area was Isabel,
which moved quickly through the Eastern Great Lakes on September 18-19th,
2003.
Rainfall from the system
was quite variable ranging from just a trace over far western areas of Southeast
Michigan, to as much as 2 1/2 inches at local spots along the St.
Clair River. In 2008, remnants of Hurricane Ike brought very heavy rains to the region along with strong winds and a
brief F2 over western Wayne County.
The Astonishing Storm of September
25th, 1941
Earlier, I mentioned "one storm that screams for attention", but
maybe "howls" would be more appropriate. Before researching this
project, I expected to find the above case scenarios, but not the following...
Recently /2013 changes/ the Hurricane Research Division /HRD/ did a reanalysis of the hurricane and its associated track and wind speeds. *Note the asterisks in the following storm account are adjusted for those changes. (Thanks to Hoosier, moderator of American Weather for the heads up on the reanalysis)
* The storm made landfall in Texas as a category 3
* After moving onshore and through its entire remaining path, the storm was upgraded by maintaining tropical force
winds as she evolved from a tropical storm to extra-tropical.. Also note the slightly westward track depicted over upper
Ohio Valley and Lower Great Lakes in Indiana and Michigan.
Comparing the two tracks;
Original
Reanalyzed
A tropical storm (#2 on original analysis map &
#17-under 19-21, unseen on reanalyzed) formed in mid September over the Gulf of
Mexico on
September 17th, 1941. As it formed it meandered over the Gulf, making a loop in its track, well south of New
Orleans. By this time it was a hurricane, intensifying
briefly to a category #3 storm (111-130 mph wind) offshore as it took aim on
eastern Texas. The hurricane made
landfall late on the 23rd near Freeport, Texas
with an estimated wind of a
category #3* (111-130 mph), extremely high tides of nearly 11 feet and a
barometer reading of 28.31 inches (959 MB). Further to the northeast, a ship
just offshore of Texas City
recorded a lowest pressure of 28.66 inches and winds of 83 mph. Other wind
gusts were estimated near 100 mph at several locations near the hurricane's center
along the Texas Gulf
Coast. The hurricane quickly
weakened to a category #1 (74-95 mph) as it made landfall and by the time the
storm pushed on north to Houston, wind gusts had already dropped to 75 mph.
Four lives were lost from the storm in Texas
and property damage was estimated at $6.5 million (1941 dollars).
The storm continued to roar on its northward path through Texas
and by 7 am on the 24th, it was
located near the city of Tyler,
over extreme northeast Texas.
From this point on, the storm's last 36 hours or so really grabs ones interest
for peculiarity as it tracked through the Mississippi
Valley and on into the Great
Lakes. From 7AM on the 24th to 7am
the 25th, the storm shot northeast from Tyler
to near Battle Creek, Michigan,
covering close to 1000 miles in 24 hours! Thus, the forward movement of the
remnants of the hurricane averaged 40 to 45 mph as it approached Southern
Lower Michigan. As the storm tracked into the Great
Lakes, it merged with a fairly strong cold front that pushed
across the upper Midwest into the Lakes. The combination
of the strong push of cool fall air, strong upper level dynamics and the
remnants of the hurricane created quite a storm (not unlike the more common
intense late fall cyclones that are seen in the Great Lakes).
In addition, the track and speed of our "hurricane" brings to mind
that of the "Panhandle Low" type of low pressure system in the winter
(
more information). While
the speed of the system was fairly quick, it's not uncommon for hurricanes to
accelerate northeast as they become extra-tropical and get "picked up"
by the mid-latitude upper winds or jet stream. Yet, what was really unusual and
noteworthy was the surface wind that accompanied the storm as it moved through
the Great Lakes. By the time hurricanes make it this far
north, they usually have blown themselves out, at least to the extent that
surface winds are only gusting to, at best, 30 or 40 mph. Note the following,
taken from the Detroit weather records on September 25th, 1941:
Windstorm: An intense tropical cyclone moving up from
the Gulf thru eastern Texas
(causing great damage in Texas),
along the Missip. Valley and thence Newd across Ill & Mich, passing W &
NW of Detroit with gale force winds and gusts to 65 mph from 10:18 AM - 2:30 PM
& gusts to 75 mph 12:30 PM - 2:00 PM (see envelope back of book for
newspaper clippings).
Most of the above noted news clippings show widespread wind damage to trees
and power lines that would be commonplace in severe thunderstorms or a derecho.
A
derecho
is a widespread windstorm consisting of a complex of thunderstorms that develop
into a long-lived squall line. But there also were some unusual or freakish
happenings (as the Detroit Free Press deemed them) as well. The following is
taken September 26th, 1941,
the day after, from the Detroit Free Press about the storm:
"River goes
dry"
There were many freakish effects of the wind, including baring of the Detroit
River
"middle grounds" off Belle Isle when water was backed into Lake
St. Clair. The southwest gale literally blew the water
out of The Detroit River,
reducing its level by three feet, and leaving hundreds of pleasure craft high and
dry on the muddy bottom. Several yachts broke their mooring or were heeled over
at the Detroit
Yacht Club. Another odd effect was the noticeable swaying of Downtown
skyscrapers as the full force of the gale struck. Office employees who left
tall downtown skyscrapers, were later reassured by engineers.
