Michigan registers warmest winter on record
By Katie Alvord
HOUGHTON -- A few days before the arrival of March with some near-blizzard
conditions, Marquette climatologist Kevin Crupi thought this winter's Upper
Peninsula temperatures might set a new record for warmth.
Crupi was close. As the meteorological winter ended last Thursday, average
temperatures at National Weather Service (NWS) headquarters for the Upper
Peninsula, where Crupi works in Marquette, fell just under the record. But for
the state of Michigan as a whole, preliminary numbers do now indicate this was
the warmest winter ever measured. And temperatures collected at Michigan
Technological University have yielded well-above-normal monthly averages since
|Swedetown Creek meanders along the Maasto
Hiihto Ski Trail in Hancock. Weather observers say warmer
temperatures this year have resulted in lower snowpacks despite
higher snowfall in some areas. (Late January 2002 Keweenaw Now
"It's certainly been one of the mildest winters I've seen since moving
up here 25 years ago," says Jim Carstens, a retired MTU professor emeritus
who tracks the weather data at MTU for the NWS.
The MTU measurements include average high and average low temperatures for
each month. As of November 2001, Carstens says, the temperature data started
"getting kind of funny." That month proved to be the warmest November
measured in nine-plus years of record-keeping at MTU, and by a wide margin.
November's average high of 51.2 degrees was nearly 11 degrees warmer than the
40.8 degree nine-year average for the month in that location. The average highs
and lows at MTU have been above normal each month since then (see table).
high and low temperatures
(Measured at MTU)
Avg high this season
Avg high over 9 yrs
Avg low this season
Avg low over 9 years
-- All figures in
-- Nine year averages for each month calculated using data
collected since MTU weather station was opened in 1993.
Lake Linden meteorologist John Dee confirms that this winter's weather has
been marked by higher temperatures, but also higher snowfall in some locations.
The warm temperatures, though, have caused much more melting of snow, especially
in low areas and near Lake Superior, resulting in lower snowpacks.
"That's been the main theme of this winter," says Dee.
At his Lake Linden station, Dee has measured slightly higher than average
snowfall so far this season. As of the end of February, he'd measured 184 inches
of snowfall, compared to a fifty-year average of 176 inches by that date at the
nearby Houghton County Airport.
Winter 2001-2002 mild across Midwest
As far as temperatures go, this winter has been a record mild one across much
of the Midwest according to Jay Lawrimore, chief of the Climate Monitoring
Branch of the National Climatic Data Center (NCDC) in Asheville, North Carolina.
Preliminary calculations show that ten states from the Plains to the Northeast
-- including Michigan, Wisconsin and Iowa -- have had their warmest winters on
record. Minnesota registered its second warmest December through February. For
the whole country, this ranks as the fifth-warmest winter on record, says
Climate and weather agencies define December through February as
meteorological winter, but if they throw November into the mix even more records
tumble. NOAA (the National Oceanic and Atmospheric Administration, the parent
organization of the NWS and the NCDC) has already announced that the three
months of November 2001 through January 2002 broke a record for the warmest such
period ever measured across the entire United States. And the last four months
have been the warmest November through February on record in Marquette, with the
average temperature hitting 27.2 degrees.
That's three degrees warmer than the previous record for those four months, a
significant difference when many weather records are broken by tenths of a
"That speaks volumes about how warm it's been here," says Crupi.
Crupi reports that the Marquette NWS station's average temperature for the
three winter months, December through February, was the second highest on
record, at 23.0 degrees. The warmest average winter temperature in Marquette,
23.4 degrees, occurred during the El Niño
winter of 1997-98.
This winter is "in keeping with the trend since the late nineties of
very mild winters" in our region, says Crupi. Of the last five winters
here, all but the 2000-2001 season have fallen onto the list of the region's top
six warmest winters.
In general, Crupi adds, our warmer winters have also tended to be more snowy.
This year, Marquette has measured one of its snowiest winters, and February set
a record for the snowiest month ever. A total of 91.9 inches fell last month at
the Marquette station, which is located about 800 feet higher than the Lake
Superior shoreline in Negaunee Township.
At MTU, on the other hand, snowfall is running below normal at 121 inches so
far this year, when the average total for the season is 165 inches at that
Like John Dee, Crupi observes that this winter's higher temperatures have
contributed to lower snowpacks particularly in low areas and near shorelines,
such as MTU's location.
The warmer temperatures seen at MTU are part of a trend observed since that
weather station began data collection in 1993.
MTU's Carstens has also witnessed warm temperatures this late fall and
"There's a definite warm-up that's occurred just over the last nine
years," he notes. "The trend is a gradual increase in both high and
low average temperatures."
Carstens hesitates to say whether this might indicate climate change.
"It does seem to support the idea, and you can certainly make an
argument for that," he says. "But it's a very debatable subject, and
nine years is a very short period on which to base any conclusions."
John Dee agrees that whether or not this winter's "phenomenally
warm" weather has to do with climate change is hard to pin down
"It's possible that the warm temperatures we've seen are part of a
bigger-picture warming of the atmosphere, but that's a tricky call," says
Experts note trend toward global warming
The NCDC's Lawrimore notes a worldwide trend toward warmer temperatures.
"You never really can look at a single season or single weather event
and say it's due to climate change," Lawrimore says. "But, having said
that, we have seen a trend toward warmer temperatures in the U.S. and around the
globe in the last century."
Lawrimore adds that "the data show a significant amount of warming as
well as other changes that are consistent with what you'd expect to occur in the
climate when you have an increase in carbon dioxide and other greenhouse
The International Panel on Climate Change (IPCC), an international body
involving thousands of scientists who have studied and reported on these issues,
has found that at least a portion of the warming is due to human activities,
Lawrimore explains. At NOAA, he says, "we don't differ from that
Average temperatures, he states, have gone up about 1 degree Fahrenheit in
about the last hundred years. And in the last 25 years, average temperatures
have risen at a rate that's equivalent to three times faster than that.
Research by Elise Ralph of the Large Lakes Observatory in Duluth suggests
that Lake Superior, too, has warmed over the last century, by about 0.5 degrees
Centigrade. MTU Associate Professor of Chemistry Sarah Green, who works with
Ralph in the KITES project (an interdisciplinary study of the Keweenaw Current
in Lake Superior), points out that "even a slight warming of the lake could
change our weather" locally. She adds, "Lake Superior acts as a huge
local heat reservoir. In the long term, warming of the lake could also delay the
onset of winter weather because it will take longer to cool the surface water in
A pattern of delayed winter onset does seem to have occurred this year.
November set a record for warmth, December saw little snowfall until just before
Christmas, and, says John Dee, "the whole month of January was spring-like,
with snow and periods of melting."
The beginning of March this last weekend saw the most winter-like weather
we've had all year, he observes.
Despite the chilly first few days of this month, forecasters do expect
temperatures to warm again. Long-term forecasts predict above-normal
temperatures for March overall, as the jet stream shifts into a position that
will bring more mild weather to the U. P.
And there may be more warmth in the region's future. Scientists predict the
possible return of El Niño later this year.
This condition of above-normal temperatures in the eastern equatorial Pacific
Ocean typically brings warmer, drier weather to the Upper Midwest. By this
summer, observers expect to know whether El Niño
will actually materialize, and if it does, how strong this particular El Niño
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