Okay class it is time for another weather lesson, this week we are looking at synoptic meteorology.
The word synoptic means “view together” or “view at a common point”. Therefore, synoptic meteorology is primarily concerned with viewing the weather at a common point — time.
Also known as large scale or cyclonic scale, the size of weather patterns we are looking at range upwards from about 620 miles (1,000 kilometers) across to about 1,500 miles (2,500 kilometers).
When different parameters of the earth’s atmosphere are viewed together at the synoptic scale then large-scale weather patterns emerge, such as extratropical cyclones and their associated fronts.
But before this map will provide any relevant information, one of the primary things a good meteorologist will check is the “time” these various weather elements were observed. We will begin by learning about synoptic times displayed on weather maps and text products issued by the National Weather Service.
Z-time (Coordinated Universal Time)
All aspects of meteorology are based upon a world-wide 24-hour clock called Zulu time (Z), more commonly called Coordinated Universal Time (UTC). You will notice all weather maps, radar, and satellite images all have their time expressed in “Z”. The Zulu term stems from military usage while Coordinated Universal Time is the civilian term for this 24-hour clock.
The origin of these time zones began in the mid 1800’s in England. In 1852 the Royal Observatory in Greenwich, England began transmitting time telegraphically and just three years later became the standard time in most of Great Britain. Also, charts and maps were made with reference to the observatory as the “zero” or prime meridian.
Over the next few decades a number of locations around the world had developed their own meridians as reference points. The Greenwich meridian was the most popular of these in part due to the reputation for reliability and correctness of the Greenwich Observatory’s publications of navigational data.
In 1884, a conference in Washington, D.C. settled the matter where it was agreed to establish a single “prime” meridian (0° longitude), passing through Greenwich. This was for both for longitude and timekeeping. This 0° meridian divides the Eastern from the Western Hemisphere. Today, one can visit the Royal Observatory and straddle this 0° meridian with one foot in each hemisphere.
With the 360° daily rotation of the earth, the sun is moving 15° each hour which leads to the formation of 24 time zones. However, today the individual zone boundaries are no longer straight, nor are they always continuous, as they have been modified for convenience and to satisfy the desires of sovereign nations.
Time zone offsets are identified as -12 UTC through 0 to +12 UTC with the minus values signifying time “before” or ahead of prime meridian (which is the Western Hemisphere). At the meeting of the -12 and +12 time zones is the International Date Line.
Moving west across the International Date Line one moves from the -12 UTC time zone to the +12 UTC time zone. This means you advance the clock 24 hours; in essence you advance one day on the calendar. Moving east across the International Date Line means subtracting 24 hours from the clock thereby reversing one day on the calendar.
The 24-hour clock (Z-time) begins at midnight (00Z) at this prime meridian. 00Z for the United States begins in the evening local time. Z-time does not change with the change for daylight saving time but the local time will change. For example, 00Z in the Central STANDARD Time is at 6:00 p.m. but 00Z occurs at 7:00 p.m. in Central DAYLIGHT SAVING Time.
The following tables show z-times for each time zone in the United States and U.S. Territories.
Z-time | Guam (+10) |
Hawaii (-10) |
Alaska (-9) |
Pacific (-8) |
Mountain (-7) |
Central (-6) |
Eastern (-5) |
Atlantic (-4) |
---|---|---|---|---|---|---|---|---|
00z | 10 a.m. | 2 p.m.* | 3 p.m.* | 4 p.m.* | 5 p.m.* | 6 p.m.* | 7 p.m.* | 8 p.m.* |
01z | 11 a.m. | 3 p.m.* | 4 p.m.* | 5 p.m.* | 6 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* |
02z | 12 noon | 4 p.m.* | 5 p.m.* | 6 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* |
03z | 1 p.m. | 5 p.m.* | 6 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* |
04z | 2 p.m. | 6 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid |
05z | 3 p.m. | 7 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid | 1 a.m. |
06z | 4 p.m. | 8 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid | 1 a.m. | 2 a.m. |
07z | 5 p.m. | 9 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid | 1 a.m. | 2 a.m. | 3 a.m. |
08z | 6 p.m. | 10 p.m.* | 11 p.m.* | 12 mid | 1 a.m. | 2 a.m. | 3 a.m. | 4 a.m. |
09z | 7 p.m. | 11 p.m.* | 12 mid | 1 a.m. | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. |
10z | 8 p.m. | 12 mid | 1 a.m. | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. | 6 a.m. |
11z | 9 p.m. | 1 a.m. | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. | 6 a.m. | 7 a.m. |
12z | 10 p.m. | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. | 6 a.m. | 7 a.m. | 8 a.m. |
13z | 11 p.m. | 3 a.m. | 4 a.m. | 5 a.m. | 6 a.m. | 7 a.m. | 8 a.m. | 9 a.m. |
14z | 12 mid | 4 a.m. | 5 a.m. | 6 a.m. | 7 a.m. | 8 a.m. | 9 a.m. | 10 a.m. |
15z | 1 a.m.# | 5 a.m. | 6 a.m. | 7 a.m. | 8 a.m. | 9 a.m. | 10 a.m. | 11 a.m. |
16z | 2 a.m.# | 6 a.m. | 7 a.m. | 8 a.m. | 9 a.m. | 10 a.m. | 11 a.m. | 12 noon |
17z | 3 a.m.# | 7 a.m. | 8 a.m. | 9 a.m. | 10 a.m. | 11 a.m. | 12 noon | 1 p.m. |
18z | 4 a.m.# | 8 a.m. | 9 a.m. | 10 a.m. | 11 a.m. | 12 noon | 1 p.m. | 2 p.m. |
19z | 5 a.m.# | 9 a.m. | 10 a.m. | 11 a.m. | 12 noon | 1 p.m. | 2 p.m. | 3 p.m. |
20z | 6 a.m.# | 10 a.m. | 11 a.m. | 12 noon | 1 p.m. | 2 p.m. | 3 p.m. | 4 p.m. |
21z | 7 a.m.# | 11 a.m. | 12 noon | 1 p.m. | 2 p.m. | 3 p.m. | 4 p.m. | 5 p.m. |
22z | 8 a.m.# | 12 noon | 1 p.m. | 2 p.m. | 3 p.m. | 4 p.m. | 5 p.m. | 6 p.m. |
23z | 9 a.m.# | 1 p.m. | 2 p.m. | 3 p.m. | 4 p.m. | 5 p.m. | 6 p.m. | 7 p.m. |
Note: *The previous day #The next day |
Z-time | Guam (+10) |
Hawaii (-10) |
Alaska (-8) |
Pacific (-7) |
Mountain (-6) |
Central (-5) |
Eastern (-4) |
Atlantic (-3) |
---|---|---|---|---|---|---|---|---|
00z | 10 a.m. | 2 p.m.* | 4 p.m.* | 5 p.m.* | 6 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* |
01z | 11 a.m. | 3 p.m.* | 5 p.m.* | 6 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* |
02z | 12 noon | 4 p.m.* | 6 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* |
03z | 1 p.m. | 5 p.m.* | 7 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid |
04z | 2 p.m. | 6 p.m.* | 8 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid | 1 a.m. |
05z | 3 p.m. | 7 p.m.* | 9 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid | 1 a.m. | 2 a.m. |
06z | 4 p.m. | 8 p.m.* | 10 p.m.* | 11 p.m.* | 12 mid | 1 a.m. | 2 a.m. | 3 a.m. |
07z | 5 p.m. | 9 p.m.* | 11 p.m.* | 12 mid | 1 a.m. | 2 a.m. | 3 a.m. | 4 a.m. |
08z | 6 p.m. | 10 p.m.* | 12 mid | 1 a.m. | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. |
09z | 7 p.m. | 11 p.m.* | 1 a.m. | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. | 6 a.m. |
10z | 8 p.m. | 12 mid | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. | 6 a.m. | 7 a.m. |
11z | 9 p.m. | 2 a.m. | 3 a.m. | 4 a.m. | 5 a.m. | 6 a.m. | 7 a.m. | 8 a.m. |
12z | 10 p.m. | 2 a.m. | 4 a.m. | 5 a.m. | 6 a.m. | 7 a.m. | 8 a.m. | 9 a.m. |
13z | 11 p.m. | 3 a.m. | 5 a.m. | 6 a.m. | 7 a.m. | 8 a.m. | 9 a.m. | 10 a.m. |
14z | 12 mid | 4 a.m. | 6 a.m. | 7 a.m. | 8 a.m. | 9 a.m. | 10 a.m. | 11 a.m. |
15z | 1 a.m.# | 5 a.m. | 7 a.m. | 8 a.m. | 9 a.m. | 10 a.m. | 11 a.m. | 12 noon |
16z | 2 a.m.# | 6 a.m. | 8 a.m. | 9 a.m. | 10 a.m. | 11 a.m. | 12 noon | 1 p.m. |
17z | 3 a.m.# | 7 a.m. | 9 a.m. | 10 a.m. | 11 a.m. | 12 noon | 1 p.m. | 2 p.m. |
18z | 4 a.m.# | 8 a.m. | 10 a.m. | 11 a.m. | 12 noon | 1 p.m. | 2 p.m. | 3 p.m. |
19z | 5 a.m.# | 9 a.m. | 11 a.m. | 12 noon | 1 p.m. | 2 p.m. | 3 p.m. | 4 p.m. |
20z | 6 a.m.# | 10 a.m. | 12 noon | 1 p.m. | 2 p.m. | 3 p.m. | 4 p.m. | 5 p.m. |
21z | 7 a.m.# | 11 a.m. | 1 p.m. | 2 p.m. | 3 p.m. | 4 p.m. | 5 p.m. | 6 p.m. |
22z | 8 a.m.# | 12 noon | 2 p.m. | 3 p.m. | 4 p.m. | 5 p.m. | 6 p.m. | 7 p.m. |
23z | 9 a.m.# | 1 p.m. | 3 p.m. | 4 p.m. | 5 p.m. | 6 p.m. | 7 p.m. | 8 p.m. |
Note: *The previous day #The next day |
Regardless which National Weather Service weather map, radar, or satellite picture you view, be sure to first check the time of the image as it will be reported in 24-hour “Z” time.
