There's no doubt about it; besides the more typical climate statistics for the month of January ("warmest, wettest, etc etc), January 2017 had more to offer than the usual headlines.
True, January 2017 was the 12th warmest January on record at Detroit and Flint, while being the 15th warmest at Saginaw. Abundant rainfall of 3.13" made January the 6th wettest in Flint and while both Detroit and Saginaw had above normal rains, the top 20 list was not breached. Snowfalls were near to slightly below normal in most regions.
Elaborating on the oddities mentioned in the my article on January recently (below); January 2017 was also a stand-out month for any January (and other months) with cloud cover, lack of sunshine, dense fog and thunderstorms. Digging back over my records
for Detroit, show that January 2017 was indeed lacking in sunshine due to the cloud cover.
The sunshine normals or
historical data is available up through June 1995. The sunshine switch was then removed from DTW and placed in at DTX. However, due to frequent errors in readings after the move, it was later terminated and dismantled. Past sunshine minutes, percentages and normals were last printed in the 1995 DTW Annual LCD. Again, this was after the NWS moved out
of DTW and DTW became a Contract Station.
January's cloud cover, sunrise to sunset /sr - ss/ is on the
monthly F6 below and totaled 8.8 or rounded off to 9, out of a possible 10. January 2017 had 26 cloudy or mostly cloudy days, 3 partly cloudy days and just 2 clear or mostly clear days. This compares to the averages or normals for January sky conditions/as follows: the 125 year ave /1871-1995/ amount of cloudy
days in January sunrise - sunset /sr-ss/ averages to 20, there are 7 partly cloudy days and 4 for clear. The 105 year average /1891-1995/ of possible sunshine in Detroit for January stands at about 36% while the 110 year average /1886-1995/ cloud cover for January is around 7.5 tenths.
Therefore yes January was a gloomy month - but a record?
PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6)
STATION: DETROIT MI
MONTH: JANUARY
YEAR: 2017
LATITUDE: 42 13 N
LONGITUDE: 83 20 W
TEMPERATURE IN F: :PCPN: SNOW: WIND :SUNSHINE: SKY/WX :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 41 23 32 6 33 0 0.00 0.0 0 5.9 14 210 M M 2 18 17 190
2 43 27 35 9 30 0 0.08 0.0 0 6.4 12 90 M M 9 18 17 90
3 45 38 42 16 23 0 0.36 0.0 0 8.1 18 290 M M 10 12 24 280
4 38 19 29 3 36 0 0.01 0.2 0 19.3 24 280 M M 10 46 280
5 20 12 16 -10 49 0 0.03 0.7 T 12.2 21 250 M M 9 8 24 270
6 17 8 13 -13 52 0 T T T 9.1 16 240 M M 8 18 29 270
7 17 5 11 -15 54 0 0.02 0.7 T 11.2 21 310 M M 7 89 28 310
8 18 8 13 -13 52 0 0.00 0.0 1 10.0 17 290 M M 5 23 280
9 31 16 24 -2 41 0 T T 1 12.4 21 210 M M 10 25 220
10 49 27 38 12 27 0 0.53 3.0 3 20.2 41 250 M M 10 1246 53 260
11 57 29 43 17 22 0 0.13 0.0 0 13.9 33 250 M M 9 138 42 240
12 58 29 44 19 21 0 0.40 0.0 0 11.4 29 230 M M 10 13 42 220
13 29 20 25 0 40 0 0.00 0.0 0 8.1 17 280 M M 10 23 280
14 33 23 28 3 37 0 0.00 0.0 0 4.4 10 80 M M 8 13 90
15 34 18 26 1 39 0 0.00 0.0 0 3.9 9 200 M M 3 18 12 220
16 36 19 28 3 37 0 0.15 0.0 0 3.3 13 100 M M 9 168 16 100
17 48 33 41 16 24 0 0.42 0.0 0 8.6 18 250 M M 9 1236 23 240
18 43 35 39 14 26 0 T 0.0 0 11.0 18 220 M M 10 1 24 210
19 38 33 36 11 29 0 0.00 0.0 0 7.8 17 240 M M 10 18 21 240
20 42 33 38 13 27 0 0.16 0.0 0 5.7 13 60 M M 10 12 16 60
21 59 40 50 25 15 0 T 0.0 0 3.2 10 170 M M 7 128 13 180
22 49 40 45 20 20 0 0.00 0.0 0 3.9 9 80 M M 10 12 11 60
23 46 41 44 19 21 0 0.11 0.0 0 7.3 13 60 M M 10 12 16 50
24 42 39 41 16 24 0 0.04 0.0 0 7.2 17 310 M M 10 12 22 300
25 48 36 42 17 23 0 0.01 0.0 0 10.1 29 230 M M 10 18 35 220
26 42 35 39 14 26 0 T T 0 16.1 26 230 M M 10 4 32 250
27 35 28 32 7 33 0 0.01 0.1 0 14.7 24 260 M M 10 46 32 240
28 31 28 30 4 35 0 0.02 0.5 T 13.8 20 230 M M 10 189 25 240
29 30 25 28 2 37 0 0.05 2.0 1 7.2 15 300 M M 10 18 19 310
30 27 18 23 -3 42 0 0.06 1.4 2 7.0 14 190 M M 9 1 19 240
31 36 26 31 5 34 0 0.24 3.2 6 9.1 17 270 M M 10 18 32 280
================================================================================
SM 1182 811 1009 0 2.83 11.8 292.5 M 274
================================================================================
AV 38.1 26.2 9.4 FASTST M M 9 MAX(MPH)
MISC ----> # 41 250 # 53 260
================================================================================
NOTES:
# LAST OF SEVERAL OCCURRENCES
COLUMN 17 PEAK WIND IN M.P.H.
PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6) , PAGE 2
STATION: DETROIT MI
MONTH: JANUARY
YEAR: 2017
LATITUDE: 42 13 N
LONGITUDE: 83 20 W
[TEMPERATURE DATA] [PRECIPITATION DATA] SYMBOLS USED IN COLUMN 16
AVERAGE MONTHLY: 32.1 TOTAL FOR MONTH: 2.83 1 = FOG OR MIST
DPTR FM NORMAL: 6.5 DPTR FM NORMAL: 0.87 2 = FOG REDUCING VISIBILITY
HIGHEST: 59 ON 21 GRTST 24HR 0.57 ON 16-17 TO 1/4 MILE OR LESS
LOWEST: 5 ON 7 3 = THUNDER
SNOW, ICE PELLETS, HAIL 4 = ICE PELLETS
TOTAL MONTH: 11.8 INCHES 5 = HAIL
GRTST 24HR 3.2 ON M 6 = FREEZING RAIN OR DRIZZLE
GRTST DEPTH: 6 ON 31 7 = DUSTSTORM OR SANDSTORM:
VSBY 1/2 MILE OR LESS
8 = SMOKE OR HAZE
[NO. OF DAYS WITH] [WEATHER - DAYS WITH] 9 = BLOWING SNOW
X = TORNADO
MAX 32 OR BELOW: 9 0.01 INCH OR MORE: 19
MAX 90 OR ABOVE: 0 0.10 INCH OR MORE: 9
MIN 32 OR BELOW: 20 0.50 INCH OR MORE: 1
MIN 0 OR BELOW: 0 1.00 INCH OR MORE: 0
[HDD (BASE 65) ]
TOTAL THIS MO. 1009 CLEAR (SCALE 0-3) 2
DPTR FM NORMAL -214 PTCLDY (SCALE 4-7) 3
TOTAL FM JUL 1 2987 CLOUDY (SCALE 8-10) 26
DPTR FM NORMAL -533
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
CLOUD COVER & SUNSHINE
RECORD NUMBER OF CLOUDY DAYS /AVERAGE FOR MONTH/ AT DETROIT FOR *JANUARY AND **ALL TIME
MONTH & YEAR NUMBER
* JANUARY
1960
9.3
1-**NOVEMBER 1985
9.3
**JANUARY
1960 9.3
**DECEMBER 1929 9.3
2-**NOVEMBER 1992 9.2
9- JANUARY 2017
8.8
(JANUARY 1932 8.6)
RECORD FOR LEAST AMOUNT
OF SUNSHINE AT DEROIT FOR *JANUARY AND
*ALL TIME
MONTH & YEAR NUMBER
* JANUARY 1932 14%
1-**DECEMBER
1929 7%
2-**NOVEMBER
1985 13%
? JANUARY 2017
N/A
November 1985,
January 1960 and December 1929 all tie
for the cloudiest month ever in Detroit. January 2017 doesn't even come
close to the cloudiest month nor cloudiest January with 8.8 cloud cover /9th place/.
Looking at the
previous sunrise-sunset cloud cover records and least sunshine records above, we can basically be assured that
January 2017 would not have placed for the least sunniest month (December 1929
has that honor). How about the least sunniest January?
January 2017 is a just a contender for the least sunniest January by the following reasoning...
Obviously, it's difficult to
say how much sunshine Detroit had in January 2017 since it wasn't recorded locally and doesn't
always correlate or is the inverse of cloud cover. Case in point from above: Lowest
sunshine on record for January is 14% in 1932 but this occurred with less cloud
cover at 8.6 as opposed to the 16% of sunshine in January 1960 with a higher
amount of cloud cover at a record 9.3! If one was only to go by a direct correlation by cloud cover and subsequent lack of sunshine alone; then there is a higher chance, January 2017 contained less sunshine than January 1932. However it isn't always that simple...
Here's where being an older-timer weather observer has its merits, so try to follow along...
It really has to do more to do with the type of clouds and their thickness observed during the day/month and resulting opaqueness. In the "old days" of the NWS, observations of cloud cover was recorded in both total coverage and opaqueness of the total; say for example 10/10 of cirrostratus (usually a high but partially thin cloud cover) and its opaqueness, might be 10/5. Therefore the observation read something like; 200-OVC (or in the teletype days when I started, it was 200-O with a cross in the middle - sent out and read on teletype but not displayed on a weather map). The symbol (-) was read as thin, when the opaqueness of a cloud cover was half or less. Basically meaning; one could discern the blue sky above (or stars/moon at night). With the advent of ASOS, the thinner parts of all types of cloud cover was lost in the observation. This is where the human element of a weather observation was better to discern the actually cloud cover and its thickness. Clouds above 12,000ft are not officially observed on ASOS therefore some mid clouds and all high clouds are lost - and certainly their opaqueness! This was/is crap to most pre-ASOS days weather observers and many other weather aficionados. Wtih ASOS, sometimes the higher clouds are still augmented (edited) into the ASOS where human observers are co-located with ASOS.
Ok, back to the subject at hand...
The absolute
dreariest month for sunshine happened after the stock market crash of 1929 when
December 1929 had only 7% of the possible (well below anything other month). I guess mom nature got in on the
mood around metro Detroit and the country. Keep in mind, the month
of December 1929 has the least amount of possible sunshine during any given December and month. Therefore;
December 1929 with just 7% of the possible was indeed, the gloomiest month. Another
interesting tidbit for December 1929; however was its Christmas was one of the
whitest in Detroit's history with 11 1/2" of snow on the
ground.
And talk about down right depressing:
It
should be noted that November and December 1972 have the record for the
gloomiest period /60 days/ in what I could find in both cloud cover and
subsequent sunshine (or lack there-of).
MONTH & YEAR NUMBER
NOVEMBER 1972 9.1
DECEMBER 1972 9.0
MONTH & YEAR SUNSHINE (%)
NOVEMBER 1972 13%
DECEMBER 1972 13%
So, you see this past January wasn't so bad. There were other times during the 1970s in the winter I recall cloudy, dreary months around here and stats back me up; November 1977 /9.1/ December 1974 /8.7/ and actually it didn't end there in the monthly stats. The whole year of 1972 had 7.1 cloud cover for the cloudiest year on record at Detroit with 1984 a close second at 7.0. More 1970's show up here for cloudier years too, 1970 and 1973 at 6.9, 1974 at 6.8. Actually it sort of follows; being that some of the years in the 1970s, tended to be a bit more stormy in both winter and severe weather seasons...there'd also be more cloud cover. And, that leads me to thunderstorms in January...
RECORD NUMBER OF
THUNDERSTORM DAYS FOR JANUARY
YEAR NUMBER
2017 3
1909 3
1907 2
Thunderstorm days in
January while not unheard-of are fairly rare with an average since 1871 of
just about .2 (or well less than one day in January). Therefore you can reason, that
January thunderstorms days are few and far between.
RECORD NUMBER OF
DENSE FOG DAYS DETROIT FOR *JANUARY AND **ALLTIME
DENSE FOG RECORDS
MONTH & YEAR MOST DENSE FOG DAYS
* JUNE 1973 9
**JANUARY
1907 8
JANUARY 2017 8 /TIED WITH 1907 &
THUS SUPERSEDES/
There were 8 days total during the month of January (20-24th, 5 dense fog days in a
row) which was also very rare. Occurrences of dense
fog in January is 2 days on average. January 2017 totaled just one day less the the all time record for dense fog days which belongs to June of 1973. However; January tied for first place for the month of January with 8 days which was also observed in January 1907. Just for an extreme comparison; there were only 6 days in all of 2015 that dense fog was recorded at DTW. The annual average for the year is about 17 days for dense fog.
Previous Preliminary January write-up through January 22nd...
"Strange January to Get back on Track Later This Week"
It's been an odd and very variable January this year. The first several
days started out mild, then a cold blast commencing on the 5th reminded
Southeast Lower Michigan inhabitants what month it really was with
temperatures well below normal - but that didn't last long did it? We
turned the corner by the 9th and again, it was off to the races to
warmth with high temperatures basically in the 50s for three days before
a slight 4-day cool down took hold through the 16th. Since then;
readings have continually averaged above or well above normal through
the 21st /yesterday/. In fact; Detroit's high on the 21st of 59 reached
the peak reading thus far for the month, making that the third upper
50-degree temperature this month! Not to be a record however as that
honor belongs to Jan 21st of 1906 with 65! If we're going to speak of
records, Flint's high temperature of 54 on the 21st came within one
degree of its 55 degree record in 1954.
In the midst of January's wild roller-coaster ride of frequent up and
down temperature swings; came just as many resulting weather phenomena -
some typically seen and some not during January. Snow and cold of
course, ranks on the side of normalcy in January; whereas balmy
spring-like temperatures interspersed through the month, thunderstorms
and many dense fog days do not. Oh sure they happen in January; and if
at any time, usually during our cyclical January thaw which comes
regularly enough to nudge up temperature records in past data during mid
to late month for several days. However, there's certainly been more
than a weeks duration of thawing weather this January with several
notable upward temperature swings during the month. So much so, that
even with the bitter cold experienced earlier in the month, readings are
averaging 4 - 5 degrees above normal and enough so; that we are
beginning to enter the top 20 warmest January's list at all three
stations in the bottom (upper teens to 20). Three thunderstorm days have
ranked up this month thus far at Detroit, an unusual amount being its
the dead of the winter. Dense fog days have just eclipsed (6/5-as of the
22nd) the number of snow days thus far in January with nearly a week
total in days where visibilities at Detroit Metro Arpt dropped down to a
1/4 mile or less. Last night (21st-22nd) being the foggiest I've seen
it in quite awhile around metro Detroit. Dense fog advisories have been
carried/existed since Saturday evening /21st/ (now Sun eve night, 22nd).
The snow machine sputtered the first ten days of the month but then died
completely after the tenth. What had been a relatively snowy winter
thus far into early January went bye-bye since, with 4.6" recorded the
first ten days at Detroit. Flint did a bit better with 5.7" and Saginaw
topped it with 7.4" To be fair; all three climate stations still are
above normal for the snow season of 2016-17 by about 2-4" - but don't
look for much of any addition this week as temperatures hold basically
above normal with mainly rain expected until about Friday. The better
chances for any addition of light snow will be across the northern
portions of Southeast Michigan but then, rain is expected to mix with
the snow, which should cut down any appreciable accumulations. Actually
more rain than snow days have been observed this month with all of
Southeast Lower Michigan having a wet January thus far. Detroit is
nearly an inch above normal (a decent departure for January); Flint is
nearly an inch and a half above while Saginaw rests at about three
quarters above average".
Note; Due to the lack of records for some weather items in Detroit's LCD since 1995, some records were estimated using very long term records which were then, updated.
Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian
