The Exceptionally Mild Winter of 2001-2002 Did Manage to Throw Some
Punches Mid-Late Winter
Written by: William R. Deedler, Weather Historian
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THE WINTER OF 2001-02 WILL BE REMEMBERED AS AN EXTRAORDINARILY MILD
WINTER ACROSS SOUTHEAST LOWER MICHIGAN. IN EVERY WINTER MONTH, THE
TEMPERATURE AVERAGED WELL ABOVE NORMAL (SEE
CHART-1) WITH JANUARY
HAVING THE LARGEST ABOVE NORMAL DEPARTURE. THE EFFECT OF THE PACIFIC
MARINE AIRMASS (CLIMATE) IS REFLECTED WELL IN MUCH OF THE WINTER'S
WEATHER HERE IN SOUTHEAST LOWER MICHIGAN. AS RELATIVELY "WARM" AS
THE WINTER WAS, HOWEVER, IT DID NOT PLACE AT THE TOP OF THE WARMEST
WINTERS LIST AT DETROIT, FLINT OR SAGINAW. CONSIDERING JUST HOW MILD
THE WINTER WAS, THE TOTAL SNOWFALL AMOUNTS WERE STILL QUITE
EXCEPTIONAL IF PAST HISTORY IS ANY GUIDE. THIS WAS PARTICULARLY THE
CASE ACROSS THE SAGINAW VALLEY, WHERE SNOWFALLS HANDILY BEAT
WINTER SNOWFALL AVERAGES.
CHRONOLOGICALLY SPEAKING:
THE WINTER OF 2001-02 UNFOLDED JUST THE OPPOSITE OF HOW THE WINTER OF
2000-01
DID, WITH THE NICEST OF THE WINTER THE FIRST HALF AS OPPOSED TO
THE SECOND HALF IN 2000-01. THE WINTER OF 2001-02 STARTED OUT AND
BASICALLY REMAINED MILD RIGHT INTO FEBRUARY. DECEMBER'S TEMPERATURES
AVERAGED ABOVE OR WELL ABOVE NORMAL UNTIL ABOUT CHRISTMAS WEEK,
WHEN A CHANGE IN THE JET STREAM TO A NORTHWESTERLY FLOW BROUGHT
POLAR AIR AND BELOW NORMAL READINGS INTO THE REGION. STILL, EVEN WITH
THE COOL DOWN LATE IN THE MONTH, ALL THREE CITIES MANAGED TO PLACE IN
THE TOP 10 LIST FOR WARMEST DECEMBERS ON RECORD. THE AVERAGE
TEMPERATURE ACROSS SOUTHEAST LOWER MICHIGAN FOR DECEMBER WAS
ABOUT 34 1/2 DEGREES, OR A SOLID SEVEN DEGREES ABOVE NORMAL! MONTHLY
SNOWFALL TOTALS CAME BELOW NORMAL ACROSS THE ENTIRE REGION WITH
THE LARGEST BELOW NORMAL DEPARTURES ACROSS THE SOUTH. MUCH OF THE
SNOW THAT DID FALL, FELL DURING THE LAST WEEK OF DECEMBER IN TIME FOR
CHRISTMAS WEEK.
THE UNSEASONABLY MILD AIR THAT DOMINATED MUCH OF DECEMBER ALSO
HELD SWAY FOR NEARLY ALL OF JANUARY. TEMPERATURES ACROSS SOUTHEAST
LOWER MICHIGAN AVERAGED AN EXCEPTIONAL 8 1/2 DEGREES ABOVE NORMAL!
THE WARMEST OF THE MONTH, IRONICALLY, OCCURRED DURING WHAT IS
TYPICALLY THE COLDEST PART OF THE WINTER SEASON. RECORD HIGH
TEMPERATURES WERE SET LATE IN THE MONTH JUST BEFORE THE BOTTOM FELL
OUT BY WAY OF A DESTRUCTIVE WINTER STORM ON
JAN 30TH-FEB
1ST.