Enjoy today – though it will be relatively cloudy we should stay dry with temps in the mid 50s – this may be the best day of the week before temps drop off and we move into another period of unsettled weather for SW Michigan. By Friday we will struggle to make it to 40° and we have chances of rain mixing with a few wet snowflakes from Tuesday night on through the rest of the week with little or no snow accumulation….
Currently 50* degrees and getting dark out at thee YARDofBRICKS NE GR lots of people coming in my work tonight with winter coats and hats on Love it…Slim Rocky MV any thoughts on the Halloween storm MODELS are all over the place GFS shows pretty good snows falling Friday it’s going to be nasty ..INDY..
49 here at my house, For Halloween I would hope we have a better handle on the system tomorrow.
Slim
I have been looking at MODELS for about a week now lots of agreement on a storm every run moves it a little further east with colder air over west Michigan …They should cancel Halloween .. INDY
Winter weather advisory for the western upper peninsula for 2-4 inches of snow here we go ….Best time of the year is near ….INDY
Don’t let your kids hear you say that. LOL!!
8 day has all 40s and no 30s for highs .. Were do some get there information .. Lol
Enjoy today’s low 50’s maybe the last time for awhile …30’s and 40″s become the norm around here more below average temps love it! INDY
Low 50’s? Where do you get your temps from? We hit 60 here,GR hit 59, Kalamazoo hit 62.
Indeed Barry, it was 60 here today .. Nice try to some trying to spin the temps once again .. Lol ..
Love it well below normal sorry warm weather deuces ..INDY
Why do you keep making things up? Normal high for today is 56 and it was 59. You’re saying 59 is below normal? Wow.
Looks like Holland, Muskegon and Fremont were all in the low 50’s so there must have been a sharp cut off from them low 60’s to lower 50’s
Slim
I just checked the high here at my house was 56. and the low here was 34 it is unusual for the airport to have a warmer high then here at my house.
Slim
It was a good day outside for wrapping up Fall chores.
As they become are posted I like to toss up the winter outlooks from time to time. The one from John Dee just came out today and here it is.
http://johndee.com/seasonalfcst/2019-20/seasonalforecast.htm
As I have said the best starting point is “average”
Slim
His analysis is interesting and not what I was expecting. He is showing more snow west of us and near normal for us. Most of the other sites have us in colder than normal and more snow! Here is hoping for tons of snow and snowstorms! Bring it!
One issue I have for this winter is that so far most of the lows have been either almost over head or to the west of Michigan and that could put Michigan in the warmer sections this winter. We shall see.
Slim
We can’t forget the lk effect zone we could get servel more inches from this winter Season …INDY
If we’re on the warm side of the lows the lake effect won’t be anywhere around here.
In looking at the long range guess models so far this fall I have noticed that on the updated GFS there seems to be less of the big phantom storms in the very long range guess. (5 to 10 days out) we shall see how this plays out in the months ahead.
Slim
Good morning. It was a wet weekend and more rain is on the way. This has been a wet October here at Grand Rapids and just to the north of GR there have been reports of well over 8” of rain. 8.87” at Reemas, 8.55” at Mears, 8.52” at Shelby and 8.04” at Grant. At Grand Rapids the official amount so far is at 6.00” But just 2 years ago Grand Rapids had 9.69” of rain in October and that Halloween there was 0.4” of snow fall in the morning. That brings me to let everyone know that snow in October and November dose NOT mean we will get a lot of snow for the upcoming winter season (for the most part) as I stated in October 2017 GRR had 0.4” of snow in October but that November only had 0.2” of snow and while December did have 32.9” of snow it did melt between snow falls. January 2018 GR only had 12.6” there was more but still not a lot in February with 20.7” and only 4.9” in March.
The H/L at Grand Rapids yesterday was 55/39. While I got down to 34 at my house overnight with some frost the official low at GRR was just 38. For today the average H/L is 56/38. The record high is 74 in 1989 and the record low is 23 set in 1969. Last year the H/L was 48/36.
Slim
Currently 39* degrees out thee YARDofBRICKS NE of GR not sure how some thought October would be a dry month we are approaching 8 inches of rain now for the month probably the wetiss Fall I Can remember in a long time out at thee YARDofBRICKS and for the last time I ran the rider yesterday getting the yard cleaned up it’s a muddy sponge out there the rest of the leafs that fall will wait to the spring the battery is out of the rider the plastic is up on the windows the bag of salt is on the porch and the snow shovels have taking the place of the rakes reality post and reality folks Winter will be knocking on our door in just a few days … Probably the worst Halloween in years up coming for all the little tricky treaters followed by some pretty cold air moving in….MV Rocky Slim get ready Winter is coming early this year …Have a good Monday ..INDY.
Indy, This October will be a wet one for sure, but in 2017 Grand Rapids had 9.69″ of rain and there was 0.4″ of snow fall on Halloween morning (it melted before the little ones went out)
Slim
I remember 2017 because we had several roads damaged from flooding that year. This year has been wet but it’s been spread out so no flooding. How much rain did we have last year? That was a wet one to I believe.
5.69″
Slim