Apr 6, 2015

50TH ANNIVERSARY OF THE PALM SUNDAY TORNADO OUTBREAK OF 1965 AND RECALLING THE SUPER OUTBREAK OF 1974

Fifty years ago on Palm Sunday, April 11th 1965, even though just a child, I recall that the afternoon and evening's violent display of weather; once again sparked my interest in weather while riding back in the car from my grandparents in Marine City (along the St. Clair River). The churning, violent sky gave birth to vivid lightning as it cascaded across the sky. I remember my dad trying to tune into the AM radio stations to little avail as static from continuous strikes of lightning plagued the airways. Little did I know, decades later I would write about that terrible outbreak back in 2005 while in the NWS, updated in 2012 and 2015.

In addition, I included the Super Outbreak of 1974 (anniversary, April 3) written by NOAA/NWS in that Palm Sunday Outbreak 1965 article (see below).  I remember the 1974 Outbreak much more vividly as I was in my first year with the NWS. Fortunately for us; Southeast Michigan was on the extreme northern fringe of that terrible Outbreak. And finally; up until April 27, 2011 which exceeded it, it was known as the worst tornado outbreak ever to hit the country. 

Coincidentally and rather eerily, I began my career with the NWS working part time early in 1974 when the April 3rd, 1974 Outbreak occurred and retired just days before the April 27th, 2011 Outbreak, that superseded it.

 

PALM SUNDAY TORNADO OUTBREAK
APRIL 11TH, 1965

Written by: William R. Deedler, Weather Historian
March, 2005,2012,2015

The Palm Sunday Tornado Outbreak occurred on April 11th, 1965 with the violent storms tearing through much of the Southern Great Lakes Region and Northern Ohio Valley. The worst hit states were Michigan, Indiana and Ohio. It is the third biggest tornado outbreak on record; 47 confirmed tornadoes resulted in 271 people killed and 3,400 people injured in just a twelve hour span. Damages from the storms mounted to more than 200 million dollars (1.5 billion/2015 dollars). Only the "Super Outbreaks" of April 3rd, 1974 and April 27th, 2011 were worse. This write-up is mainly from a Southeast Lower Michigan perspective with some data taken directly from the NWS Storm Data files.

COLD MARCH LION PROCEEDS PALM SUNDAY STORMS

March of 1965 had been a cold and stormy spring month (several degrees below normal, ranking in the top twenty listings for coldest and snowiest Marches at some locations) in Southeast Lower Michigan with several rounds of heavy rain and snow which lasted into early April. There really had been no surge of warm spring weather to speak of that year until the first week of April, the week which preceded the second biggest tornado outbreak in recorded history. During that first week of April, temperatures surged quickly up to near 70 degrees on the 6th but then, just as quickly, they were knocked back down into the 40s again by yet another chilly air mass on the 8th. Palm Sunday weekend (10-11th) started out calm enough with temperatures actually rising up to near normal levels (mid 50s) under partly sunny skies on Saturday. Many meteorologist eyes, however, were focused on the strong mid and upper level jet stream surging across the Southern Plains into the Midwest later Saturday. In retrospect, this was the harbinger of the rough times that lay ahead, the vicious Palm Sunday Tornado outbreak.

PALM SUNDAY

The strong jet core extended throughout all levels of the atmosphere as of Palm Sunday morning. At 850 MB (5000 FT), a 50 to 60 knot west southwest wind could be found over the Southern Plains moving through Kansas into Missouri, while at the 700 MB (10,000 FT) level, a 70 knot wind maximum was surging northeast across the Texas Panhandle into Oklahoma. Higher up, from the 500 MB to 300 MB (18,000 - 30,000 FT) layer, incredibly strong maximum winds of 120-150 knots extended from the Desert Southwest into the Southern Plains.



At the same time, and in response to the strengthening upper level winds, a deepening surface low pressure system was taking shape over the Midwest. This intensifying low pressure, central pressure at 990 MB (or about 29.20") moved east northeast into Iowa by the forenoon hours of Palm Sunday. Its attending warm front surged northward into Southern Indiana and Ohio, while the 850 MB warm front pushed north into Southern Lower Michigan. As this warmer, more unstable air aloft approached Southern Lower Michigan, scattered thunderstorms were triggered during the pre-dawn hours. A thunderstorm was ongoing at both Detroit City and Metropolitan airports as of the 400 AM EST observation (Detroit City Airport was the official climate observing site for Detroit at the time and this was transferred to Metro Airport just a year later in April 1966).