THIS STORM WAS REALLY THE FIRST OF A FEW BIG WINTER STORMS DURING THE
SEASON. SNOWFALL TOTALS FROM THIS STORM WERE QUITE VARIABLE,
RANGING FROM 2 - 4 INCHES OVER THE EXTREME SOUTHEAST CORNER OF LOWER
MICHIGAN (NEAR THE OHIO BORDER), TO AS MUCH AS A FOOT IN PORTIONS OF
WAYNE AND WASHTENAW COUNTIES, NORTH INTO FLINT AND LAPEER. SLIGHTLY
LESSER AMOUNTS OF 4 - 9 INCHES WERE FOUND ACROSS THE SAGINAW VALLEY
AND THUMB REGION. ADDING INSULT TO INJURY, A COATING OF FREEZING RAIN
FELL OVER EXTREME SOUTHEAST MICHIGAN AND INSTIGATED WIDESPREAD
POWER OUTAGES AND SUBSTANTIAL TREE DAMAGE. ICE ACCUMULATIONS OF
1/4 TO 3/4 OF AN INCH WERE FOUND ACROSS PORTION OF WASHTENAW AND WAYNE
COUNTIES WITH THE WORST IN A NARROW STRIP FROM THE ANN ARBOR AREA,
EAST INTO THE DOWNRIVER COMMUNITIES OF DETROIT. VERY STRONG WINDS
BEHIND THE STORM BUFFETED THE REGION AFTER THE STORM ON FEBRUARY 1ST.
INTERESTINGLY, THIS STORM ACTUALLY PUSHED SNOWFALL TOTALS UP TO
WELL ABOVE NORMAL AND HELPED LEAD TO AN UNUSUAL COMBINATION,
WELL ABOVE NORMAL TEMPERATURES AND SNOWFALL FOR A MONTH.
IN RETROSPECT, THIS STORM (AND CHANGE IN THE ASSOCIATED UPPER
WIND PATTERN) HINTED AT THE LATE WINTER BREAKDOWN OF THE MILD
UPPER WIND PATTERN THAT HAD DOMINATED THE REGION.
FEBRUARY, IN SOME RESPECTS, WAS A CARBON COPY OF JANUARY WITH
TEMPERATURES AVERAGING ANOTHER LARGE SIX DEGREES ABOVE NORMAL.
ALSO LIKE JANUARY, THE PEAK IN WARMTH WAS FOLLOWED BY YET ANOTHER
BIG WINTER STORM THAT DUMPED A HEAVY BLANKET OF SNOW ACROSS
SOUTHEAST LOWER MICHIGAN. GENERALLY, 4 - 8 INCHES OF SNOW FELL ACROSS
THE AREA ON THE
25-26TH
WITH THE HEAVIEST ACROSS THE NORTHERN SUBURBS
OF DETROIT. IN SPITE OF TEMPERATURES AVERAGING WELL ABOVE NORMAL,
AGAIN THE LATE MONTH SNOWSTORM HELPED PUSH UP THE FEBRUARY
SNOWFALL TO AROUND NORMAL TO A FEW INCHES BELOW.
SOME OF THE MOST IMPRESSIVE FRIGID BLASTS OF THE WINTER DID NOT OCCUR
IN A METEOROLOGICAL WINTER MONTH BUT IN A SPRING MONTH, MARCH (AND
NOT INCLUDED IN THE WINTER AVERAGE TEMPERATURE). MARCH CLEARLY
LIVED UP TO ITS REPUTATION AS CONFLICTING AIR MASSES RESULTED IN SOME
NOTABLE TEMPERATURE SWINGS, STORMS AND WINDS. A VERY STRONG ARCTIC
PLUNGE CONTAINING BELOW ZERO WIND CHILLS SWEPT INTO THE REGION ON
THE 3RD-4TH AND BROUGHT SOME OF THE COLDEST WEATHER OF THE SEASON
TO MANY LOCATIONS. A LOW OF 8 DEGREES AT DETROIT AND 1 AT SAGINAW ON
THE 4TH BOTH WERE THE COLDEST FOR THE SEASON. A SQUALL LINE OF SHOWERS
AND NEAR HURRICANE FORCE WINDS WAS TRIGGERED ALONG A STRONG ARCTIC
COLD FRONT ON THE 9TH. THIS LINE TOPPLED OR UPROOTED NUMEROUS TREES,
DOWNED POWER LINES AND LEFT OVER 150 THOUSAND ELECTRIC CUSTOMERS IN
SOUTHEAST LOWER MICHIGAN WITHOUT POWER. THE MOST NOTABLE SNOWSTORMS OF
MARCH HIT AT FAR REACHES OF SOUTHEAST LOWER MICHIGAN EARLY AND LATE
MONTH. GENERALLY 6 - 12 INCHES BURIED A NARROW PORTION OF THE SAGINAW
VALLEY ON THE
1ST-2ND,
WHILE 4 - 8 INCHES CLIPPED
THE EXTREME SOUTHEAST
CORNER OF LOWER MICHIGAN ON THE
25-26TH.
