9/20/19

Summer of 2019 - Started Cool and Wet; Ended Warm and Drier Record or Near Record Great Lake Water Levels

Summer of 2019 really started out on a down beat note with exceptionally cool weather relative to normal the first two-thirds of June. A one point (around the calendar beginning of summer); temperatures averaged over 3 degrees below normal. That may seem like small departure but for a summer month that was enough (at that point) to come close to the top 20 coolest Junes. The 20th coolest June temp ave is 64.8 and by the 21st we were in the mid 60s. The last week of June reversed course similar to some of the cooler and normal analogues to only average a solid degree below normal /68.2, -1.2/.

The analogue sample projected an ave of /68.6, -0.8/ with five below normal Junes (a degree or more). There were also five above normal Junes which complicated the call but the average and also trend for June was still below normal averaging about a degree /-0.8/ with warming later in the month prevalent.

From my Summer Outlook:
 
Let's start with June; a cool or below normal June? That's what all my data is pretty well showing; from analogues, to current and projected upper air patterns, CFS Climate model which looks out over  most of June and CFSv2 model, for all of June. Can't argue much with that; though anything can happen we all could be wrong ;-). Let's hope we can slide by with a "closer to normal" June. Also, many times changes occur mid or late month and this June could very well be one of those and warm up with time.


Even though they were just as many cool Junes as warm Junes in the analogues (5/5); the difference here was the cool June departures were more notable than the warm departures for June. The five cool Junes averaged in at 64.7; well below the June norm of 69.4. These cool Junes averaged just under five degrees below normal and were precisely why the average for all of the June sample came in below normal also, at 68.6 /-0.8/. On the flip-side; the warm June's averaged in at 71.9 or 2 1/2 degrees above the June normal (or just about half of the cool departure). There was just a couple of normal Junes in the 12 numbered sample.







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

                                          STATION:   DETROIT MI
                                          MONTH:     JUNE
                                          YEAR:      2019
                                          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  78  61  70   5   0   5 0.64  0.0    0  6.5 30 270   M    M   9 138    38 280
 2  72  53  63  -2   2   0    T  0.0    0 10.3 18 300   M    M   6 18     24 290
 3  67  45  56 -10   9   0 0.00  0.0    0  7.4 16 170   M    M   3        20 170
 4  75  51  63  -3   2   0 0.04  0.0    0  7.1 21 230   M    M   9 18     26 240
 5  83  62  73   7   0   8 0.17  0.0    0  9.2 24 340   M    M   9 138    35 310
 6  73  58  66  -1   0   1 0.00  0.0    0  4.7 12 360   M    M   9 18     14 350
 7  79  57  68   1   0   3 0.00  0.0    0  7.9 16  60   M    M   6 18     22  50              
 8  81  57  69   2   0   4 0.00  0.0    0 10.4 18  70   M    M   7        26 100
 9  77  67  72   4   0   7 0.04  0.0    0  7.4 14 240   M    M  10 18     18  70
10  73  55  64  -4   1   0 0.17  0.0    0 11.0 25 290   M    M   9 18     32 300
11  78  49  64  -4   1   0 0.00  0.0    0  6.4 16 300   M    M   2        23 250
12  77  58  68  -1   0   3 0.05  0.0    0  8.3 18 330   M    M   8 1      23 170
13  64  52  58 -11   7   0 0.15  0.0    0  8.3 21 320   M    M  10 18     28 320
14  75  48  62  -7   3   0 0.00  0.0    0 12.1 23 220   M    M   7        32 240
15  71  61  66  -4   0   1 0.04  0.0    0 12.2 22 210   M    M  10 18     29 210
16  64  56  60 -10   5   0 0.44  0.0    0  7.3 14  40   M    M  10 18     18  40
17  73  58  66  -4   0   1    T  0.0    0  3.9 12  10   M    M  10 8      15 360
18  78  58  68  -2   0   3 0.00  0.0    0  3.0 12 160   M    M   8 8      15 150
19  81  61  71   0   0   6    T  0.0    0  4.3 12 170   M    M   9 18     15 180
20  68  57  63  -8   2   0 0.51  0.0    0  8.9 17 360   M    M   9 1      23 350
21  78  55  67  -4   0   2 0.00  0.0    0  7.4 15 330   M    M   5        18 320
22  77  54  66  -5   0   1 0.00  0.0    0  5.8 12  90   M    M   5 8      17 120
23  79  54  67  -5   0   2    T  0.0    0  5.9 14 170   M    M   6        19 120
24  81  67  74   2   0   9 0.06  0.0    0 10.2 29 250   M    M   8 1      35 250
25  85  63  74   2   0   9 0.00  0.0    0 13.4 25 280   M    M   4        31 260
26  87  67  77   5   0  12 0.00  0.0    0  8.4 17 240   M    M   6        24 260
27  88  68  78   6   0  13    T  0.0    0  4.1 22 250   M    M   6 38     31 250
28  91  68  80   7   0  15 0.53  0.0    0  5.2 29 300   M    M   7 38     38 290
29  89  72  81   8   0  16 0.02  0.0    0  7.6 16 310   M    M   6 138    21 290
30  86  69  78   5   0  13    T  0.0    0  6.4 15  10   M    M   6 8      21  20
================================================================================
SM 2328 1761        32 134  2.86     0.0 231.0          M      219
================================================================================
AV 77.6 58.7                               7.7 FASTST   M    M   7    MAX(MPH)
                                 MISC ---->  # 30 270               # 38  280
================================================================================
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:    JUNE
                                          YEAR:     2019
                                          LATITUDE:   42 13 N
                                          LONGITUDE:  83 20 W

