2/10/18

Update 2/10/18 - Bands of Moderate to Heavy Snow To Lay a Deep Snow Cover Over Portions of Southeast Lower Michigan into The Weekend



Update...
Here is the storm write-up and snowfalls and depths around SE Mich through Saturday 2/10; 7AM from the NWS and observers.

And below,  the RTP from this morning with addition snowfalls and depths....


RTPDTX
MORNING TEMPERATURE AND PRECIPITATION SUMMARY
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1157 AM EST Sat Feb 10 2018

Values represent yesterday`s highs/lows over the last 12 hours
and precipitation over the last 24 hours ending at 7 AM EST.


.BR DTX  0210  ES DH00/TAIRZX/DH07/TAIRZP/TA/PPDRZZ/SFDRZZ/SDIRZZ
:SOUTHEAST MICHIGAN -- TEMPERATURE AND PRECIPITATION STATIONS
:....................................................................
:       STATION              MAX / MIN  / 7 AM  / 24-HR / SNOW/ SNOW
:        NAME                TEMP/ TEMP / TEMP  / PRECIP/ FALL/ DEPTH
:....................................................................
WHKM4: NWS White Lake      :   20 /  15  /  16  / 0.37  /  5.1 / 12
ADG  : Adrian Airport      :   28 /  20  /  20  / 0.38
123M4: Ann Arbor           :   25 /  19  /  20  / 0.63  /  6.3 / 13
BAX  :*Bad Axe Airport     :   20 /  16  /  19  /
CFS  :*Caro Airport-Tuscola:   21 /  18  /  18  /
DET  : Detroit City Airport:   24 /  21  /  21  / 0.25
DTW  : Detroit Metro Airprt:   26 /  21  /  22  / 0.61  /  7.5 / 14
FNT  : Flint Bishop Airport:   21 /  14  /  18  / 0.32  /  6.5 / 13
ONZ  :*Grosse Ile Airport  :   28 /  22  /  22  /
OZW  :*Howell Airport      :   23 /  18  /  18  /
DUH  :*Lambertville Airport:   30 /  22  /  22  /
D95  :*Lapeer Dupont Airprt:   21 /  19  /  19  /
IKW  :*Midland Airport     :   21 /  16  /  18  /
TTF  :*Monroe Airport      :   29 /  22  /  22  /
RNP  :*Owosso Airport      :   21 /  18  /  19  /
PTK  : Pontiac Airport     :   22 /  18  /  20  /
P58  : Port Hope           :   23 /  19  /  20  / 0.07
PHN  :*Port Huron Airport  :   23 /  19  /  21  /
MBS  : Saginaw - Tri-Cities:   20 /  17  /  17  / 0.08  /  2.3 / 9
HYX  :*Saginaw-Harry Browne:   21 /  18  /  18  /
VLL  :*Oakland/Troy Airport:   24 /  21  /  22  /
YIP  : Ypsilanti Willow Run:   29 /  22  /  23  /
.END


*The temperature data for these sites above represent the highest and
 lowest temperatures that were reported on the METAR observations
 that transmit three times an hour and may not represent the actual
 high or low for that site. These sites do not measure precipitation.
.....................................................................


The following Cooperative Observer sites report from midnight to
midnight EST.


.BR DTX  0210  ES DH07/TAIRZX/TAIRZN/TA/PPDRZZ/SFDRZZ/SDIRZZ


:SOUTHEAST MICHIGAN -- TEMPERATURE AND PRECIPITATION STATIONS
:....................................................................
:       STATION               MAX / MIN  / MIDNITE/24-HR / SNOW/ SNOW
:        NAME                 TEMP/ TEMP / TEMP  /PRECIP/ FALL/ DEPTH
:....................................................................
MILM4: Milford- GM PRV GNDS:   22 /  13  /  17  / 0.50 /  5.0 / 9
MDLM4: Midland             :   20 /  11  /  17  / 0.16 /  3.5 / 7
MTCM4: Mt Clemens Selfridge:   24 /  14  /  21  / 0.47 /  7.5 / 12
SGNM4: Saginaw 5W          :    M /   M  /   M  / 0.29 /  3.6 / 8
.....................................................................