STRONG COLD BLASTS ROUTINELY
INVADED THE REGION, ERASING ANY ABOVE NORMAL TEMPERATURE DEPARTURES
THROUGHOUT MARCH AS SPRING WAS NOWHERE TO BE FOUND! IRONICALLY,
MARCH WAS THE ONLY "WINTER" MONTH THAT TEMPERATURES AVERAGED
BELOW NORMAL AND IN SOME WAYS, RESEMBLED WINTER MORE THAN
DECEMBER THROUGH FEBRUARY DID. IT IS ALSO INTERESTING THAT THE
MONTHLY AVERAGE TEMPERATURES OF DECEMBER THROUGH MARCH ALL
FELL TO WITHIN A FEW DEGREES OF EACH OTHER, WHICH IS SOMEWHAT
UNUSUAL IN ITSELF.
WINTER WAS NOT ONLY SLOW IN ARRIVING IN SOUTHEAST LOWER MICHIGAN,
IT WAS SLOW TO LEAVE AS SOME IMPRESSIVE COLD AIR BLASTS CONTINUED
TO INVADE THE AREA WELL INTO APRIL. NO MORE WAS THE TEMPERATURE
ROLLER-COASTER MORE APPARENT THAN IN MID APRIL. AFTER TEMPERATURES
SURGED TO RECORD HIGHS IN THE MID 80S MID MONTH (NOT TO MENTION
FLINT RECORDING THE WARMEST APRIL DAY ON RECORD/ 87-16TH), A STRONG
ARCTIC BLAST DROVE TEMPERATURES DOWN INTO THE 30S AND LOWER 40S
ON THE 21ST-22ND WITH RAIN MIXED WITH SNOW. NEARLY 1 1/2 INCHES /1.4/
OF SNOW FELL IN SAGINAW WHICH BROUGHT THE APRIL TOTAL (AS OF THE
25TH ANYWAY) TO 8.4 INCHES. ELSEWHERE, GENERALLY LESS THAN AN
INCH FELL OVER THAT COLD LATE APRIL WEEKEND.
SPECIFIC AREA TALLIES:
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DETROIT - FIFTH WARMEST WINTER ON RECORD
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AVE TEMP:
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33.8°F / +6.7°F
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SNOWFALL:
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33.7" / -7.5"
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WHILE DETROIT PLACED THE LOWEST OF THE THREE CITIES WITH THE 5TH
WARMEST WINTER, THIS STILL IS QUITE NOTABLE (IF NOT MORE SO) WHEN ONE
CONSIDERS IT WAS THE 5TH WARMEST WINTER IN 131 WINTERS (SINCE 1870-71).
SINCE DETROIT HAS THE LARGEST SAMPLE OF WINTER DATA, IT OFFERS THE BEST
PERSPECTIVE. THIS PAST WINTER PLACED JUST A TENTH OF A DEGREE BEHIND
THE MILD EL NIÑO WINTER OF 1997-98 (33.9/4TH). THEN, THERE IS
BETTER THAN
A DEGREE JUMP TO 3RD PLACE WITH 35.1 WHICH OCCURRED WAY BACK IN 1889-90,
WHILE SECOND PLACE WAS A HALF DEGREE WARMER WITH 35.6 DEGREES IN
1931-32. BY FAR THOUGH, THE MOST EXTRAORDINARY "WARM" WINTER WAS
WINTER OF 1881-82 WHICH NATURALLY OCCUPIES FIRST PLACE WITH AN
INCREDIBLE 37.0 DEGREE AVERAGE TEMPERATURE. THIS STANDS OUT AND IS
NEARLY A DEGREE AND A HALF ABOVE SECOND PLACE.
ALL FIVE TOP WARMEST WINTERS HAD LESS SNOWFALL THAN THIS PAST WINTER.
WHAT IS MORE SURPRISING IS THAT IF ONE BROADENS THE RESEARCH TO THE TOP
TEN WARMEST WINTERS (INCLUDING THE WINTER OF 2001-02), STILL NONE OF THE
SEASON SNOWFALLS AVAILABLE (8) HAD MORE SNOWFALL THAN THIS PAST
WINTER. ONE HAS TO LOOK DOWN TO THE 12TH WARMEST WINTER (AVE TEMP OF
31.2 IN 1920-21 AND A FULL 2.6 DEGREES COOLER THAT THIS PAST WINTER) TO
FIND MORE SNOWFALL, AND JUST BARELY WITH 36.1 INCHES. ALSO, LIKE MANY
OTHER WINTERS, DETROIT METRO AIRPORT HAD ONE OF THE LIGHTER SNOW
AMOUNTS ACROSS EXTREME SOUTHEAST LOWER MICHIGAN. SEVERAL OTHER
LOCATIONS REPORTED AT LEAST 3 FEET (HERE AT THE NWS WHITE LAKE WE
RECEIVED NEARLY 4 FEET /47.3/).