Temperatures climbed up through the 40s over Southern Lower Michigan during the forenoon hours of Sunday, while behind the warm front (along the Ohio River), readings rose into the mid 70s and were accompanied by dew points in the lower to mid 60s. Early in the day, the surface warm front surged rapidly northeast, aided by the strong south winds of 20 to 30 mph at the surface (and as mentioned earlier, much stronger aloft). During the early afternoon hours, the warm front pushed northeast into extreme Southeast Lower Michigan. With the passage of the front, skies broke out which allowed some sunshine to aid in raising the temperatures into the mid 60s to lower 70s by mid afternoon. Dew points followed right along for the ride, rising from the lower 40s early in the day, to the lower 60s by mid afternoon. This helped set the stage for the violent weather that was to explode shortly over the Lower Great Lakes and Northern Ohio Valley. 



The deepening low pressure system and attending fronts began spawning severe thunderstorms and tornadoes over Eastern Iowa, Extreme Southern Wisconsin and Extreme Northern Illinois early that Palm Sunday afternoon. Along with numerous severe thunderstorms, up to 13 major tornadoes swirled violently through that region. As the low pressure center pushed east northeast across Central Wisconsin, the strong jet core of upper winds began to surge northeast into the Lower Great Lakes Region. Severe thunderstorms blossomed out ahead of the swiftly moving cold front, which extended in an arc from the greater Chicago area south southeast across extreme western Indiana along the instability axis. The first tornadoes spawned in the tri-state area (Michigan-Indiana-Ohio) developed quickly and in rapid succession over Extreme Northern Indiana (see map of tornado tracks) starting 545 PM EST, then 613 PM, 618 PM, another at 625 PM and on and on.


It was also just about this time that severe thunderstorms moved onshore into Western Lower Michigan from Lake Michigan. The storms extended from Muskegon southward to the Holland area. At 630 PM EST, one tornado (F3) touched down in Kalamazoo County, while another tornado (F4) developed at 650 PM EST and moved across Ottawa and Kent counties. Still, another complex of severe storms ignited more strong tornadoes over Central Indiana, starting just after 6 PM EST.

CLOSER TO HOME: TERRIBLE TWOS

Detroit Radar (per NWS/DTW right; Fujita et al. MWR, 1970) showed a rapid increase in thunderstorms over West Central and Southwest Lower Michigan and Northern Indiana by late afternoon. Storm movement was pegged east northeast at around 70 mph! As these storms roared into South-Central Lower Michigan, two horrible twisters were spawned over Branch County, one at East Gilead at 715 PM EST and the other, just a half hour later, southwest of Kinderhook (or, nearly in the same spot as the first). The first tornado seemed to be the most intense and may have caused the most deaths. After striking East Gilead, the storm tracked across Coldwater Lake and damaged several homes along its path. It was about this time (1/2 hour later) that the second twister took off, also plowing across Branch County in nearly the same path as the first. Branch County was hardest hit with at least 19 people killed and about 200 injured, with just under 200 homes destroyed and $20 million (149 million/2015 dollars) in damages.


The tornadoes then sped quickly across Hillsdale County, both tracking just south of the town of Hillsdale. So identical where the tornado paths at this point, that the second tornado actually leveled much of the remaining standing parts of homes hit by the first tornado! At least 11 people were killed in Hillsdale County by these storms along with at least $7 million (52 million/2015 dollars) in damages, including the 177 homes leveled. As the tornadoes crossed into Lenawee County, about 100 vacation homes (cottages) were torn apart on Devil's Lake at Manitou Beach but fortunately, being early April, most were vacant at the time. However, just south of Manitou Beach, the Manitou Beach Baptist Church was destroyed, burying 26 people alive under its debris. Miraculously, only one man died later from his injuries sustained at the church. Five miles south of Manitou Beach, a family in a home did not fare as well with six members of the family perishing in the storm!

The damage path from these terrible two tornadoes extended at one point up to four miles wide, though some of this damage might well have been also due to straight line winds. At least 14 people were killed in Lenawee County with damages amounting to $5 million (37 million/2015 dollars) and 189 homes destroyed. In the four counties, 44 people were killed along with 612 injured with property damages amounting to around $32 million (238 million/2015 dollars). These tornadoes were ranked an F4 on the Fujita Scale and their total paths were about 90 miles long. The tornadoes dissipated over extreme Northern Monroe County east of Milan. During these two monsters lives, over a thousand (1026) buildings were damaged along with countless vehicles (cars, trucks, boats, etc). With all the destruction that these two tornadoes brought to the area, we were fortunate to capture the wind gusts on a rather resilient wind gust recorder at Tecumseh in Lenawee County.

 
The Palm Sunday Outbreak from a Manitou Beach (Lenawee Co.) perspective
  • By Dan Cherry, author of Night of the Wind: The Palm Sunday Tornado of April 11, 1965

OTHER TORNADO "FAMILY" MEMBERS CAUSE HAVOC IN SOUTHEAST LOWER MICHIGAN

Another F4 tornado touched down at 815 PM EST and roared across Clinton County into Shiawassee. The path of this tornado was about 20 miles long at extended from just south of Dewitt (in Southern Clinton County), east northeast to Bennington (or just southwest of Owosso). A nine-year old girl was killed and six homes were destroyed in Clinton County, while three more homes were destroyed in Shiawassee County.

As 9 PM EST approached, two weaker F2 tornadoes appeared farther north in Bay and Tuscola counties. One tornado touched down at 850 PM EST in Bay County at Portsmouth Township and tore the roofs off some buildings and destroyed a few barns and trailers before moving out over Saginaw Bay. At 9 PM EST, another F2 tornado dropped down out of the sky over Tuscola County; it then moved east northeast for 10 miles ending at the town of Unionville. Some barns and a lumberyard were demolished along the ten mile path. There were no deaths and only two injuries with these two tornadoes.

A final tornado (another killer F4) touched down near the Michigan/Ohio State line (mainly on the north side of Toledo) at approximately 930 PM EST. The storm tracked east northeast and caught the extreme southeast tip of Monroe County. The worst damage from this tornado occurred on the north side of Toledo with 16 people killed in Ohio and two in Michigan. About 50 homes were destroyed along with a bus that was picked up and slammed down on I-75, killing four people. Damages with this tornado amounted to around $25 million (186 million/2015 dollars).

Much of the Detroit Metro Area observed strong to severe thunderstorms with very heavy rainfall as the intense low pressure system and strong cold front surged through Lower Michigan that night. Both Detroit City and Metropolitan Airports received about 1.5 inches of rain, whereas Flint measured just a quarter of an inch (.25). As the system moved into Canada, it put an end to the severe weather (well, almost). Very strong isobaric winds encompassed the region behind the storm center on Monday morning, the 12th, with Detroit City Airport (which at that time, housed the wind gust equipment) clocking a west northwest wind gust at 55 mph!

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

Apr 1, 2015

March Was Pretty Much Cool, Calm and Collected But What About April? And, Are We Done With Snow?

-4/3/15 Quick Update for overnight and Easter:

Occasional light rain will become mixed with and change to snow overnight with any accumulation an inch or less on grassy areas. Easter looks similar especially across the metro Detroit northward in Southeast Lower Michigan. Temperatures will be below normal over the weekend.

--------------

4/1/15

March was a rather unusually calm month over the region with well below normal precipitation and snow along with below normal temperatures. The pattern followed previous analogue patterns discussed in my Spring Outlook and my forecast. March was anticipated to contain below normal temperatures and precipitation.

Temperatures:  Below into mid Spring (March-April)
Snowfall:          Snowfall should end up around normal to above over the
                        southern sections of Southeast Lower Michigan and normal to
                        locally below northern sections for the cold season.

Precipitation:   Normal to below.