Cooperative observation values are for approximately 24 hours from
the previous OB time to the current Ob time.  Previous observation
times may not always be exactly the same.  The 24 hour low may be
from the previous morning.  Use the temperature at observation time
to help determine if the 24 hour low occurred this morning or the
previous morning.


.BR DTX  0210  ES DH07/TAIRZX/TAIRZN/TA/PPDRZZ/SFDRZZ/SDIRZZ




:..................................................................
:       STATION           OB   /MAX / MIN  /OB  /24-HR /SNOW/SNOW
:        NAME             TIME /TEMP/ TEMP /TEMP/PRECIP/FALL/DEPTH
:..................................................................
: ***BAY COUNTY***


  ***MIDLAND COUNTY***
OILM4:  Oil City          :0630/ 23 /  14 /  16 / 0.09/ 2.3/ 6


: ***HURON COUNTY***
BDAM4:  Bad Axe           :0706/ 20 /  14 /  18 / 0.12/ 1.4/ 8
FLNM4:  Filion 5NNW       :0630/ 20 /  13 /  17 / 0.07/ 2.1/ 8


: ***SAGINAW COUNTY***
CHSM4:  Chesaning         :0730/    /     /     / 0.11/   M/ 8
FKMM4:  Frankenmuth 1SE   :1000/ 21 /  15 /  17 / 0.10/ 1.7/ 8
MBSM4:  Saginaw 8NW       :0730/    /     /     / 0.11/ 2.3/ 9
SAGM4:  Saginaw           :0800/ 21 /  16 /  16 / 0.12/ 2.2/ 7


: ***TUSCOLA COUNTY***
CARM4:  Caro              :0915/ 20 /   M /  18 / 0.10/ 2.0/ 7
CSSM4:  Cass City         :0630/ 20 /  13 /  17 / 0.13/ 2.5/ M
VSSM4:  Vassar            :0700/ 22 /  14 /  17 / 0.08/ 2.0/ 8


: ***SANILAC COUNTY***
LEXM4:  Lexington         :0800/ 21 /  12 /  20 / 0.28/ 3.0/ 8


: ***SHIAWASSEE COUNTY***
CORM4:  Corunna 2NE       :0600/ 21 /  15 /  17 / 0.32/ 5.3/ 9
DRNM4:  Durand            :0800/ 22 /  16 /  17 / 0.24/ 5.7/ 10
OWSM4:  Owosso            :0700/ 22 /  16 /  18 / 0.24/ 3.5/ 9


: ***GENESEE COUNTY***
LIDM4:  Linden            :0800/ 22 /  15 /  17 / 0.30/ 2.0/ 6
GODM4:  Goodrich          :0730/ 23 /  15 /  18 / 0.25/ 4.9/ 10


: ***LAPEER COUNTY***
LPEM4:  Lapeer 2W         :1030/ 23 /  17 /  22 / 0.48/ 5.2/ 15


: ***ST. CLAIR COUNTY***
YALM4:  Yale              :0650/ 21 /  12 /  17 / 0.21/ 4.4/ 11


: ***LIVINGSTON COUNTY***


: ***OAKLAND COUNTY***
FARM4:  Farmington        :0730/ 22 /  15 /  19 / 0.40/ 5.2/ 9


: ***MACOMB COUNTY***
RICM4:  Richmond 4NNW     :0800/ 22 /  16 /  19 / 0.34/ 5.7/ 13


: ***WASHTENAW COUNTY***
AASM4: Ann-Arbor SE       :0730/ 26 /  16 /  20 / 0.53/ 5.8/ 12
CHLM4:  Chelsea           :0930/ 25 /  18 /  19 / 0.38/ 4.0/ 9
MCHM4:  Manchester        :0945/ 26 /   M /  20 / 0.62/ 6.5/ 11
SLNM4:  Saline 4SW        :0800/ 27 /  17 /  21 / 0.55/ 7.0/ 13
SALM4:  Saline            :0715/ 28 /  15 /  21 / 0.60/10.0/ 15


: ***WAYNE COUNTY***
DBNM4:  Dearborn  #2      :0500/ 26 /  16 /  22 / 0.58/ 7.8/ 10
GPFM4:  Grosse Pte Farms  :0800/ 23 /  15 /  20 / 0.60/ 6.0/ 14
WYTM4:  Wyandotte         :0800/    /     /     / 0.58/ 7.1/ 14