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FLINT - SECOND WARMEST WINTER ON RECORD
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AVE TEMP:
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31.7°F / +7.8°F
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SNOWFALL:
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40.4" / -4.7"
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SINCE 1942, FLINT'S AVERAGE TEMPERATURE OF 31.7 FOR THE WINTER RANKED
THE HIGHEST FOR WARMEST WINTERS OF THE THREE CITIES WITH SECOND PLACE.
THE ONLY WARMER WINTER OCCURRED DURING THE EL NIÑO WINTER OF
1982-83
WHEN THE AVERAGE TEMPERATURE WAS A HALF DEGREE WARMER AT 32.2. THE
WINTER OF 2001-02 WAS THE SECOND WARMEST WINTER SINCE THE WINTER OF
1942-43, OR 59 YEARS. THOUGH NOT OFFICIAL, EARLIER CO-OPERATIVE DATA
(SINCE 1893) DOES SUGGESTS THAT THIS WINTER WAS THE THIRD WARMEST SINCE
1893 WITH THE WINTER OF 1931-32 (DETROIT'S SECOND PLACE) IN FIRST PLACE.
WHEN LOOKING BACK AT FLINT'S WINTER DATA /1942+/, NONE OF THE FIVE TOP
WARMEST WINTERS (INCLUDING THIS WINTER) HAD MORE SNOW THAN THIS PAST
WINTER (SIX WINTERS IF 1931-32 IS USED). SINCE 1942, THE WINTER OF 1991-92
(IN 6TH PLACE WITH AN AVERAGE TEMP OF 28.2) DID CONTAIN MORE SNOWFALL
/54.4 INCHES/.
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SAGINAW - THIRD WARMEST WINTER ON RECORD
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AVE TEMP:
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30.6°F / +6.6°F
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SNOWFALL:
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55.8" / +9.8"
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THE WINTER OF 2001-02 NOW OCCUPIES THIRD PLACE FOR WARMEST WINTERS ON
RECORD IN SAGINAW SINCE 1900 WITH AN AVERAGE TEMPERATURE OF 30.6. THE
AFOREMENTIONED WINTER OF 1997-98 IS IN SECOND PLACE FOR WARMEST IN
SAGINAW WITH 31.0 DEGREES AND 1931-32 THE WARMEST WINTER (AND 2.2
DEGREES WARMER) WITH A 33.2.
ONE OF MOST IMPRESSIVE WINTER STATISTICS THIS PAST WINTER CAME OUT OF
SAGINAW. EVEN WITH AN AVERAGE WINTER TEMPERATURE OF OVER 6 1/2
DEGREES (6.6) ABOVE NORMAL, SNOWFALL FOR THE WINTER 2001-02 SURGED UP
OVER THE AVERAGE BY NEARLY 10 INCHES /9.8/ WITH A TOTAL OF 55.8 INCHES.
IN ADDITION, OVER HALF OF THAT TOTAL /29 INCHES/ FELL AFTER FEBRUARY
25TH! IT IS INTERESTING TO NOTE THAT THE SEASON TOTAL OF 55.8 MADE THE
20TH SPOT FOR SNOWIEST WINTERS (WHILE BEING THE THIRD WARMEST),
REPLACING THE 55.6 THAT FELL BACK IN 1977-76. WHEN REVIEWING THE TOP 20
WARMEST WINTERS IN SAGINAW, ONE CAN ELIMINATE ALL BUT ONE TO FIND A
WINTER WITH AS MUCH SNOW AS THIS PAST WINTER. THE WINTER OF 1908-09
/18TH WARMEST/ WITH A CONSIDERABLY LOWER AVERAGE TEMPERATURE (26.8
AS OPPOSED TO THIS WINTER'S 30.6) PILED UP 72.4 INCHES OF SNOW WHICH MADE
IT THE 5TH SNOWIEST ON RECORD.
THERE ARE SEVERAL POSSIBLE EXPLANATIONS AS TO WHY OUR WINTER WAS SO
RELATIVELY WARM. TO EXPLORE THESE REASONS, LET US REVIEW PORTIONS
OF THE WINTER 2001-02 OUTLOOK FOR SOUTHEAST LOWER MICHIGAN.