[TEMPERATURE DATA]      [PRECIPITATION DATA]       SYMBOLS USED IN COLUMN 16

AVERAGE MONTHLY: 68.2   TOTAL FOR MONTH:   2.86    1 = FOG OR MIST
DPTR FM NORMAL:  -1.2   DPTR FM NORMAL:   -0.66    2 = FOG REDUCING VISIBILITY



While rainfall at Detroit Metro was 2/3 of an inch below normal it was more of an outlier as much of the region saw normal to well above as evidenced by the map below. Severe weather was limited for June and in fact; much of the summer. One event that the NWS DTX has recorded occurred on the first calendar day of the summer June 1st.



 

.https://mrcc.illinois.edu/cliwatch/months/m06_19.pperc.png

While rainfall at Detroit Metro was 2/3 of an inch below normal it was more of an outlier as much of the region saw normal to well above as evidenced by the map below. Severe weather was limited for June and in fact; much of the summer. One event that the NWS DTX has recorded occurred on the first calendar day of the summer June 1st.

The month of July did an about face with above normal temperatures prevailing. The following map clearly shows the extent of the warmth with temperatures over Southeast Lower Michigan averaging 1 - 3 degrees degrees above normal. This was also the call in the analogues and Outlook


Things started to heat-up in July as well they should with six Julys above normal, averaging better than two degrees. The normal Julys placed a close second with five in number with only one cool July - a far cry from June's stats. Overall, the twelve Julys averaged +0.6 above normal but again not enough to declare the month - by average - a categorized above normal month (>+1.0). Still, there were quite a few notably warm Julys with the above normal six averaging 75.8 or better than two /+2.2/ above normal. (mention 76 degree summers).


The prevalent warm July's in the analogues averaged nearly 3 degrees above normal. 


https://mrcc.illinois.edu/cliwatch/months/m07_19.tdev.png 

Rainfall during July was quite variable with some areas getting dumped on by heavy storms while the majority of Southeast Lower Michigan beginning to dry out after month's of wetter conditions. While much of the region averaged below normal rain. A band of thunderstorms with wind damage and very heavy rain the region on the 2nd and 20th of July. Severe weather reports can be found here at the NWS DTX for July 2nd & July 20th.

As was found in the 12 previous summer months, August also followed the temperature pattern researched in the analogues. Hot spells backed off some and thus; the average temperature for August was just a degree /1.1/ above normal with an average of 73.1. All of Southeast Michigan shared in the near normal regime. From the Outlook...


By August; a bit closer to a normal temperatures were found but with the above normal Augusts just winning out at five; there were four normal Augusts and three cool Augusts. Average temperatures dropped slightly to 72.3 for all 12 August months.  However; again like the Julys, the warmer, above normal Augusts averaged at 74.7; nicely above /+2.7/ over the 72.0 norm.


 https://mrcc.illinois.edu/cliwatch/months/m08_19.tavg.png


Rainfall continued sporadic in August with normal to above central and south; below in the Saginaw Valley. While no severe weather has been documented at DTX in event summaries; a narrow band of regenerating storms with torrential rains hit the North-Northeast on August 12th (see map of Metro Detroit) created flooding in the targeted areas near and north of the Walter Reuther Freeway. 

August 12th

___________________________________

 https://mrcc.illinois.edu/cliwatch/months/m08_19.pperc.png

SUMMER 2019

Much of Michigan (including Southeast Lower Michigan) had a relatively normal summer as far as temperatures with reading averaging around a degree of normal.