: ***LENAWEE COUNTY***
MRIM4:  Morenci           :0730/ 31 /  15 /  18 / 0.29/ 3.3/ 8
TECM4:  Tecumseh          :0800/ 28 /  14 /  22 / 0.55/ 7.8/ 14
TIPM4:  Tipton 2WNW       :1045/ 29 /  15 /  19 / 0.55/   M/ 12


: ***MONROE COUNTY***
DNDM4:  Dundee            :0635/ 27 /  17 /  20 / 0.40/ 5.0/ 10
.END


*All data above is preliminary and has not undergone final quality
control by the National Climatic Data Center /NCDC/. Therefore...this
data is subject to revision. Final and certified climate data can be
accessed at www.ncdc.noaa.gov.


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Thursday afternoon - Feb 8th 2017
 
A classic "old-fashion" strong overrunning weather event which is more robust than usual will lie over the Southern Great Lakes into the weekend. Much of the snow is expected to fall  overnight into Friday. In more technical terms the FGEN, moisture (and associated convergence) and baroclinic zone are all is very notable with the system. The forcing and strong vertical velocities through the 700 MB along with moisture and associated temperatures aloft all create the dendrite growth for snow. 

Since this is a strong overrunning /FGEN/ event it has its own set of problems forecasting. An impressive upper jet 120kts - 140kts creates a right entrance region over the west-east front which will lie over extreme northern Illinois, Indiana and Ohio. This will aid in creating bands of moderate to heavy snow over areas just north of the front. Where the snow is to fall is coming together with the models placing best snows over the southern half of Southeast Lower Michigan: basically from I-69 south to the Ohio Border. Within that area; the band of heaviest snow is shown below, depending on model. To me after looking at the models and previous events; this seems the most realistic projection path of the snow event through Saturday Forenoon. The placement and snow amounts reflects the atmospheric potential at this time. Amounts are likely to be  1-2" below/above to totals depicted at the specific time.

These maps are from the NAM and reflect the more liberal Kuchera amounts which takes into account the colder air mass. The latest 18z/1PM, Thu/ NAM projects approximate amounts into Fri afternoon. Since it's been my experience, the Kuchera snow method tends to be on the higher side (but not always with colder air in place); I added the 1"-2" below/above range to the map snow depictions. 


Looking at the earlier 12Z NAM run through Sat Forenoon Projects the heavier snow-band amounts across the southern half Southeast Lower Michigan. Again; look for amounts to range 1-2" from totals depicted at the specific time. The heaviest core is across the Ann Arbor- Detroit Metro area south to the Ohio border. This area must be watched for changes in location or/and amounts but heaviest snows could theoretically build to around a foot or more by Sunday as more snow sets up in this corridor at times through the weekend.


 Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian


2/4/18

Flaky Winter Thus Far - And I Don't Mean Just The Snowfall - And What About the Rest of the Winter?


Well Punxsutawney Phil brought two messages this Ground Hog Day. First; there will be six more weeks of winter (he must be looking at my Outlook). Second; with the ups and downs in the temperature department this winter, he doesn’t know whether to come out for the spring or scurry back into his warm hut before freezing to death and thus:



Certainly the most notable trend seen (and felt) this Winter of 2017-18 thus far, have been some impressive, but thankfully intermittent Arctic cold outbreaks. The worst of the cold arrived in time for Christmas; accompanied by a snowstorm with the cold persisting right into the the first week of the New Year.

This winter's snowfall across Southeast Lower Michigan hasn't been absent but the associated pattern of storms that produced much of it have been rather mediocre and infrequent, especially in January. There have been almost predominantly clipper-type systems this winter with the moisture rich Gulf helping to create Texas/Arkansas Lows being mainly absent. 

Over Southeast Lower Michigan; areas around and south of I-69 to the Ohio border have received normal to above normal snowfall with the heaviest core extending from the I-69 corridor including Flint, south into the far north and northwest suburbs of Detroit. Strangely enough, areas just a bit further north across the Saginaw Valley have only seen about half the norm.  Earlier projections of above normal snows for the Saginaw Valley doesn't look likely unless that region receives a some good snowfalls into spring.