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NORTH ATLANTIC OSCILLATION-
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"Similar to last winter, and may be most important, will be the evolution
of the North Atlantic Oscillation (NAO). The NAO, basically, reflects the dominant
upper wind flow pattern over the North Atlantic. While in a negative phase,
the NAO sometimes tends to act as a block (or dam) to the upper wind flow
over the eastern half of North America. This blocking effect, in turn, tends
to deliver the polar/arctic air into the eastern half of the country and
Great Lakes more readily."
REVIEWING THE TREND OF THE NAO (
http://www.cdc.noaa.gov/~gtb/tele/nao.gif)
FOR THIS PAST WINTER SHOWS IT WAS A SIGNIFICANT CONTRIBUTING FACTOR
TO OUR UNSEASONABLE MILD WINTER. THROUGHOUT MUCH OF THE WINTER,
THE NAO WAS IN A NEUTRAL TO POSITIVE PHASE. THE NAO STARTED STRONGLY
POSITIVE IN EARLY DECEMBER, THEN REVERSED TO STRONGLY NEGATIVE BUT
ONLY FOR A FEW WEEKS (MID DECEMBER INTO EARLY JANUARY). AFTER, DURING
MUCH OF JANUARY AND FEBRUARY, THE NAO HELD IN THE NEUTRAL TO
POSITIVE PHASE WITH ONLY MINOR DIPS LATE JANUARY AND THEN AGAIN, LATE
FEBRUARY INTO EARLY MARCH. ANOTHER MORE NOTABLE NEGATIVE NAO
OCCURRED VERY EARLY SPRING IN MID MARCH AND AGAIN, IN EARLY APRIL AND THIS
IS WHEN THE LAST OF THE ARCTIC AIR PLUNGES WERE FELT ACROSS THE REGION.
IN FACT, THE NAO PATTERN IS REFLECTED FAIRLY WELL BY SOUTHEAST LOWER
MICHIGAN'S OVERALL TEMPERATURE PATTERN DURING THE WINTER. SINCE A
NEGATIVE NAO (NAO-) WAS SOMEWHAT OF A SCARCITY THIS PAST WINTER, SO
WERE THE PLUNGES OF ARCTIC AIR WITH MUCH OF THE REAL BITTER COLD AIR
REMAINING LOCKED UP IN CANADA WITH ONLY FLEETING BREAK-OUTS INTO
THE STATES, ESPECIALLY MID DECEMBER INTO EARLY JANUARY AND THEN
AGAIN, LATE IN THE SEASON
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EL NIÑO-
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"The same neutral pattern is expected to, more or less, remain in place
through much of the winter. Sometime late in the winter or spring, however,
a weak El Niño is expected to evolve. The timing of this El
Niño
evolution
will be one of the critical factors as to how this winter's weather will
play out It is interesting to note that the onset of El Niño, in
conjunction
with the NAO phase, had a fairly strong influence on our winter (and early
Spring) weather. Generally the milder Winters (1930-31, 1968-69, 1986-87,
1990-91) were a result of a overall neutral pattern where El Niño
began
early winter and/or the NAO phase was mainly positive. Generally, the
earlier (and/or stronger) El Niño was during the Winter, the milder
the
Winter outcome. This was especially true if the NAO (North Atlantic
Oscillation) was dominated by a positive phase."
AS THE CLIMATE PREDICTION CENTER EXPECTED, EL NIÑO DID INDEED BEGIN
TO SURFACE LATE IN THE WINTER AND WAS ACCOMPANIED BY THE
AFOREMENTIONED PREDOMINANT POSITIVE DOMINATED NAO. SINCE EL NIÑO
WAS JUST IN ITS INFANCY, HOWEVER, THE AFFECT ON SOUTHEAST LOWER
MICHIGAN WOULD HAVE BEEN MINIMAL. AS MENTIONED, THE STRENGTH AND
ENDURANCE OF THE POSITIVE PHASE OF THE NAO, HOWEVER, DID INDEED
SIGNIFICANTLY CONTRIBUTE TO THE WINTER'S EXCEPTIONALLY
MILD OUTCOME.
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UNEXPECTED SECOND PEAK IN SOLAR FLARE ACTIVITY-
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"Another consideration made when making the winter outlook is a check of
the solar activity during the years of the past winters studied. It is known
that sunspot activity has an impact on climatic trends and patterns over
the earth. The current sunspot cycle is then, compared with similar sunspot
cycles (timing/peak/intensity) of past winters studied. While this upcoming
winter sunspot maxima cycle will be on the wane, it will still be near the
peak reached the winter of 1999-2000."