The Free Press goes on to say that "shortly after noon, the wind blew steadily at 56 miles an hour, but a
times gusts reached hurricane velocity of 75 miles an hour." Dozens of
people were injured by falling glass from windows blown out or debris tossed by
the wind. One woman was literally blown into a fire hydrant, suffering a
possible skull fracture. Other reports of scattered damage to homes and
businesses across the region were mentioned in the article. In addition, the
fierce wind churned up giant waves on the Lakes, including Lake
Huron into the St. Clair River where two barges were blown ashore
from of the shipping channel, even after dropping their heaviest anchors. In Southeast
Lower Michigan, Storm Warnings were posted on Lakes
Huron, Erie
and St Clair at 10:30, the morning
of the 25th. Downed telephone lines caused a disruption of service and
communication across the Great Lakes and elsewhere. The
"dying" hurricane left a trail of damage from Texas
clear up into the Great Lakes and Canada.
The wind of the storm was equated to an intense fall low pressure system that
hit the area on November 29th, 1919
in which the wind blew 67 mph in Detroit
and to the "Black Friday" storm in
November of 1913.
The fact that the hurricane, after weakening and becoming extratropical,
traveled over a thousand miles and still was able to maintain that much wind is
extraordinary in itself. As the storm moved into Southern Lower
Michigan, its center tracked northeast across Battle
Creek, Lansing,
Saginaw and then out over Lake
Huron and into Ontario.
Judging by the lowest pressure readings at Detroit (29.25 inches) and Flint
(29.17 inches), where the wind gusted to 69 mph, its central pressure was
estimated to around 29.10 inches (about 985 MB). Quite impressive for the
remnants of a "dying" hurricane in the Great Lakes
in September. In fact, this is the second lowest pressure reading ever recorded
in Detroit during the month of September (the first being 29.21 inches on Sep
29th, 1966, during the passage of an intense early fall low pressure system).
One can only make a random guess as to the chances of another
hurricane-force wind storm, from remnants of an actual hurricane, hitting the Great
Lakes again. Since it was the only one of its kind in the record
books at Detroit since records
began in 1870, it may take several 100 years before another similar storm
affects the region!
Hurroncane
One final, extremely interesting "hurricane" that affected the Great
Lakes must be mentioned to make this article complete. While this
storm was not from remnants of a tropical system, its development over Lake
Huron had many uncanny likenesses to tropical systems...
The first likeness was its timing, forming over the Great Lakes
right at the height of the typical hurricane season, September 11-15th, 1996. What started as a
typical
core-cold 500 MB
low pressure system evolved into a
warm-core system as it
settled over the relatively warm waters of the Great Lakes,
in particular, Lake Huron. The low pressure system
actually had moved past Lake Huron but then retrograded,
or was "drawn back", to the relatively warm waters of Lake
Huron. (Similar to the tropics, the Great Lakes
usually reach their warmest water temperatures late August into mid September.)
The storm then deepened and intensified at the lower levels of the atmosphere
compared to aloft, typical of a warm-core low. It is believed that the warm
waters of Lake Huron and associated low level
instability over the lake were, to a large extent, the major contributing
factors in this storm's evolution. The storm went on to form a broad cyclonic
circulation, including the "spiral bands and eye", typically seen in
hurricanes! At one point, the cyclone produced tropical storm force winds (39 -
73 mph) and some of the spiral bands even had rainfall exceeding 10 cm (better
than four inches), causing some flooding.
On satellite, the storm looked very much like the classic hurricane
picture:
This "Hurroncane" reached its maximum intensity during the day on
September 14th, when a central pressure of 29.34 inches (993 MB) was recorded
in the late morning by a Lake Huron buoy that
fortunately was positioned, at one point, in the "eye". By 2 PM, that "eye" measured close to 20
miles across and had a ring of tall convective clouds surrounding it, strongly
resembling that of an "eye wall". The convective showers encircled
the "eye" well out over 300 miles. As the "eye" moved to
the southwest (retrograded), over the aforementioned buoy, the surface wind
backed from west at close to 35 mph to the southeast, and then diminished to
near 10 mph. After, the "eye" continued to track to the southwest,
away from the buoy, and the surface wind backed further to the northeast, and
briefly attained tropical storm force. A similar scenario but with varying wind
speeds, would also be expected at the ocean's surface if a tropical system
retrograded from northeast to the southwest overhead. In addition, the air
temperature rose from 13°C (55°F) in the spiral shower bands, to near 18°C
(64°F), which was also the lake temperature, in the clearing above the
"eye". The storm weakened overnight as the lake temperature dropped
5°C (9°F). The lower water temperature helped greatly in weakening the storm as
a result of the lower latent heat supply.
For additional information on hurricanes, check in with the National Hurricane Center.
Background on "Hurroncane" was provided by a paper entitled
"Hurricane Huron" by Mr. Todd Miner of Pennsylvania
State University
along with Dr. Peter Sousounis, Dr. Greg Mann and Mr. James Wallman of the University
of Michigan.
Making weather fun while we all
learn,
Bill Deedler
- SEMI_WeatherHistorian
