4/10/18

What's That; You Think That Our Recent Cold and Snowfalls Over Southeast Michigan are Bad?


Mom Nature certainly has been taking her sweet ole' time "blooming" across the Great Lakes and Southeast Lower Michigan this year. What, with the rather persistent cold leading to well below normal temperatures in April /10-12 degree ave below as of April 10th/ and occasional snowfalls, our weather has been more typical of a winter month. The good news is a warm-up to normal then, even above normal temperatures should round out the week; the bad news the cold snaps aren't done - nor the snow. Latest data intimates after a break; more cold and possibly snow or snow showers will reappear by early next week. So gardeners and outdoor enthusiasts, you might want to take advantage of the warmer weather -alas between rains - and make the most of it. In addition, it's advisable to keep those plants safe inside for the time being. Typically, mid April brings high temperatures in the mid 50 to near 60 with lows dropping into the 30s. 

April 6th seems to be a bit of an ominous day in April for snows and cold; as evidenced by this past April 6th when 1 - 3" of snow fell and the following...

This is an account of Detroit's biggest snowstorm ever recorded since records began in 1870. There are no records and Flint nor Saginaw back in 1886.  I wrote the original article back in 2000 with an update later which included maps. In more modern weather history, another storm I recalled and just researched not only dumped around 7" of snow at Detroit and Flint /4" at Saginaw/ but also drew down record cold behind it April 6-8th, 1982. This cold snap blew away any record lows previously set on those dates for over a hundred years and most remain intact into 2018. Flint had it's coldest day ever on record for April 7th with a low of 6 degrees!


            April 6 1886 Super Snowstorm (weather maps now included)

    Written by: William R. Deedler, Weather Historian

While the Snowstorm of April 6th 1886 had been written about in the past,  I am now able to include the weather maps drafted at that time, so long ago. At the time I wrote about the storm (along with the storm of December 1st, 1974), I had to estimate the weather map just by local surface observations available from Detroit. I wrote about some similarities between the two storms (1886 & 1974). And now, looking back at the roughly drawn weather maps from 1886, you could also toss in our big blizzard of January 26th, 1978 for good measure. All three storms involved some sort of strong, deep upper low pressure system /500 MB Low/ over the Upper Ohio Valley, most like negatively tilted (which would help explain the backing of the storm to the north-northwest and it’s ability to draw Atlantic, along with Gulf, moisture north and westward into the Great Lakes). Obviously, there was no upper air data way back in 1886 but just by looking at the evolution of this massive and late season snowstorm, an estimate of the upper level system could be drawn (along with fine tuning the available surface maps) from April 4-6th, 1886 7AM EST surface analysis.

APRIL 1886 SCENARIO

By early April 1886, some residents of Southeast Lower Michigan had most likely started on spring outdoor activities. High temperatures frequently pushed well into the 50s from mid March on; the last hint of snow fell nearly two weeks before on the 23rd. No doubt the growing season's new green vegetation was well underway.
 
The weather days proceeding the massive and incredible snowstorm hinted little of what was yet to come; however, there were some subtle signs of trouble brewing. The first was a fresh, brisk northeast wind that blew continuously for nearly three days prior to 6th (generally, an easterly wind along with a falling barometer in this region, foretells of foul weather approaching the area). On the 4th into the 5th, observations including temperatures, wind flow and pressure changes indicated an unseasonably cold high pressure system pushing slowly into Southern Canada and the Northern Great Lakes. This persistent and strengthening northeast wind along with an extended period of steady, then slowly falling barometric pressure, during the three-day period (3rd, 4th and 5th), indicates this high was a fairly strong, resilient and a blocking type of high pressure. A second and more foreboding sign of what was to come was indeed a rapidly falling barometric pressure later on the 5th, which foretold of the major storm approaching Southeast Lower Michigan. The surface observations late on the 5th indicated a low pressure and storm center approaching the Southern Great Lakes from the south or southwest (most likely from Illinois, Indiana or Ohio) as the cold high to the north slowly retreated.
 
The afternoon high on the 5th reached only 38 degrees (about 15 degrees below normal) and then held nearly steady into the evening. Increasing high cirrostratus clouds mingled with the sunset but then, quickly lowered to altostratus and nimbostratus as midnight approached. Light snow began to fly just after midnight and remained light until becoming heavy during the predawn hours. Note the following taken from the actual Detroit Weather Log dated April 6th, 1886:
"Snow began at 12:30 AM and fell light until about 4:30 AM when it began to fall heavy and a tremendous fall of snow continued all day, ending at 9:00 PM. The fall at 7:00 AM was 4.6" and at 3:00 PM was 17.1" and at 11:00 PM, 2.4" making the total of 24.1 inches melted from the snow gauge. The rain gauge was soon snowed full and was practically useless. Total fall of the snow on the level was 24.5 inches. The snow was badly drifted by the heavy gale. The drifts in some places were 12 feet high and the snow in the street was from 10" to 40" inches deep. A heavy north gale set in at 1:45 AM and raged in fury all day reaching 40 miles north at 2:15 PM and continued all the remainder of the day. Its force with the snow was appalling. It blew the snow in fine particles against the face, cutting like a knife."
The synopsis continues with a description of numerous street cars that were abandoned, strewn about and laying in all sorts of positions. As one might expect with the snow falling in April, the snow contained a high water content (2.43") and, therefore, it was very heavy and packed down well. Obviously, wading through the snow to get around on foot was extremely difficult - so much so that it became necessary to use crowbars and ice picks just to clean a path on the street. Maneuvering through, or just moving the snow, was such a monumental chore that even several ton railroad cars were "held prisoner in their houses". On the train tracks, freight cars were immobilized and abandoned across all of Southeast Lower Michigan. Temperatures held in the upper 20s to around 30 through the entire snowfall, with over two feet of snow reported on the ground. The strong northeast to north gale sculptured towering drifts of snow up to 12 feet high across the landscape .The howling wind averaged over 30 mph during the 24 hour period. The lowest barometric pressure reading noted was 29.60 inches at 11:00 AM on the 6th. This reading isn't too terribly deep or severe (the lowest pressure ever observed in Detroit was 28.34 inches during the late January blizzard of 1978), but the pressure was taken only five times daily (7:00 AM, 11:00 AM, 3:00 PM, 7:00 PM and 11:00 PM), so it likely fell lower. As the center of the low pressure drifted further north into the Great Lakes on the 7th, milder air from the south was drawn into Southeast Lower Michigan. The sky cleared as the wind shifted to the south and the temperature rose to 40 degrees, in spite of the very heavy snow cover. In the days following the storm, temperatures managed to push up well into the 50s and even reached the mid 70s by mid month, after all, this was April, right?
 
This storm stands as Detroit's biggest and severest snowstorm and is well summarized by the following quote in the journal and actually would still stand to this day. . .
"The storm was unprecedented in fierceness, snowfall and blockades in the history of the service and the oldest inhabitants can recall nothing to equal it".
 MAP 1 

Note copies of the 120 year old maps below, all under the "War Department" seal at that time. On the morning of the 4th, a large Arctic high pressure system /30.41"/ dominated much of the central and northern part of the US. The air with this high was unseasonably cold for early April with readings in the teens and 20s under it. A station in the western U P in Michigan reported 10 degrees. It was around the 20 degree mark here in Southeast Lower Michigan (normal lows average in the mid 30s for Detroit). Meanwhile, a north/south front over the Ohio Valley appears to have stalled with areas of low pressure riding up the front as a strong, southerly low level jet surges northward ahead of the front.

April 4th, 1886 7AM EST 


MAP 2

Note the series of low pressure systems that ride north-northeast out of the Gulf of Mexico in an upper air pattern that is also showing signs of stalling and deepening as an upper low pressure trough /500MB/ seems to be digging and forming into the Ohio and Tennessee Valleys. Our monster has now shown its face and of all places, far to the southeast over the panhandle of Florida !

April 5th, 1886 7AM EST


MAP 3 

On the morning of the 6th, note the massive surface storm system covering pretty much the eastern half of the country. This is also reminiscent of the our January 26-28th, 1978 storm in its deepening  intensity (though the ’78 storm central pressure bottomed-out deeper), estimated upper air pattern and extent of coverage.  Note the area of heavy snow and blizzard conditions over the Eastern Great Lakes with sky obscured in heavy, driving snow (shaded round circles, not black) as surface troughing extends northward up into Lake Huron as the surface low backs toward the Lakes Region.  This heavy snow scene replicates that of our 1974 storm   with its "conveyor-belt " analogy of moisture drawn from the Atlantic westward into the Eastern Great Lakes . The heaviest snow fell across extreme Southern Ontario, extreme Southeast Lower Michigan and extreme Northwest Ohio with the ’74 storm also and note how that same area is shaded here in  the 1886 storm. An estimated position of the 500 MB low is included (most likely very close, if not identical to the 1978 and 1974 storm) somewhere in the Upper Ohio Valley (Kentucky northward into the Eastern Great Lakes).  Note, the high pressure system has been squeezed northwestward into the classic "horseshoe" shape pattern, also reflective of the 1974 storm.

April 6th 1886, 7AM EST



Snowstorm and Cold Wave of April 5-6th 1982


April of 1982's weather started out normal enough across Southeast Lower Michigan with highs in the mid 50s and decent weather. Along about the 4th, the pattern began to change as an Arctic air mass hibernating across northern Canada began to push southeast in earnest, approaching the northern border states of the US. By the 5th, the high pressure made inroads into the Northern Plains and Great Lakes while a low and storm center began forming over Oklahoma with a trof northeast toward the southern Great Lakes. Temperatures in the Lakes region had plummeted into the teens and 20s that morning of the 5th.

By the morning of the 6th; the low had deepened and moved rapidly east northeast across the northern Ohio Valley pushing a wide area of snow into the cold air over the region. As the storm moved into the Northeast over Pennsylvania that morning; the central pressure had dropped to 992 MB. Across Southeast Michigan, generally 4-8" of snow fell over the area by mid day on of the 6th with temperatures in the lower 20s.  

April 5th 1982 Weather Map 





April 6th 1982 Weather Map




DETROIT LCD 1982



FLINT LCD 1982


April - Detroit Records 1874 - Present
April Normals
(1980-2010)
Maximum Minimum Average Daily
Temperature
Precipitation
Date Max Min Avg Record
High
Lowest
Max
Highest
Min
Record
Low
Highest Lowest Greatest Date
1 53 34 44.0 80/2010 27/1911 57/1967 14/1923 64/2010 24/1923 1.30/1959 1
2 53 35 44.0 83/1963 29/1899 58/1963 17/1881 71/1963 24/1881 1.44/1945 2
3 54 35 44.0 77/1999 30/1954 57/1981 14/1954 66/1981 22/1954 1.06/1980 3
4 54 35 45.0 74/1921 30/1881 54/1928 9/1874 64/1921 20/1874 1.06/2003 4
5 55 36 45.0 79/1921 29/1874 59/1929 16/1881 68/1929 24/1881 2.59/1947 5
6 55 36 46.0 83/1929 27/1982 65/1929 18/1982 74/1929 23/1982 2.41/1886 6
7 56 36 46.0 83/1991 25/1972 63/1929 10/1982 72/1929 21/1982 0.92/2010 7
8 56 37 46.0 79/2001 32/1920 59/2001 11/1982 69/2001 24/1982 0.94/2002


April - Flint Records 1921 - Present
April Normals
(1980-2010)
Maximum Minimum Average Daily
Temperature
Precipitation
Date Max Min Avg Record
High
Lowest
Max
Highest
Min
Record
Low
Highest Lowest Greatest Date
1 51 31 41.0 79/2010 32/1992 56/1967 7/1923 66/2010 21/1923 1.14/1929 1
2 51 31 41.0 82/1963 32/1992 55/2010 16/1924 69/1963 26/1992 1.62/1945 2
3 52 31 42.0 79/1999 28/1954 57/1981 11/1954 67/1999 20/1954 1.03/1926 3
4 52 32 42.0 77/1921 30/1944 56/1928 13/1995 65/1928 0/1999 1.51/2003 4
5 53 32 42.0 80/1921 28/2007 57/1929 13/1995 67/1929 25/2007 2.05/1947 5
6 53 32 43.0 83/1921 27/1982 64/1929 16/1975 73/1929 23/1982 1.73/2010 6
7 54 33 43.0 83/1929 27/1972 60/1991 6/1982 72/1929 18/1982 0.87/2010 7
8 54 33 44.0 76/1991 32/2007 52/1991 8/1982 64/1991 23/1982 0.91/2002 8


April - Saginaw Records 1912 - Present
April Normals
(1980-2010)
Maximum Minimum Average Daily
Temperature
Precipitation
Date Max Min Avg Record
High
Lowest
Max
Highest
Min
Record
Low
Highest Lowest Greatest Date
1 49 31 40.0 81/2010 29/1924 55/1999 8/1923 67/2010 22/1923 1.09/1959 1
2 50 31 41.0 82/2010 30/1936 58/2010 15/1954 70/2010 25/1936 1.17/1945 2
3 50 32 41.0 82/1999 26/1954 56/1981 11/1954 64/1981 19/1954 1.20/1982 3
4 51 32 41.0 76/1921 29/1982 55/1929 15/1954 64/1921 23/1982 1.13/1947 4
5 51 32 42.0 79/1921 28/1982 59/1929 14/1995 68/1929 23/1982 1.45/1917 5
6 52 33 42.0 81/1929 28/1982 66/1929 16/1982 74/1929 22/1982 0.93/1988 6
7 52 33 43.0 81/1991 26/1972 60/1991 12/1982 71/1991 23/1982 0.84/1928 7
8 53 33 43.0 74/1931 29/1914 50/1981 17/1950 59/1929 24/1914 1.19/1991 8


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



3/31/18

Where is Spring?

That's the question I hear most the past several weeks: Where is Spring? We are already closing in on a month of climatological spring and well over a week by the calendar (which really matters little in the scheme of climate). March will go down with below normal in temperatures, averaging around one to three degrees below across Southeast lower Michigan - this coming after a slightly colder than average winter. Look for my winter and cold season /Nov-Mar/ review after the snow finally ceases, generally mid-late April.