AFTER THE SUNSPOT MAXIMUM OCCURRED EARLY IN 2000, IT WAS THOUGHT
THAT THE ACTIVITY WOULD GRADUALLY DIMINISH THROUGH THE WINTER OF
2001-02. HOWEVER, AN UNEXPECTED SECOND PEAK IN SUNSPOT ACTIVITY
OCCURRED EARLY THIS PAST WINTER. THAT SECOND PEAK WAS ACTUALLY VERY
CLOSE TO THE ORIGINAL PEAK BACK IN EARLY 2000. THERE IS SPECULATION
AMONG SOME SCIENTISTS THAT THE UNEXPECTED RESURGENCE IN THE SOLAR
ACTIVITY COULD HAVE BEEN AT LEAST PARTLY RESPONSIBLE FOR THE MILDER
WINTER. SOME SCIENTIST THEORIZE THAT THE SLIGHT INCREASE SOLAR ACTIVITY
MAY HAVE HELPED STRENGTHEN AND ALTER THE UPPER WIND PATTERN OVER
THE PACIFIC, WHICH MAY HAVE RESULTED IN MORE PERSISTENT TROUGHING
ALONG THE WEST COAST OF THE US. SUBSEQUENTLY, THIS WOULD TEND TO
PUSH MILD, PACIFIC AIR WELL INTO THE COUNTRY AND THUS, HELP KEEP
MUCH OF THE ARCTIC AIR AT BAY, BOTTLED UP IN CANADA.
CLOSER INSPECTION OF THE TWO RECENT SOLAR PEAK WINTERS (1999-2000 AND
2001-2002) DOES SHOW SOME TREND SIMILARITIES. REFLECTING BACK TO THE
WINTER OF 1999-2000, IT TOO WAS A LATE COMER WITH LIGHT AMOUNTS OF
SNOW FALLING THROUGHOUT. THE WARMEST OF THE WINTER CAME IN
DECEMBER AND THEN AGAIN IN FEBRUARY WITH EACH MONTH AVERAGING
ABOVE OR WELL ABOVE NORMAL AND, WITH ONLY 23.7 INCHES OF SNOW
FALLING IN DETROIT AND 29.5 IN FLINT..MADE THE TOP 20 SNOWLESS WINTERS
FOR BOTH CITIES. SAGINAW, HOWEVER, RECEIVED THE MOST WITH 47.2 INCHES.
THEREFORE, AND ALSO SIMILAR TO THIS PAST WINTER, THE STORM/SNOWFALL
PATTERN OF THE WINTER 1999-2000 SUGGESTS THAT THE DOMINANT STORM
TRACK ALSO RODE OVER SOUTHEAST LOWER MICHIGAN BUT A BIT FURTHER
NORTH THAN THIS PAST WINTER. UNLIKE THIS PAST MARCH, HOWEVER, MARCH
OF 2000 WAS CONSIDERABLY WARMER WITH LESS SNOW.
WINTER STUDY COMPARISONS (SEE TABLE-2) -
PERUSING THROUGH THE WINTERS IN THE ORIGINAL WINTER STUDY DOES REVEAL
SOME UNDERLYING COMMON THREADS TO THIS THE PAST WINTER. WHILE THE
WINTER OF 2001-02 ENDED UP TO BE WARMER THAN ANY IN THE STUDY, A FEW
DID RESEMBLE THE TEMPERATURE AND SNOWFALL TRENDS/TOTALS. THE
WINTERS OF 1930-31 AND 1990-91 WERE ALSO QUITE MILD AND CONTAINED
AROUND NORMAL TO BELOW NORMAL SNOWFALL. THE STRONGEST
CORRELATION IN THE STUDY COMES WITH 1930-31. CLIPPER STORM TRACKS
ACROSS THE NORTHERN STATES/SOUTHERN CANADA WERE DOMINANT
IN 1930-31 ALONG WITH A VERY ACTIVE TEXAS/ARKANSAS TO GREAT LAKES
STORM TRACK WHICH LED TO NORMAL TO ABOVE NORMAL SNOWFALL
ALSO, LIKE THIS PAST WINTER, MARCH WAS A BUSIER MONTH IN REGARDS TO
STORMS AND BROUGHT ABOVE NORMAL SNOWFALL TO SEVERAL AREAS. THE
DIFFERENCE THAT WINTER IS IT APPEARS THAT THE DOMINANT STORM TRACK
FROM TEXAS WAS JUST A BIT FURTHER SOUTH THAN THIS PAST WINTER. THUS,
DETROIT RECEIVED THE HEAVIEST SEASONAL SNOWFALL THE WINTER OF
1930-31 AS OPPOSED TO THE SAGINAW VALLEY THIS PAST WINTER. WHILE THE
WINTER OF 1990-91 WAS ALSO MILD, SNOWFALL AVERAGED BELOW NORMAL
AT ALL THREE LOCATIONS WITH THE STORM TRACK FURTHER NORTH THAN THE
WINTER OF 1930-31 AND 2001-02.
