4/8/13

"January through March"; The Real Winter of 2012-13

Without a doubt, the Winter of 2012-13 was late in getting started and even statistically,  better suited the months of January through March rather than the standard climate months of December through February. In fact, March's average temperatures at all three climatological sites ended up colder than December's temperatures, something not seen often. Normals for Southeast Lower Michigan in December average in the upper 20s to around 30; while normals for March average in the mid 30s. Last December saw temperatures average in the mid 30s across the entire region (DTW - 35.9; FNT - 33.5; MBS - 34.1 for a Southeast Lower Michigan average of 34.5) which as you can see, match March's normals of mid 30s well.

In the reverse, this past March of 2013 saw temperatures average in the lower to mid 30s (DTW - 34.6; FNT - 32.2; MBS - 31.3 for an average of 32.7) nearly two degrees below December 2012's average temperature for Southeast Lower Michigan of 34.5! Not quite as cold as December's normal temperatures but still represented December better than December's 2012 actual temperatures did.

While normally March gradually warms up as the month unfolds, this really didn't happen until the last six days of the month when readings averaged normal to above. Two thirds of the month average below normal with the largest departures ironically coming when spring was to commence; the 20th and 21st with temperatures averaging 13.5 degrees below normal.  On the flip side to this cold, just two exceptionally mild days stole about a degree below monthly departure (in other words; the departure for the month would have been 3.0 - 3.5 degrees below normal, rather than 2.0 - 2.5 below). A storm center that pushed north of the region on the 10th/11th and pulled unseasonably mild air into the area with temperatures rising into the mid 50s to mid 60s...averaging 14 degrees above normal.

While snowfall around the region is still possible; chances diminish quite notably from early April to late April. And; despite the mild winter, snowfalls up through the first week of April actually performed admirably. Detroit has recorded 47.6" exactly 6.0" /norm- 41.6" thus far/ above normal and right on the normal-above normal threshold used in analogues. Normal snowfall for the entire season at Detroit; 42.7". Snowfall at Flint was a few inches below the normal thus far with 43.6" recorded, normal for the entire season stands at 47.4" and thus, -3.8" thus far.  Saginaw recorded 43.4" (just .2" different from Flint) and season normal stands at 46.1".

CLIMATOLOGICAL WINTER 2012-2013 (DEC, JAN, FEB) STATS/RANKINGS - NWS
 
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PRECIPITATION

              ACTUAL   NORMAL  DEPARTURE     RANKING
DETROIT AREA   8.92"    6.44"   +2.48"     11TH WETTEST
FLINT AREA     8.04"    5.03"   +3.01"      6TH WETTEST
SAGINAW        7.14"    5.24"   +1.90"     16TH WETTEST


AVERAGE TEMPERATURE

              ACTUAL   NORMAL  DEPARTURE     RANKING
DETROIT AREA   30.4     27.9     +2.5      17TH WARMEST
FLINT AREA     28.5     24.9     +3.6      10TH WARMEST
SAGINAW        28.5     24.7     +3.8      10TH WARMEST


AVERAGE HIGH TEMPERATURE! 
              ACTUAL   NORMAL  DEPARTURE     RANKING
DETROIT AREA   37.5     34.4     +3.1    T-16TH WARMEST
FLINT AREA     36.2     32.2     +4.0     T-8TH WARMEST
SAGINAW        35.2     31.4     +3.8          N/A*


AVERAGE LOW TEMPERATURE

              ACTUAL   NORMAL  DEPARTURE     RANKING
DETROIT AREA   24.0     21.4     +2.6      21ST WARMEST
FLINT AREA     20.9     17.7     +3.2      14TH WARMEST
SAGINAW        21.7     18.0     +3.7          N/A*


DETROIT AREA HAS A CLIMATE RECORD DATING TO NOVEMBER 1874
FLINT AREA HAS A CLIMATE RECORD DATING TO JANUARY 1921
SAGINAW HAS A CLIMATE RECORD DATING TO JANUARY 1912

*RANKINGS OUTSIDE THE TOP 20 FOR SAGINAW ARE CURRENTLY UNAVAILABLE
DUE TO ONGOING UPDATES FOR THE SAGINAW AREA DATABASE
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Next up on the Winter of 2012-13; I'll take a look at the analogue 
performance and what analogue(s) performed the best in relevance to
this winter and associated spring projections.
 
Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian
 
  

2 comments:

  1. Excellent Write-Up :). Great Discussion of an unusual climatic situation. Very well written and relatable :).

    ReplyDelete