Best snows fell in December thus far with two notable storms - the 13th and Christmas Eve into Christmas Day. While creating a picturesque Christmas, the resultant snow also created horrible driving conditions for holiday travelers. Finally; even with some rain storms during January thaws, overall precipitation remains clearly below normal across the entire land. 

On the whole, temperature have averaged below normal but that certainly doesn't even begin to reflect the roller-coaster ride they've been on to get there. Want proof ? Just take a drive on many of the local paved roads - the assortment of old and newly eroded crop of potholes will attest to it. This has been an extraordinary pot-hole creating winter with its frequent deep freezes and notable thaws. Just looking at the Local Climatic Data /F6/ from Detroit thus far, displays the up/down roller-coaster pattern well. Days with above normal temperature departures are depicted/shaded in red, while below are in blue. Obviously, up/down departures happen daily but the persistence and magnitude (especially below normal) is what catches ones eye.


PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6)

                                          STATION:   DETROIT MI
                                          MONTH:     DECEMBER
                                          YEAR:      2017
                                          LATITUDE:   42 13 N
                                          LONGITUDE:  83 20 W

  TEMPERATURE IN F:       :PCPN:    SNOW:  WIND      :SUNSHINE: SKY     :PK WND
================================================================================
1   2   3   4   5  6A  6B    7    8   9   10  11  12  13   14  15   16   17  18
                                     12Z  AVG MX 2MIN
DY MAX MIN AVG DEP HDD CDD  WTR  SNW DPTH SPD SPD DIR MIN PSBL S-S WX    SPD DR
================================================================================

 1  49  31  40   5  25   0 0.00  0.0    0  3.3 12 250   M    M   5        13 250
 2  50  31  41   6  24   0 0.00  0.0    0  4.2 14 200   M    M   9 1      16 190
 3  55  30  43   9  22   0 0.00  0.0    0  4.5  9 170   M    M   4 18     13 250
 4  56  36  46  12  19   0 0.02  0.0    0 12.5 26 190   M    M  10        33 180
 5  58  30  44  10  21   0 0.02    T    0 23.4 32 240   M    M   9        45 210
 6  41  27  34   1  31   0 0.00  0.0    0 18.5 32 230   M    M   4        40 270
 7  32  25  29  -4  36   0 0.02  0.6    T 12.6 21 240   M    M  10 8      27 250
 8  33  19  26  -6  39   0    T    T    T 13.9 25 210   M    M   4        30 210
 9  30  24  27  -5  38   0 0.10  1.5    T  9.0 18 200   M    M  10 8      23 200
10  30  24  27  -5  38   0    T    T    1 12.3 23 220   M    M   9        27 220
11  31  24  28  -3  37   0 0.27  3.8    4  5.0 14 310   M    M  10 18     20 310
12  32  16  24  -7  41   0 0.01  0.2    4 14.9 29 310   M    M   8 169    36 330
13  26  14  20 -11  45   0 0.42  6.3    4  9.6 21  10   M    M  10 129    27  10
14  21  10  16 -14  49   0 0.01  0.2    9  8.4 16 360   M    M   6 89     19 350
15  28  16  22  -8  43   0 0.01  0.3    7 11.8 24 220   M    M  10        29 240
16  36  21  29  -1  36   0 0.02  0.7    7  9.3 17 220   M    M  10 8      23 220
17  36  21  29   0  36   0 0.00  0.0    6  6.0 12  70   M    M   9 18     15  70
18  41  30  36   7  29   0 0.01  0.0    5 12.5 20 230   M    M  10 18     23 240
19  48  37  43  14  22   0 0.00  0.0    T 15.1 23 240   M    M   6        28 230
20  38  28  33   4  32   0 0.00  0.0    T  6.5 22 300   M    M   5        29 310
21  35  28  32   4  33   0    T  0.0    0  7.5 16  70   M    M  10        22  60
22  36  33  35   7  30   0    T  0.0    0  5.3 15  70   M    M  10 18     20  70
23  37  28  33   5  32   0 0.07  0.7    0  7.9 17 310   M    M   8 1      23 300
24  28  20  24  -4  41   0 0.34  4.4    1  8.0 17 290   M    M  10 1      20 290
25  22  11  17 -11  48   0 0.03  1.0    5 15.8 29 250   M    M   8 189    36 260
26  14   3   9 -18  56   0 0.02  0.7    6  8.1 18 250   M    M   9 19     22 250
27  13  -4   5 -22  60   0 0.00  0.0    5  7.0 16 320   M    M   3 18     19 280
28  14  -3   6 -21  59   0 0.04  1.2    5  3.7  9 170   M    M   7 18     11 170
29  19  10  15 -12  50   0 0.05  0.6    6  9.2 17 250   M    M   9 18     20 230
30  17   4  11 -16  54   0 0.02  0.3    6 11.3 22 290   M    M   7 18     31 280
31  17   2  10 -16  55   0 0.00  0.0    6  5.0 10 300   M    M   6        13 330
================================================================================
SM 1023  626      1181   0  1.48    22.5 302.1          M      245
================================================================================
AV 33.0 20.2                               9.7 FASTEST   M    M   8    MAX(MPH)
                                 MISC ---->  # 32 240               # 45  210
================================================================================
PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6)