That's not to say the month didn't contain some nice spring days but the colder than normal days out did any warmer with readings averaging two to three degrees below normal. This is certainly better than last March when March averaged eight and a half degrees below normal with much more snowfall /12.5"/ at Detroit.
 
Temperatures / Precipitation / Snowfall for March 2015 
DETROIT
Average Mean Temp 34.5/-2.7
Precipitation .80/-1.48
Snowfall 2.8"/-4.7


April's Outlook: Stormy?

Latest model trends and past analogues suggest things are about to become busier across the Great Lakes as the predominant southern storm track lifts northward with the springtime warmth. As like last year; spring has gotten off to a later start across the Great Lakes with the jet stream staying mainly south and subsequently, warmer temperatures and precipitation on average also stayed south. This is not unusual, especially when the latter part of winter was so bitterly cold and the Great Lakes reaching 88% ice covered late February. When we are surrounded by a giant bowl of ice, it's bound to affect low level warmth early spring.

First things first; Upcoming Easter Period

Over the past few weeks; all guidance had been intimating a change late in March into early April in the jet stream and relating surface patterns. Stronger warmer and contrasting cold patterns, very typical of March into April was forecast to finally arrive bringing a stormier pattern that had been lacking in March. This had been on tap to begin with earnest the advent of April including Easter week and weekend. The main issues of course have been what, when and where as with all weather phenomenon.

Thunderstorms? It's been awhile...
 
Look for more spring-like days in the very near term Wednesday and especially, Thursday as a strong warming behind a warm front will push temperatures well into the 60s and possibly lower 70s. Unfortunately, a equally strong cold front will create a band of showers and scattered thunderstorms on Thursday. It's been quite awhile since we had thunderstorms across the region; in fact one has to look back to October! Both Detroit and Flint officially last reported a thunderstorm on October 28th while Saginaw hasn't seen one since October 3rd...all over five months. On average, Southeast Lower Michigan experiences two or three thunderstorm days during that five month cool period.


If you think we are done with snowfall, think again...

Yes, no sooner do we get a better taste of spring and we are slammed with colder air and the risk of snow, measurable snow. Latest indications which has the definite support of climate statistics say no; we aren't done with snow. On the climatological statistical side of things, we average at least a few inches of snow over Southeast Lower Michigan in April. We've had some decent (or indecent depending your point of view) snowstorms in April with the largest ever recorded in Detroit April 6th, 1886 with 24.5". On the model side of things; we may get our chance to get measurable snow Friday night (no, nothing like 1886) and possibly even again, Easter Sunday itself. At this time, Friday night into Saturday morning shows the best chance for snow across Southeast Lower Michigan as a wave of low pressure slides northeast through the upper Ohio Valley, along the cold front that is expected through here early Friday. Some models push it further south however, so it still isn't written in snow. ;-)



I'll update when things look more certain as these times approach for Easter Weekend.

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

Mar 10, 2015

Second Cold Winter is in the Books! So Let's Look at Those Cold Temperature Statistics

Our second cold winter is in the books across Southeast Lower Michigan; so let's look at those cold statistics and compare them to last winter's. In addition, I'll compare the actual temperature statistics of this winter to my Winter Outlook's forecast issued last fall. Some of the things worth noting is that even though this past Winter of 2014-15 did average higher than the Winter of 2013-14; it was still a cold enough winter to land in the top 20 coldest winters list of Southeast Lower Michigan. The bowels of the cold occurred in February which was an incredibly cold month by any winter month standards, placing in the top five spots for coldest Februaries and all time months. It was the second very notable cold February in a row for Southeast Lower Michigan. In addition, by far February was most notable winter month for snowfall. Ironically, last winter it was January that was the most notable for cold and snow. I'll discuss more about the snowfall and storms in an update on the winter after the snow season ends.

Winter 2014-15 Temperature Statistics

Location Winter 2014-15 Coldest Winter Since
2014-15 Ranking All-time Coldest
Detroit
23.0/-4.9
1977-78
18th-T 18.8 (1903-04)
Flint
21.7/-3.3
1978-79 17th 16.7 (1976-77)
Saginaw
21.5/-3.2
1978-79
20th 15.7 (1962-63)

T denotes Winter 2014-15 tied with 1958-59

                                   Winter 2013-14 Temperature Statistics
Location Winter 2013-14 Coldest Winter Since
2013-14 Ranking All-time Coldest
Detroit 20.9 1977-78
8th 18.8 (1903-04)
Flint 19.0 1978-79 5th 16.7 (1976-77)
Saginaw 18.2 1978-79
7th 15.7 (1962-63)

  

Top 20 Coldest/Warmest Februaries in Southeast Lower Michigan
 
Rank Detroit Area* Flint Bishop** Saginaw Area***
Coldest Warmest Coldest Warmest Coldest Warmest
Temp Year Temp Year Temp Year Temp Year Temp Year Temp Year
1 12.2 1875 39.5 1882 11.3 2015 34.5 1998 11.5 2015 33.4 1998
2 14.1 2015 36.7 1998 12.8 1979 31.8 1983 12.1 1979 31.5 1984
3 14.8 1934 33.8 1930 13.4 1978 31.2 1984 13.0 1914 30.7 1932
4 16.0 1936 33.6 1877 14.9 1963 31.1 1930 13.2 1963 30.7 1930
5 16.1 1904 33.5 1954 16.0 2014 31.1 1932 13.4 1934 30.6 1931
6 16.3 1978 33.3 1984 16.4 1936 31.1 1927 13.6 1978 30.5 1999
7 16.4 1979 33.3 1976 17.1 1934 31.0 2012 13.6 1936 30.3 2012
8 16.5 1901 33.0 1932 17.3 2007 31.0 1976 14.3 1917 29.9 1954
9 17.2 1885 32.9 2002 18.3 1967 31.0 1931 15.5 2014 29.1 1983
10 17.6 1914 32.8 1931 18.4 1994 30.9 1999 16.8 2007 29.0 1938
11 17.9 1905 32.7 1999 18.5 1923 30.8 1954 16.9 1962 28.9 1976
12 17.9 1895 32.6 2012 18.7 1958 30.1 1938 16.9 1994 28.8 2002
13 18.3 1912 32.6 1890 19.9 1942 30.0 2002 16.9 1912 28.3 2000
14 18.8 1963 32.1 1953 20.0 1962 29.4 1992 17.1 1923 28.2 1921
15 19.3 2007 32.1 1880 20.0 1959 29.3 2000 17.4 1916 28.1 1927
16 19.4 2014 31.8 2000 20.1 1988 29.2 1991 17.8 1920 28.1 1915
17 19.5 1917 31.8 1927 20.2 1982 28.8 1953 18.5 2003 28.0 1991
18 19.8 1899 31.6 1983 20.3 1980 28.7 1987 18.6 1967 28.0 1987
19 19.8 1889 31.2 1991 20.3 1929 28.2 1981 18.9 1958 27.7 1992
20 20.7 1982 31.2 1938 20.5 2003 27.9 1925 18.9 1913 27.7 1937
* Detroit Area temperature records date back to January 1874.
** Flint Bishop temperature records date back to January 1921.
*** Saginaw Area temperature records date back to January 1912.


While the listing of the coldest months has yet to be updated at the NWS to include February 2015, it is easy to see where each site would place with the February temperatures available. Detroit's average of 14.1 would place this past February in fifth place. Flint's average of 11.3 secures a second coldest month placement while Saginaw's reading of 11.5 degrees just jumps ahead of 11.6/Jan 1963 for third place.



Top 20 Coldest/Warmest Months in Southeast Lower Michigan
 
Rank Detroit Area* Flint Bishop** Saginaw Area***
Coldest Warmest Coldest Warmest Coldest Warmest
Temp Year Temp Year Temp Year Temp Year Temp Year Temp Year
1 12.2 Feb-1875 79.0 Jul-1955 10.9 Jan-1977 78.0 Jul-1921 9.4 Jan-1912 77.5 Jul-1921
2 12.8 Jan-1977 79.0 Jul-1921 12.8 Feb-1979 77.7 Jul-1935 10.4 Jan-1918 76.8 Jul-1916
3 13.1 Jan-1912 77.9 Jul-1916 13.1 Jan-1963 76.7 Jul-1934 11.6 Jan-1963 76.2 Jul-1935
4 13.2 Jan-1918 77.7 Jul-1931 13.4 Feb-1978 76.5 Jul-1955 11.7 Feb-1904 76.0 Jul-1931

14.8 Feb-1934 77.1 Aug-1995 13.8 Jan-1994 76.1 Jul-1931 12.1 Jan-1994 75.9 Jul-1955
    5  -  14.1 Feb-2015                     2 - 11.3                              3 - 11.5


Even with considerably less snow than our all out snowy winter of 2013-14; all cities managed to place in the snowiest list for February. Again, more on the snow side of the winter in successive blogs.

Top 20 Snowiest/Snowless Februaries in Southeast Lower Michigan
 
Rank Detroit Area* Flint Bishop** Saginaw Area***
Snowiest Snowless Snowiest Snowless Snowiest Snowless
Total Year Total Year Total Year Total Year Total Year Total Year
1 38.4 1908 0.0 1998 31.7 2011 0.4 1998 34.2 2008 0.0 1987
2 31.7 2011 0.7 1953 29.4 2008 1.4 1992 29.4 2011 0.1 1984
3 28.4 1881 0.9 2004 21.8 2014 2.2 1987 23.4 1935 0.5 1998
4 28.0 1900 1.5 1895 21.2 2010 2.4 1953 22.2 2013 1.4 1983
5 27.6 1926 1.6 1906 20.8 1990 2.4 1937 20.3 1965 1.9 1977
6 27.0 2010 2.0 1987 20.6 1986 2.9 1969 20.0 1912 2.0 1932
7 26.4 2015 2.1 1882 20.1 1994 2.9 1943 19.8 1985 2.1 1980
8 24.2 2008 2.2 1915 19.7 1965 3.0 1979 18.6 1926 2.2 1947
9 23.5 2013 2.3 1969 19.6 1988 3.0 1934 18.4 1990 2.4 1942
10 23.4 2014 2.4 1992 18.3 1946 3.5 1945 18.3 2010 2.5 1969
11 20.8 1986 2.4 1937 17.4 2015 3.6 1984 18.0 2005 2.6 1928
12 19.6 1898 2.5 1966 17.2 1960 3.6 1938 17.7 1924 3.1 1995
13 19.2 2003 2.6 1891 17.0 1924 3.8 1977 17.5 1950 3.2 1919
14 19.2 1988 2.7 1943 16.7 1973 4.1 1928 17.1 1956 3.4 1958
15 18.0 1893 2.8 1968 16.6 2013 4.5 1957 17.0 2014 3.5 1963
16 17.1 1994 2.8 1925 16.5 1926 4.8 1983 17.0 2012 3.7 1957
17 16.9 1985 2.9 2001 16.3 1967 4.9 1932 16.2 2015 3.7 1917
18 16.5 1936 3.1 1949 16.1 1993 5.0 2001 16.2 1962 3.8 1913
19 16.4 1901 3.1 1919 16.1 1962 5.1 1921 16.2 1946 4.0 1964
20 15.8 1965 3.3 1886 15.7 2006 5.3 1958 16.0 1954 4.1 1938
* Detroit Area snowfall records date back to January 1880.
** Flint Bishop snowfall records date back to January 1921.
*** Saginaw Area snowfall records date back to January 1912.


             Best performing analogues with 1884-85 and 1977-78 star performers




My Winter Outlook Call back in November (from Winter Outlook for Southeast Lower Michigan)

Temperatures: Below Normal /-1.0 to -4.0 degrees of the norm/

Temperatures are more variable in this winter's analogues and guidance as opposed to last winter when nearly all headlined a cold winter. That being said, normal to below normal temperatures dominate this winter again in the analogues and is suggested in other meteorological data presented here and why the below normal temperature range of -1 to -4 degrees. The largest below normal departures this winter are projected to be south and southeast of the Great Lakes. In addition; recent past seasons along with very recent unfolding conditions and the subset of preferred analogues also predict  another colder than average winter. Analogue timing of the coldest parts of the winter varies but majority suggest temperatures most likely to be below normal mid and late winter.

Average winter temperature for Southeast Lower Michigan for the winter of 2014-15 using the three climate sites came in at 22.1 which is 3.8 below normal.

All Ten Analogue Composite Map Issued in November 2014



Five Good Call Analogue Composite Map Issued in Nov 2014 for Winter 14-15

(only three years avail for composite, 1884-85 & Dec1894 N/A)



While winter turned out cold in all five winters (looking at my analogues & three winter map), it's interesting how mild or warm the five Decembers were in all five winters (Dec 1884 & 1895 maps N/A) giving more credence to the strong likeness and accurate projections for temperature trends to this past winter.



While both January and February were colder than normal in the East, February definitely was the stand out this year and in the past. Remember, the map below doesn't include February 1885, one of our coldest Februaries in the analogues. The coldest blue anomaly approaches -10.0 normal on average for these four Februaries in the Ohio Valley, Southern Lakes and Northeast while warm weather with above to well above normal anomalies prevailed in the West.


Two Best Call Analogue Composite Maps Issued in November 2014

Unfortunately, only one of the two best analogue maps is available since the winter of 1884-85 is N/A but a great analogue none the less - as was 1977-78. Also as an added  bonus, while not nearly the strength or magnitude of Blizzard of January 26-27, 1978; this past winter also contained quite a notable snowstorm on Feb 1-2nd that brought the third biggest snowstorm amount to Metro Detroit ever (and even more than the aforementioned Blizzard of '78) with 16.7". This storm largely helped consummate the 7th snowiest February on record with 26.4" in Detroit.



More later on other noteworthy items about the Winter of 2014-15, including the final tally of snowfall for the winter.


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














Mar 7, 2015

Early Spring Moderating Trend Finally Arrives This Week

After weeks and weeks of bitter cold and below normal temperatures this year; March will feel like March with a notable moderating (or warming trend if you will) that was expected in my previous blog to finally commence this second week of March. The broad, huge trough of low pressure that was anchored much of the time over the eastern half of Canada and US, will drift far enough east to allow normal to above normal temperatures into the region. Look for temperatures to warm well into the 40s this week to possibly even near 50. I warn you however, this could be a shock to your system after living the life of an Eskimo in February.



Speaking of February; I'll have the winter temperature statistics out shortly and compare them to the best performing analogues.

Enjoy the early spring thaw!

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

Feb 18, 2015

Winter Outlook and Recent Model Trends Converge and Intimate a Cold Ending to the Winter; Part II - Long Term



On my previous blog; I discussed the short term ramifications of the current "Siberian Express" over the Great Lakes and Southeast Lower Michigan. Now lets look ahead a bit into early spring and what my best analogues and current model data suggest for rest of February into March and April. Taking the analogues that have performed good (over all; 5) and the ones that have performed best (2). So, let's see if past meets up with future (models) for this early outlook. The winter of 1884-85 and 1977-78 seem to have the inside track thus far in overall temperatures and snow pattern.

PAST AND PRESENT 

Out of the original ten analogues winter temperatures below /Detroit/; six were below normal, three were normal and just one above. Remember this is guidance based on the past /analogues/ with similar hemispheric conditions in place along with other variables considered such as local previous seasons weather to even similar solar activity. They only suggest or "intimate" how the weather will unfold for the next three months and a not to be used as much for exact temperature departures nor timing. The overall analogue temperature forecast from the original ten has worked out very well thus far this winter in predicting a colder than average winter. In fact; only one of the ten suggested a warmer winter. More on temperatures; looking at the monthly average departures, timing or the temperature trend also worked well. December was most likely to be normal or above with January and February, most likely to be below normal. And, depending on exact timing; February had the best chance to be the most below normal /-3.4/. It's been an rewarding winter in this regard since timing /monthly/ trends are not always the best predictors of "exactly when". The same can be said of magnitude or "exactly how much" in regard to both temperature and snowfall. It is up to me as the forecaster to use the data/guidance chosen and interpret and interpolate from there for a season projection.

Original Ten Analogues for Detroit: Winter of 2014-15


Between temperature and snowfall, snowfall is usually the more vague or chaotic analogue guidance and this winter has been no exception with a split vote on how the winter would play out for amount. Note, there were five above normal snow seasons, four below normal and one near normal. The snow amount consensus averaged on the high side of normal in the original ten /47.2"- Detroit/ for the southern half of lower Michigan. This area basically extends from Flint to Port Huron (or I-69) south to the Ohio border. Further north; normal to below normal amounts were projected. This snow guidance of past analogue winters was also chosen for this winter.

Out of the original ten analogues chosen for the winter; half of them were singled out to be the better to best performing analogues through mid February. These five analogues thus far, have bested either in temperature and/or snowfall amounts, departures or trends when combined. Note that the February departure alone drops to -6.0 from the -3.4 earlier. Out of the five, only one season contained normal temperatures or below normal snow. While 1924-25 is a weaker analogue, it's snowfall trend was still helpful. Most of these five had similar overall weather patterns across the country and East Coast. Monthly snowfall amounts were quite variable in Southeast Lower Michigan, especially when looking at December and January where it seemed it was feast or famine. This of course, is not unlike this winter (December versus February for example). Out of those five; two are the best performing analogues thus far; 1884-85 and 1977-78 for both temperature and snowfall (first and last analogue).

                                     Best Performing Analogues Thus Far




As of mid February /17th/; Detroit's average temperature is 17.2, or within range of both  February's in 1885 /17.2/ and 1978 /16.3/. Latest indications for the remainder of February is bleak if you are looking for milder weather. It really doesn't look like any major warming trend is in sight this month. As stated in the first section; I looked for this past week to be the worst of the winter weather and now February, to be the worst month of the winter when combining both cold and snow. So much so, it may even give January 2014 competition for its frigid mean temperature /16.4/! That would be something but we'll have to wait and see on that one. In addition; up through 2/17; 42.5" of snow has fallen at Detroit Metro Arpt and I expect snowfall to be normal or better from here on out which would add at least another foot and half of snow. This would bring the winter's total near the 1884-85 /60.8"/ and 1977-78 /61.7"/snowfall totals.

Interestingly; some analogue years with less snow /1923-24 &1939-40/ did the best up until February with a mild December, cold January and below normal snow. In fact by late January; 1939-40 looked to be the best - 'ah but winter was not over yet! The truer, facsimile of this winter would be reveled later as time rolled on. Trends in the analogues were for the worst of the winter, cold and snow combined, to be "back-end loaded" and stated as such in my original Outlook. I feel these five analogue winters are similar to the present day meteorological models in a sense; where all can have similar trends but generally, only one or two is the champ. Overall, when taking both temperatures and snowfall into account, the worst of the winter was expected mid-late season - and this has certainly been the case in February. However; it would be remiss of me not to mention that early indications are for moderating trend after the turn of the month in early March


Future

So that's past and present; what about further in the future? Keeping one eye on the analogues and the other on current long term models into spring does not hold much promise for an warm spring. Keep in mind, this early-mid spring outlook is based on the best performing analogues thus far this winter and model preferences. We'll revisit this again when more data is available early in the spring if views change. While I feel the worst of the spring analogues may be too cold /42.4-3rd Coldest/, I still look for temperatures to average below normal. Only one spring in the five analogues in the chart below ended up normal but even that still contained a cold March. Overall; the data is not pretty with many of the Marches in the top 20 coldest along with three of the springs in the top 20 coldest. In fact; there was no warm Marches in the five analogues with a compounded average temperature at 29.5 or 7.7 below normal. April improves some but still averages 3.1 degrees below normal; finally later spring /May/ shows some promise closer to normal. This overall pattern is very similar to last year's spring. As with any temperature predictions; the timing issue could play havoc on the spring temperature trend which would negate somewhat the dominant trends seen here.

Ironically, this local spring analogue data also reflects what the latest CFSv2 model data paints for the region. Precipitation trends also are agreed upon by the model with drier conditions painted for the Lakes Region with precipitation on the analogues averages about an inch below normal.
 
Temperatures:  Below into mid Spring (March-April)

Snowfall:          Snowfall should end up around normal to above over the
                        southern sections of Southeast Lower Michigan and normal to
                        locally below northern sections.

Precipitation:   Normal to below.













                                                    
                                                                                                                              Precipitation Outlook






























































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