Rainfall was somewhat sporadic but on the whole averaged around normal to slightly above for the Lower Peninsula; below normal west and around normal was seen east in the U.P. In Southeast Michigan; pockets of below average were also observed within the normal to slightly above, especially in the Thumb.






SUMMER 2019 - FACTS AND FIGURES





Summer Analogue Verification

Comparisons of analogue temperature projections to actual at Detroit find some interesting parallels and differences. As noted above, the researched temperature trend and subsequent forecast for all of Southeast Lower Michigan worked very well compared to normal. Basically, the summer had a cool beginning; warm middle and typical temperate end. 

As far as actual temperatures in the Summer Outlook the following was forecast:




Temperatures:

Overall; I look for temperatures to average around normal or within -1 1/2 to +1 1/2 degrees of the normals for Southeast Lower Michigan. As far as the patterns researched and analogue projections; see my Temperature trends discussion under analogues.
 

As shown by the state and Southeast Michigan temperature departure map and Detroit departure of +1.0; verified. Temperature actual pattern; verified.





Rainfall:

Look for the general pattern of above normal rainfall to continue into the summer across Southeast Lower Michigan. Analogue summers showed many wet summers with rainfall a couple of inches above normal on average. As far as the pattern researched and analogue projections, see my Rainfall trends discussion under analogues.

As shown by Southeast Lower Michigan's precipitation departure map; most areas saw normal to above rainfall but with notable exceptions; therefore a mixed verification. Given the perplexity of rainfall forecasts for a summer this isn't surprising.






I'll end the summer discussion on an quirky rainfall statistic result at Detroit. Metro Detroit Arpt /DTW/.The summer total rainfall indeed ended below normal with 8.63 /-1.26/. If you'll note the three other drier summers; they all averaged in a unusually tight range of only a few hundredths in the mid 8.60's. Here's the fourth now this summer; at 8.63. Remarkable



Many Great Lake Levels Highest in Recorded Modern History

Great Lakes, Lake St. Clair break 100-year-old water level records

Excellent articles on scattered places around the Lakes in the NY Times...


Great Lake Levels and Projected Levels into October 
US Army Corps of Engineers - Detroit District

The majority of the Great Lakes have entered their seasonal declines at this time but levels are still relatively high compared to long term averages. Lake Superior and Lake St. Clair are both forecasted to be an inch above their highest monthly average for September on the 13th, with Lake Erie forecasted to be 2 inches above. Lakes Michigan-Huron and Ontario are predicted to be only 5 inches below their highest monthly average for September on the 13th. Lake levels are forecasted to continue their seasonal decline headed into October with predicted net decreases of 1 inch on Lake Superior, 3 inches on Lake Michigan-Huron, 5 inches on both Lake St. Clair and Erie, and 8 inches on Lake Ontario. See our Daily Levels web page for more water level information.



BRIEF AUTUMN OUTLOOK

Well since the analogues overall did well in the summer; what about the fall? Granted the hemispheric patterns based on a weakening El Nino are getting long in the tooth but since the ENSO is fading into to basically a Neutral state, little affects are the norm. And, not surprising that's what came up in the analogues; normal. Actually; under our category numbers; normal to below dominated along with drier than normal conditions.





TEMPERATURES 




At five cooler than average analogue falls, four normal and three above; the autumn temperature projection is pretty well split with a balance at normal at 52.9 /+0.1/.  Though below normal falls topped the count at five; the actual average statistic came in a hair above normal but well within the normal range of a degree (+/- 1.0).  




Therefore; generally a typical but nice overall autumn is expected but we'll follow the trend of the analogues with a warmer beginning; then normal to below as we advance through mid to late fall. Look for temperatures to average -1.0 to +1.5 of the statistical norm.


PRECIPITATION


Clearly, our analogues project a drier than normal fall with an average departure of -2.00". The drier falls were accompanied by three normal or average rainfall autumns and just one above normal /2003/ at 9.98". Though this September has started out on the wetter side; this wet then dry pattern started mid summer and is typical into the fall. Analogues suggested even with wetter Septembers; still normal to below rainfall dominated in the fall with the exception of 2003.

Therefore; a two-tier range seems suitable with normal to below but with the emphasis on below.


Notable Dates Autumn into Winter:


Autumn Begins: Later this year; Mon - Sep 23rd at 3:50 AM EDT
Halloween:  Thu - Oct 31st
Thanksgiving:  Late this year; Thu - Nov 28th

Winter Begins: Sat - Dec 21st 11:19 PM EDT
Christmas: Wed - Dec 25th
New Years Day - Wed Jan 1st 2021

Look for the important Winter 2019-20 Outlook early - mid November