                                          STATION:   DETROIT MI
                                          MONTH:     JANUARY
                                          YEAR:      2018
                                          LATITUDE:   42 13 N
                                          LONGITUDE:  83 20 W

  TEMPERATURE IN F:       :PCPN:    SNOW:  WIND      :SUNSHINE: SKY     :PK WND
================================================================================
1   2   3   4   5  6A  6B    7    8   9   10  11  12  13   14  15   16   17  18
                                     12Z  AVG MX 2MIN
DY MAX MIN AVG DEP HDD CDD  WTR  SNW DPTH SPD SPD DIR MIN PSBL S-S WX    SPD DR
================================================================================

 1  13  -2   6 -20  59   0    T    T    6  9.2 24 290   M    M   9 18     32 280
 2  13   0   7 -19  58   0    T    T    6 15.3 22 210   M    M   8        26 220
 3  17   0   9 -17  56   0 0.01  0.5    6 13.4 21 220   M    M  10 1      26 220
 4  17   1   9 -17  56   0    T    T    6 10.9 21 300   M    M   6 8      26 330
 5   6  -4   1 -25  64   0 0.00  0.0    6 10.8 23 300   M    M   1 8      29 330
 6  10  -5   3 -23  62   0 0.00  0.0    6  5.5 15 320   M    M   2        20 330
 7  30  -6  12 -14  53   0 0.01  0.2    6 12.3 24 210   M    M   9        31 210
 8  37  29  33   7  32   0 0.24  2.2    8 14.7 22 230   M    M   7 149    28 250
 9  37  25  31   5  34   0 0.00  0.0    6  6.6 13 170   M    M   6 18     16 250
10  46  25  36  10  29   0 0.08    T    6  6.9 16 180   M    M   9 16     19 180
11  57  43  50  24  15   0 0.02  0.0    2 14.6 22 170   M    M  10 1      27 170
12  55  14  35  10  30   0 0.19  0.7    0 17.1 28 360   M    M  10 146    38 360
13  19  11  15 -10  50   0    T    T    1 10.1 26 340   M    M   7        35 330
14  20   8  14 -11  51   0    T    T    1  5.8 17 200   M    M   8        20 160
15  22  15  19  -6  46   0 0.06  1.9    T  7.3 15 140   M    M  10 1      19 130
16  22   7  15 -10  50   0    T  0.2    2 11.1 16 230   M    M  10 18     18 230
17  24   2  13 -12  52   0    T  0.1    2 11.9 24 220   M    M   7 18     31 230
18  28  13  21  -4  44   0 0.00  0.0    2 16.4 21 230   M    M   5        29 230
19  36  21  29   4  36   0 0.00  0.0    1 17.2 29 220   M    M   4        36 220
20  43  31  37  12  28   0 0.00  0.0    1 12.6 24 230   M    M   7        34 230
21  42  33  38  13  27   0    T  0.0    T  2.8 12 180   M    M  10 12     14 170
22  55  38  47  22  18   0 0.40  0.0    0  7.2 22 190   M    M  10 12     26 190
23  47  29  38  13  27   0 0.12  0.0    0 16.2 29 210   M    M  10 13     36 240
24  30  25  28   3  37   0    T    T    0  6.5 17 310   M    M  10 8      22 310
25  35  25  30   5  35   0    T  0.0    0  6.7 16 200   M    M   8 1      19 200
26  53  27  40  15  25   0 0.00  0.0    0 11.6 26 200   M    M   4        32 200
27  50  31  41  16  24   0    T  0.0    0 17.4 30 210   M    M   8        39 220
28  47  27  37  11  28   0 0.00  0.0    0  5.6 17  60   M    M   4        23  50
29  31  18  25  -1  40   0 0.23  3.4    T 12.3 22 360   M    M  10 12     27  10
30  23  13  18  -8  47   0    T    T    3  8.5 15 280   M    M   9         M  M
31  41  22  32   6  33   0 0.00  0.0    3 15.4 31 220   M    M  10        37 220
================================================================================
SM 1006  516      1246   0  1.36     9.2 339.9          M      238
================================================================================
AV 32.5 16.7                              11.0 FASTEST   M    M   8    MAX(MPH)
                                 MISC ---->  # 31 220               # 39  220
==============================================================================