I've posted a few times, first back in the fall in the Winter 20017-18 Outlook, that springs tended to be notably later after the winter analogue periods. Just looking at the average temperatures from those years shows a preference for a later spring, especially temperature averages in April /ave departure -1.2/. The temperature trends from March and April (gray to blue shadings show an overall trend for normal to below temperatures).

DetroitFEBMARAPRMAY
1890-9130.630.848.355.7
1893-9423.640.447.656.3
1898-9919.829.3*45.459.8
1910-1128.833.750.564.7
1917-1824.539.644.662.4
1950-5127.736.546.059.9
1955-5628.132.445.756.0
1971-7224.632.644.660.3
1975-7633.340.450.056.4
1984-8523.438.451.060.1
1999-2000 31.944.048.061.8
2000-0126.735.151.261.2
2008-0928.538.749.859.4
2011-1232.650.7*49.460.7
AVE27.436.948.059.6
NORM28.137.249.259.7
DEP-0.7-0.3-1.2-0.1


The good news is that there also is a trend toward a more normal spring temperatures as we get later into spring /later April into May/ and is reflected on May's departures - and hopefully that will again be the trend this year.

In the near future however; it's more of a late winter pattern than spring pattern for the Great Lakes this upcoming week as evidenced by the projected upper wind patterns. There's certainly no question as to where our main air mass projected, originated.
















This is the possibility of system bringing some rain or wet snow over the area toward week and again, late week. All I can say is gardeners and spring weather enthusiast hold on, it's going to be a bumpy week!

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



2/28/18

Update 3/1 - March to Arrive Like the Veritable - or is it Irritable - Lion!

3/2 -Actual snowfall from 3/1/18 storm.

 

___________________________________________________________________________


3/1 - 10AM EST - Update

Latest indications are going forecast looks good but will tweak the area involved and amounts up slightly. The heaviest area of snowfall should extend across Washtenaw and Wayne counties into portions of Livingston, Oakland and Macomb. Generally 4-7" are likely in these areas rather than 3-6" due to change-over likely a bit earlier in some areas. Isolated locations better than 7" possible in areas where snow accumulates on faster due to lower air/ground temperature. Be advised the snow will be wet and heavy as temperatures fall slowly into the lower 30s by evening. Also; a period of rain mixed with snow and sleet is possible before the change-over.

2/28 - 230PM EST

After beautiful, early spring-like weather these past several days; winter will roar back for the first day of March with strong, gusty east-northeast winds shifting to north, rain - moderate to heavy at times - and to top off the day; snow some of it coming in moderate to heavy bursts. Since rivers were and still are on the higher side, how much rain/snow that ultimately falls may aggravate earlier problems. For the latest river data; follow the NWS River statements and forecasts if issued. Another issue that may crop up will be the potential of ice pushing west and jamming along with higher water levels along some of the shore waterways due to the strong east winds backing to northeast, then north by late in the day. Fortunately, the system will be fairly quickly moving so the conditions won't be long lasting.

My interest in the possibility of the stormy system was first sparked back last Sunday while looking at the models and remarking to my a few of my colleagues. There was a possibility, in my view of the beginning process of phasing of jets over the southern Great Lakes as a low moved across the Northern Ohio Valley/Southern Great Lakes. I will say; the models have had a devil of a time trying to project how much cold air would be available at the surface and even more importantly, aloft. This is not surprising as I have witnessed other late winter scenarios where this was a problem. This combined with the vertical lift and available moisture was setting the stage for a potential big mess Thursday into Thursday night. With the jet folding and phasing of the polar stream and subtropical, this is, at the very least one of the more complex systems this winter.

Since this forecast has been somewhat difficult for some of the main models to come to a general consensus; especially snowfall - where and how much - let's look at the most recent projections of the GFS and NAM together and my preferred forecast & maps . Note the GFS & NAM models have stepped up in a consensus.

 Upper jet /500 MB/ @ 1PM Thu 3/1 

PREFERRED                                                                                                        PREFERRED
 








                                        

 Surface Maps @ 1PM Thu 3/1

PREFERRED










Snowfall Totals @ 1AM 3/2


 PREFERRED SNOW AMOUNTS


PREFERRED PLACEMENT



To the NAM's credit, the GFS has been the most erratic in both placement and amounts the past few days. The GFS has projected the snow to fall mainly over the central and even northern part of Lower Michigan. This action actually follows it's pattern this winter with major storms and in my opinion, has been the more unreliable performer of storms followed between it and the NAM. The European has also been more erratic this winter. Looking at the latest 12Z data, The NAM appears aggressive with snow amounts and doesn't take a realistic account the warmer grounds and low level temperature. However; following the models all week, it seems to me it had a better handle on earlier upper jets and snow placement but not amounts.

I'll update later today on my Facebook Weather Historian page with mainly shorter term models


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


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