AS STATED IN THE WINTER OUTLOOK, THE VARIABILITY OF TEMPERATURES
AND EVEN MORE NOTABLY, THE WIDE RANGE OF SNOWFALL AMOUNTS WERE
EVIDENT. WHILE THE PROJECTED AVERAGE WINTER TEMPERATURE FROM THE
WINTERS IN THE STUDY WAS TOO COLD, THE EXPECTED OVERALL PATTERN OF
THE WINTER DID INDEED COME TO PASS FAIRLY WELL. THE IN-HOUSE STUDY
SUGGESTED THE WORST OF THE WINTER WOULD NOT COME AT ITS OPEN LIKE
LAST WINTER (2000-01), BUT IN MID TO LATE WINTER. IN OTHER WORDS,
THE DATA SUGGESTED THE WINTER OF 2001-02 WOULD LIKELY BE "BACK-END
LOADED". AFTER A RATHER NON-EVENTFUL WINTER THROUGH MUCH OF
JANUARY, THE STORM TRACK THAT BROUGHT US THE WINTER STORMS
BEGAN TO MATERIALIZE LATE JANUARY. BY LATE FEBRUARY, THE STORMS
INCREASED IN FREQUENCY AND IN SOME CASES, INTENSITY, INTO EARLY APRIL.
ALSO, THE STRONG PUSHES OF ARCTIC AIR NEARLY ABSENT THROUGH MUCH OF
THE WINTER, BEGAN TO PUSH SOUTH WITH AGGRESSION LATE FEBRUARY INTO
EARLY APRIL. IN FACT, THE RESEARCHED DATA GAVE THE STRONGEST SIGNAL
THAT MARCH (FIRST) AND JANUARY (SECOND) WOULD HAVE THE BEST CHANCE
OF HAVING ABOVE NORMAL SNOW. IN THE STUDY, 7 OUT OF 12 WINTERS
RECORDED ABOVE NORMAL SNOW IN MARCH, WHILE 6 OUT 12 HAD ABOVE THE
AVERAGE IN JANUARY. IN CONTRAST, DECEMBER HAD THE LEAST CHANCE WITH
ONLY 4 OUT OF 12 HAVING ABOVE AVERAGE SNOW (FEBRUARY WAS 5 OUT OF 12).
THIS PAST WINTER'S PATTERN OF A "BUSIER" OR STORMY MID-LATE WINTER WITH
THE MAJORITY OF THE SNOW FALLING THEN, MATCHED WELL WITH SEVERAL
WINTERS IN THE STUDY. THEY ARE: 1880-81, 1895-96, 1899-00, 1904-05,
1930-31, 1976-77, 1981-82 AND 1986-87. HOWEVER, WHILE THE WINTERS OF
1895-96 AND 1981-82 DID INDEED HAVE STORMY ENDINGS, THEY ALSO STARTED STORMY.
THE DOMINANT STORM TRACKS THIS PAST WINTER WERE WELL ADVERTISED IN
THE STUDIED WINTERS. THE DEVELOPMENT OF THE TEXAS/ARKANSAS LOW WAS
QUITE ACTIVE AND BROUGHT THE MOST NOTABLE SNOWS IN MID-LATE WINTER.
IN FACT, EVEN EARLY IN THE WINTER, THIS TRACK WAS NOTED (MAYBE A
BIT REFLECTIVE OF THE 1895-96 AND 1981-82?) BUT THE DOMINANT MILD PACIFIC
AIR AT THE TIME RESULTED IN MUCH OF THE PRECIPITATION BEING RAIN. WHILE
NUMEROUS CLIPPERS MOVED ACROSS THE NORTHERN US AND SOUTHERN CANADA,
MANY CONTAINED MODIFIED PACIFIC AIR EARLY TO MID WINTER. THE EFFECT OF
THE MODIFIED MILD PACIFIC AIR IS REFLECTED EXTREMELY WELL EARLY TO MID
WINTER NOT ONLY BY THE HIGH ABOVE NORMAL DEPARTURES, BUT BY THE SOMEWHAT
SMALL VARIANCES BETWEEN AVERAGE MONTHLY TEMPERATURES (BUT NOT NECESSARILY
INTRA-MONTH). THIS TREND OF SMALL VARIANCES IN MONTHLY AVERAGE TEMPERATURES
ALSO CONTINUED LATE WINTER INTO EARLY SPRING, BUT WAS DUE MORE TO IMPRESSIVE
TEMPERATURE SWINGS BALANCING OUT ONE ANOTHER WITH AN OVERALL PREFERENCE TO
COLDER THAN NORMAL TEMPERATURES.
TABLE-1: SHOWS THE MONTHLY TEMPERATURES/SNOWFALL AND DEPARTURES
FOR THE WINTER OF 2001-02. TEMPERATURE AVERAGES FOR THE
WINTER SEASON ARE DECEMBER THROUGH FEBRUARY...WHILE THE
SNOWFALL SEASON RUNS THE LENGTH OF OCCURRENCE.
___________________________________________________________________________
-AVE TEMP/DEPARTURE*- -SNOWFALL/DEPARTURE-
MTH DETROIT FLINT SAGINAW DETROIT FLINT SAGINAW**
----------------------------------------------------------------------------
OCT T/-0.2 T/-0.2 T/-
NOV 0.0/-2.9 T/-3.8 T/-
DEC 35.9/+7.6 34.1/+6.9 33.7/+7.5 4.9/-5.1 8.1/-1.5 9.0/-
JAN 32.7/+8.2 30.9/+9.6 29.1/+7.7 15.0/+4.5 15.6/+3.8 13.4/+
FEB 32.9/+5.7 30.0/+6.2 29.1/+5.3 6.7/-2.5 8.9/-1.0 10.1/N
MAR 7.1/+0.3 4.7/-2.8 14.9/+
APR T/-1.7 3.1/+0.4 8.4/+
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AVE: 33.8/+6.7 31.7/+7.8 30.6/+6.6 TOTAL: 33.7/-7.5 40.4/-4.7 55.8/+9.8
LAST WINTER (2000-01)
AVE 25.1/-0.5 22.9/-1.2 22.5/-0.7 39.0/-2.2 53.4/+8.3 67.8/+21.8
* NOTE THAT THE DECEMBER TEMPERATURE DEPARTURES ARE BASED ON THE
OLD NORMALS (1961-90), WHILE JANUARY - MARCH AND WINTER DEPARTURES
ARE BASED ON THE NEW NORMALS (1971-2000). WINTER 2000-01 DEPARTURES
ARE ALL BASED ON THE OLD NORMALS
** MONTHLY BREAKDOWN FOR AVERAGE SNOWFALL IS NOT AVAILABLE FOR
SAGINAW BUT WOULD BE SIMILAR TO FLINT. THEREFORE...
+ INDICATES ABOVE AVERAGE OR NORMAL
- INDICATES BELOW AVERAGE OR NORMAL
N INDICATES NORMAL
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TABLE-2
Winter Average Temperature Snowfall Year
Detroit Flint Saginaw Detroit Flint Saginaw
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1971-2000
30 year
Normals- 27.1 23.9 24.0 41.2 # 45.1 # 46.0 #
100 Year
Average- 26.5 - - - - -
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Winter-
1880-81 21.7 (14) - - 93.6 (1) - -
1895-96 26.7 26.0* - 54.3 (19) - -
1899-00 26.1 24.2* - 69.1 (4) - -
1904-05 21.4 (12) 18.4 (9)* 19.0(11) 37.4 - 58.1(16)
1930-31 30.3 -19- 28.3 -9-* 28.2-10- 47.8 45.8* 40.7
1962.63 20.3 (5) 17.0 (2) 15.7 (1) 28.1 39.5 34.8
1968-69 26.4 25.0 25.2 17.8 -8- 28.6 -8- 38.0
1976-77 19.8 (3) 16.9 (1) 18.3 (8) 43.9 44.8 -
1977-78 20.4 (7) 19.1 (5) 17.9 (6) 61.7 (8) 50.6 55.6 (20)
1981-82 21.8 (15) 20.9 (8) 20.3 (17) 74.0 (3) 62.2 (7) 43.4
1986-87 29.1 27.7 -10- 27.1 -15- 49.7 38.6 25.0 -13-
1990-91 29.6 26.7 -12- 25.7 31.4 34.2 -16- 25.4 -16-
Average
24.4 22.7 21.9 50.6 43.0** 40.1**
Winter
2001-02 33.8 -5- 31.7 -2- 30.6 -3- 33.7 40.4 55.8
( ) Coldest or Snowiest Ranking
- - Warmest or Snowless Ranking
*Not an Official Record ( Official Records Began in 1942 )
**Sample Incomplete and Therefore Not a reliable Snow Average
# Snow averages (1966-95)