Looking at the analogues the past few months and their predominant temperature and snowfall prognostications below; served us very well thus far this winter. I already blogged about December's actual and projected numbers and performance, therefore let's check January to give an idea how I check performance.

Looking at the top temperature chart (below) we see basically January's actual temperature average mirrored the analogues projections. First off, January's analogue temperature projections were more mixed and evenly divided though; still had a slight biased to colder than average /-1.1/. This was less of a departure than Decembers predominately below normal projections and results. December's prevailing colder than normal numbers and the average is depicted in blue on this chart. On it's performance, I used the below normal average added to the general average of all the 14 Decembers and divided by two to be fairer in using all the set of analogues. This therefore, gives the weighting to the strongest forecast indicators but still accounts for all the data in the analogue temperature forecast.

Since January's set of analogues contained seven below and seven above; I use the usual mean of all those numbers as a comparison number since neither was dominant. The average of all the January analogues came in at 24.5, or -1.1 below the January norm average of  25.6. Outstandingly, this January's average came in nearly identical to that projected number - 24.6!  You will fine the average for all the January temperature years and the January 2018 actual temperature (the white number at the bottom) in the January column.


DETROITTEMPS
P
SEASONDECJANFEBWNT AVEWINTERAO / SCSEASON
1890-9127.328.830.628.91AO+/SC++1890-91
1893-9427.729.923.627.11AO-/SC--1893-94
1898-9926.924.019.823.61.AO-/SC++1898-99
1910-1123.327.428.826.52AOn/SC++1910-11
1917-1821.913.224.519.93AO-/SC--1917-18
1950-5125.427.827.727.02AO-/SC+-1950-51
1955-5627.326.428.127.33AO-/SC--1955-56
1971-7233.323.824.627.24AOn/SC+-1971-72
1975-7629.119.233.327.25AO+/SC++1975-76
1984-8534.02323.4274AO-/SC++1984-85


1999-20
32.024.631.929.52AO+/SC--
1999-20
2000-0119.326.226.724.15AO+/SC--2000-01
2008-0927.417.328.524.46AOn/SC++2008-09
2011-1235.530.732.632.93AO+/SC--2011-12
Ave25.624.527.426.6
26.5Ave
NORM 30Y30.125.628.127.9100YR -26.7Norm
Dep-4.5-1.1-0.7-1.3
-0.2Dep
2017-1826.624.6





DETROITSNOWFAL
SEASONOCTNOVDECJANFEBMARAPR
1890-91T2.511.91.5


27.0
1893-94T2.716.61.4


45.5
1898-99T8.916.04.2


60.2
1910-11T2.320.15.8


50.2
1917-18T0.99.218.6


38.4
1950-510.09.26.515.4


42.2
1955-56T4.84.811.0


45.2
1971-720.04.22.67.9


29.0
1975-7606.519.815.1


55.9
1984-850.04.16.220.9


55.1
1999-200.0T4.39.6


23.7
2000-01T1.325.13.4


39.0
2008-0902.221.425.2


65.7
2011-1200.65.79.3


26.0
AveT3.912.210.7



30y Norm0.11.49.712.5



Dep-0.12.52.5-1.8



2017-18

22.59.29.27


ColorTempsDegrees
RainInches
Snow
Legend:Below1.0>
Below1.00>
Below

Normal0.0-1.0
Normal0.00-1.00
Normal

Above1.0>
Above1.00>
Above










January’s actual snowfall (above) for Detroit /9.2"/ was 1 1/2" below the mean average of all the analogues at 10.7" (and also below the norm of 12.5"). Since snowfall amounts have such a wide potential outcome down to the tenths, I’m more concerned with the trend found rather than the actual number above or below. I check the performance by first waiting for the actual number for the month and then, compare its respective category (above, below, normal) it falls into from the analogue s set. I consider the predominant trend found -in this case below normal- and lean more heavily on that and less at the actual number. If we add all the predominant below normal January snows and divide by the number of below (nine) we get 6.0”; lower than the actual number of 9.2” and quite a bit lower than the actual norm of 12.5”. Therefore; snow or rainfall projections in the analogues are handled mainly as prevailing trends and secondary to the actual number.

Outlook

Well, why this is fine and dandy for the past - what about the future, the rest of the winter into mid spring? On the surface it looks as though analogues, models and even the ground hog all agree on six more weeks winter into mid March anyway.

A quick glance at the analogues pretty much continues the trend with a slight edge /-0.7/ to normal to below normal temperatures (albeit via roller-coaster) through February. Then; a more mixed opinion for March (warmer with nine above) and April (colder with nine below). March's data is extraordinarily wide ranging and speaks volumes for what March is known for: wild with big temperature gyrations! Analogue March temperature ranges(*) from 29.3 to 50.7! Anyone recall that March of 2012 with that exceptionally warm average of 50.7? The transition seasons as I call them (Spring, Autumn) generally a more difficult to peg because of timing issues between Winter and Summer and also associated big temperature fluctuations.

In my original Winter Outlook; I went with a decidedly colder trend for the overall winter with temperatures averaging normal to below (up to 3.0 degrees below). Thus far through January; Detroit is averaging close to 2 1/2 degrees below normal.

Snowfall and rainfall continue the below normal trend (Detroit area) for February in the analogues but with a pick up somewhat in March and April. As noted however; snowfalls for the entire season across Southeast Lower Michigan came in around normal (within 5" of the norm - 43.4") from the metro Detroit area south to Ohio - and above normal from the north/northwest suburbs into Flint and Port Huron. Earlier projections of above normal snows for the Saginaw Valley doesn't look likely unless that region receives a some good snowfalls.

 It must be noted however; though the trend is for below normal snows in the analogues in February for the Detroit area there were some hefty snows as outliers in both February and March. In addition, this season looks to have the appearance of a snowier beginning with a snowier end - occasionally seen with the front/back end loaded winters /U shaped/. The later part of the winter into early spring is notorious for that as more moisture returns to the region from the south. As with all projections besides trends, timing issues can cause problems with overall cold/wet or warm/dry trends overlapping months.

_____       Analogues into Spring 


FEBMARAPR
1890-9130.630.848.3
1893-9423.640.447.6
1898-9919.829.3*45.4
1910-1128.833.750.5
1917-1824.539.644.6
1950-5127.736.546.0
1955-5628.132.445.7
1971-7224.632.644.6
1975-7633.340.450.0
1984-8523.438.451.0
1999-200031.944.048.0
2000-0126.735.151.2
2008-0928.538.749.8
2011-1232.650.7*49.4
AVE27.436.948.0
NORM28.137.249.2
DEP-0.7-0.3-1.2










































































FEBMARAPRSEA TOT
2.67.90.627.0
14.64.26.045.5
6.524.10.560.2
13.37.51.250.2
4.84.30.638.4
4.46.50.242.2
10.613.30.745.2
9.32.52.529.0
4.97.52.155.9
16.96.10.955.1
8.11.10.623.7
2.95.40.939.0
8.51.07.465.7
10.20.2T26.0
8.46.54.043.4
10.46.91.742.3
-1.4-0.10.10.7
7





_______Computer projections for the remainder of winter into spring.


Note the resilient prevailing blocking pattern set up for February. Impressive troughing appears to be reloading over eastern Canada and occasionally pushing well south into the eastern US. 







____________CFS Model Projections 

Current CFS model projects a colder and drier February (total precipitation, not necessarily snowfall).




March (below) holds on to normal to below for temperatures while precipitation is normal to above. The last two maps reflect the three month temperature period and prevailing upper air pattern. The huge trough over eastern Canada meanders further east with time.





 Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian