Climate Zones

It is 5am here at the Weather Center in Otsego – haven’t had a chance to get the ‘official’ precipitation readings yet as the liquid is frozen in my rain gauge.  It is hard to say how much snow we had here as it was mostly a cold rain most of the day with some fat snow flakes and ice pellets mixed in.  We do have a light accumulation on the ground though nothing like what fell north of Allegan/Barry county.

A band of 7-10″ of “concrete” snow (0.8- 1.0″ of liquid equivalent) fell from around Muskegon to Clare, leading to downed tree limbs and thousands of homes and businesses without power.  Yesterday featured the 5th highest snowfall for any April calendar day in Muskegon, with record daily snowfall being observed in Grand Rapids and Muskegon.

Today may be the best day of the week for outdoor activities as our weather pattern will become active once again through most of the rest of the week.


Climate Zones

We now continue with our Met. classes – hope you aren’t getting bored with them yet…..

The earth’s tilt, rotation and land/sea distribution affect the global weather patterns we observe. While the weather varies from day-to-day at any particular location, over the years, the same type of weather will reoccur. The reoccurring “average weather” found in any particular place is called climate.

German climatologist and amateur botanist Wladimir Köppen (1846-1940) divided the world’s climates into categories based upon general temperature profile related to latitude. He worked with Rudolf Geiger to to modify these categories which is know today as the Köppen-Geiger climate classification system The major categories are as follows:

 

A – Tropical Climates
Tropical moist climates extend north and south from the equator to about 15° to 25° latitude. In these climates all months have average temperatures greater than 64°F (18°C) and annual precipitation greater than 59″.

 

B – Dry Climates
The most obvious climatic feature of this climate is that potential evaporation and transpiration exceed precipitation. These climates extend from 20°-35° North and South of the equator and in large continental regions of the mid-latitudes often surrounded by mountains.

 

C – Moist Subtropical Mid-Latitude Climates
This climate generally has warm and humid summers with mild winters. Its extent is from 30°50° of latitude mainly on the eastern and western borders of most continents. During the winter, the main weather feature is the mid-latitude cyclone. Convective thunderstorms dominate summer months.

 

D – Moist Continental Mid-latitude Climates
Moist continental mid-latitude climates have warm to cool summers and cold winters. The location of these climates is poleward of the “C” climates. The average temperature of the warmest month is greater than 50°F (10°C), while the coldest month is less than -22°F (-30°C). Winters are severe with snowstorms, strong winds, and bitter cold from Continental Polar or Arctic air masses.

 

E – Polar Climates
Polar climates have year-round cold temperatures with the warmest month less than 50°F (10°C). Polar climates are found on the northern coastal areas of North America, Europe, Asia, and on the land masses of Greenland and Antarctica.

 

H – Highlands
Unique climates based on their elevation. Highland climates occur in mountainous terrain where rapid elevation changes cause rapid climatic changes over short distances.

The map (below) shows where these major categories occur in the mainland United States.

The major Köppen zones in the U.S.


Köppen and Geiger further divided each major divisions (A, B, C, D, E, F, H) into smaller groups based upon precipitation and temperature patterns. These subcategories are as follows:

Second letter add additional divisions based on precipitation pattern

  • f – wet year-round
  • s – dry summer season
  • w – dry winter season
  • m – monsoon

Third letter (lower case) add additional divisions based in temperature pattern

  • a – hot summer
  • b – warm summer
  • c – cool summer
  • d – very cold winters
Köppen-Geiger climate classification. From Kottek, M., J. Grieser, C. Beck, B. Rudolf, and F. Rubel, 2006: World Map of the Köppen-Geiger climate classification updated. Meteorol. Z., 15, 259-263.

