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:

DETROIT - FIFTH WARMEST WINTER ON RECORD
AVE TEMP: 33.8°F / +6.7°F   SNOWFALL: 33.7" / -7.5"


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/).



FLINT - SECOND WARMEST WINTER ON RECORD
AVE TEMP: 31.7°F / +7.8°F   SNOWFALL: 40.4" / -4.7"


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/.



SAGINAW - THIRD WARMEST WINTER ON RECORD
AVE TEMP: 30.6°F / +6.6°F   SNOWFALL: 55.8" / +9.8"


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.

NORTH ATLANTIC OSCILLATION-
"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."
Graph of the North Atlantic Oscillation - Click to Enlarge 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

EL NIÑO-
"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.

UNEXPECTED SECOND PEAK IN SOLAR FLARE ACTIVITY-
"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.

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            -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/+

----------------------------------------------------------------------------
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
__________________________________________________________________________
1971-2000
30 year
Normals-   27.1       23.9       24.0          41.2 #     45.1 #      46.0 #
100 Year
Average-   26.5        -          -              -         -          -
__________________________________________________________________________
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) 


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