Af Equatorial rainforest No dry season. The driest month has at least 2.36″ (60 mm) of rain. Rainfall is generally evenly distributed throughout the year. All average monthly temperatures are greater than 64°F (18°C).
Am Equatorial monsoon Pronounced wet season. Short dry season. There are one or more months with less than 2.36″ (60 mm). All average monthly temperatures are greater than 64°F (18°C). Highest annual temperature occurs just prior to the rainy season.
As Equatorial savanna Summer dry season. There are more than two months with less than 2.36″ (60 mm) in summer. All average monthly temperatures are greater than 64°F (18°C).
Aw Equatorial savanna Winter dry season. There are more than two months with less than 2.36″ (60 mm) in winter. All average monthly temperatures are greater than 64°F (18°C).
BWk Mid-latitude desert Mid-latitude desert. Evaporation exceeds precipitation on average but is less than half potential evaporation. Average temperature is less than 64°F (18°C). Winter has below freezing temperatures.
BWh Subtropical desert Low-latitude desert. Evaporation exceeds precipitation on average but is less than half potential evaporation. Average temperature is more than 64°F (18°C). Frost is absent or infrequent.
BSk Mid-latitude steppe Mid-latitude dry. Evaporation exceeds precipitation on average but is less than potential evaporation. Average temperature is less than 64°F (18°C).
BSh Subtropical steppe Low-latitude dry. Evaporation exceeds precipitation on average but is less than potential evaporation. Average temperature is more than 64°F (18°C).
Cfa Humid subtropical Mild with no dry season, hot summer. Average temperature of warmest months are over 72°F (22°C). Average temperature of coldest month is under 64°F (18°C). Year around rainfall but highly variable.
Cfb Marine west coast Mild with no dry season, warm summer. Average temperature of all months is lower than 72°F (22°C). At least four months with average temperatures over 50°F (10°C). Year around equally spread rainfall.
Cfc Marine west coast Mild with no dry season, cool summer. Average temperature of all months is lower than 72°F (22°C). There are one to three months with average temperatures over 50°F (10°C). Year around equally spread rainfall.
Csa Mediterranean Mild with dry, hot summer. Warmest month has average temperature more than 72°F (22°C). At least four months with average temperatures over 50°F (10°C). Frost danger in winter. At least three times as much precipitation during wettest winter months as in the driest summer month.
Csb Mediterranean Mild with cool, dry summer. No month with average temperature of warmest months are over 72°F (22°C). At least four months with average temperatures over 50°F (10°C). Frost danger in winter. At least three times as much precipitation during wettest winter months as in the driest summer month.
Cwa Humid subtropical Mild with dry winter, hot summer
Dfa Humid continental Humid with hot summer
Dfb Humid continental Humid with severe winter, no dry season, warm summer
Dfc Subarctic Severe winter, no dry season, cool summer
Dfd Subarctic Severe, very cold winter, no dry season, cool summer
Dwa Humid continental Humid with severe, dry winter, hot summer
Dwb Humid continental Humid with severe, dry winter, warm summer
Dwc Subarctic Severe, dry winter, cool summer
Dwd Subarctic Severe, very cold and dry winter, cool summer
ET Tundra Polar tundra, no true summer
EF Ice Cap Perennial ice
H Complex zone Can encompass any of the above classifications due to the mountainous terrain.

 

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Mark (East Lansing)Rocky (Rockford)INDYMr. NegativeBarry in Zeeland Recent comment authors
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Rocky (Rockford)
Rocky (Rockford)

Golf weather this week looks lousy unless you enjoy playing in the rain on a soggy course!

Mark (East Lansing)
Mark (East Lansing)

Our course was busy today.

Andy W
Andy W

Rocky would not know, he was out snowshoeing in soggy muddy slop today! For some reason he can snowshoe and ski in the worst conditions imaginable (sloppy man made slush snow or on 1 inch of regular snow or in 20 degrees below zero weather with 50 mph winds) but he can only golf if conditions are picture perfect with no clouds in the sky and 70 degrees!

Rocky (Rockford)
Rocky (Rockford)

Too funny because we had inches snow cover on the course over here!

Rocky (Rockford)
Rocky (Rockford)

What a snowstorm and what a great winter for skiing! After all it is mid April so maybe just maybe the snow is done and I can switch to golf! Ideal golf weather for me is temps in the 70’s with light wind, so it will probably take another rmonth for real golf weather! Incredible!

Andy W
Andy W

So wonderful to see Spring back in the air today with all that beautiful green grass!! Winter’s miserable torment tried to make a brief appearance but SPRING dominated it today and sent Winter back to hell where it belongs until December!! BRING ON THE 60’s and 70’s!!! We’re all ready!! BEST TIME OF THE YEAR!!

Mookie
Mookie

The CPC shows nothing but above average temps too!

Andy W
Andy W

Some magnificent weather coming up that will be far more enjoyable for outdoor activities!

https://weather.com/weather/tenday/l/USMI0344:1:US

Mark (East Lansing)
Mark (East Lansing)

Perennials are up and the trees are budding. Birds are all kinds of noisy at sunrise. I love this time of year too.

Rocky (Rockford)
Rocky (Rockford)

What an absolutely EPIC April snowstorm! It looks like the models were correct despite Andy and his incessant comments about fake news and the models are never correct! The models consistently showed 4 to 10 inches And Bingo! The snowshoeing was also epic this AM! Incredible!

https://www.weather.gov/grr/weatherstory

Andy W
Andy W

I love your snow models now!! Especially this one, I’m surprised you haven’t posted it yet!

http://wxcaster.com/gis-snow-overlays2.php?STATIONID=GRR

Mookie
Mookie

Lol epic melting I’d say!

Andy W
Andy W

Heck yeah Mookie, fastest I’ve ever seen snow melt!! LOVE IT!!

Andy W
Andy W
Rocky (Rockford)
Rocky (Rockford)

You two are a trip! Get a grip!

Slim

Well my time on jury duty did not last very long. I did get to go to the 11th floor and I was picked to sit in juror seat #3 I was asked questions by the judge and the prosecutor attorney none by the defense attorney. Several we removed for cause by the Judge and one by the prosecutor and none (for cause) by the defense. Then out of the blue I was removed by the defense. Oh well that the way the ball bounces.
Slim

Barry in Zeeland
Barry in Zeeland

I had the same thing for 1 case. I was drawn to be on the jury, but then replaced. I was so jacked up to get in, then bummed when I was dismissed.

INDY
INDY

Jury duty is a headache for working people .Gone Twice would of rather been at work..INDY

Barry in Zeeland
Barry in Zeeland

Not when you get paid for being there and paid from work. Like a vacation with real life law and order.

Mookie
Mookie

Exactly how I feel, Barry! Plus, you’re serving your community.

INDY
INDY

Hey slim now that the sun is out and April is half over spring has finally started it’s safe to say like in the land of the munchkins Wizard of Oz come out come where ever you are …lol! INDY!

Mr. Negative
Mr. Negative

Jury Duty is only for a select few. Maybe 5,000 of the same people, are continually drawn over and over again, across the country. My father was called 11 times over his life. No other person in our entire family tree has ever been called. A useless system at best.

Michigan’s climate rating?…ET obviously.

It’s a frigid 71 in Clearwater this morning 🙁

Mookie
Mookie

71 degrees already this morning you say? Wow! haha

By the way, I love the process of jury duty and am always excited when I get called. A paid day off work plus jury pay all while watching an interesting trial and helping serve your community? What could be better!

Mookie
Mookie

GR is still above average temps for April. And that’s before our next big warm up. How can that be?

INDY
INDY

Im going to add a few more thoughts to Slim’s post and and finally give the snow talk a rest for awhile because I’m thinking the next time we see any snow will be in November now Our lovely snow is done… Yesterday marks 6 consecutive months of snow fall records broke for April standards over the 80 inches of snow for winter season in GR many expensive Winter storms Polar vortex we have not felt in over 10 years many places in the upper peninsula over 350 inches of snow record missed school days state of emergency’s declared yes… Read more »

Barry in Zeeland
Barry in Zeeland

And don’t forget the record we set for the least amount of snow ever for the first 50 days of Winter! Who can forget going through our 2 snowiest months measuring snow by tenths of an inch? Our actual “Winter” weather time keeps getting shorter each year!

Mookie
Mookie

Love those short winters! I will gladly take snow anytime that melts almost as soon as it falls!

Mookie
Mookie

A week ago WOOD had this coming Thursday in the low 40’s. Their current forecast? 70 degrees! Get ready for more warmth!

Rocky (Rockford)
Rocky (Rockford)

What a great winter storm yesterday! I will be heading out to the snowshoe trail this am! What a glorious, bueatiful, incredible, spectacular, unbelievable morning! We picked up 6 inches of snow and GR set a record and now we above normal for April and the yearly total is way above normal! Wow that was a nice way to cap off a great El Niño winter with cold and snow galore!!!!

Andy W
Andy W

Well we picked up 32 inches just west of you yesterday so you missed out!

Andy W
Andy W

Yep and now the melt begins and spring can continue as normal now.

Slim

I am up early getting ready to report for jury duty. Very good information today MV (as always). Here at my house I now have 4.4″ of snow on the ground. Officially at Grand Rapids the total at the airport was 4.1″ and over at Muskegon it was 6.7″ and yes they were both records for the dated. Here at Grand Rapids the total season snow fall for the 2018/19 season is now at 81.2″ This above the average of 74.5″ So yes this has been a snowy cold season no matter what several of our blogers want to claim.… Read more »

Rocky (Rockford)
Rocky (Rockford)

Thanks for the facts and the realization that it was a cold and snowy winter season. Yes it was back located but wow! You Rock Slim!

Mark(East Lansing)
Mark(East Lansing)

Good luck. If you do get chosen, hopefully you have an interesting case.