September Snow

In a recent blog I mentioned how some parts of
northwestern Minnesota
had already seen a bit of snow a couple of weeks ago.  The question was then raised to me, how often
has it snowed in Fargo/Moorhead during the month of September? 

Locally, we have seen just four measurable
snow events since our records began in 1881. 
The biggest snow event was on September 25, 1912 when two inches of snow
was measured.  The earliest reported
snow, which amounted to just some flurries in the air, was back on September
15, 1956.  The last time snow was
reported during September in Fargo/Moorhead was back on September 21,
1995. 

So although we did not see snow
this year and it has been over a decade since the last reported September snowflakes,
it will certainly happen again.

Autumnal Equinox

Today marks the Autumnal Equinox.  The equinox part
stands for equal, as in equal days and nights for all locations around the
planet. 

But there is a problem, if you look at the sunrise and sunset times for today in Fargo/Moorhead and other
locations, you will notice that instead of 12 hours of sunlight today, we have 12 hours and approximately 10
minutes.  Where does this extra ten minutes come from?  It deals with how
sunrises and sunsets are measured.  Today marks the day when the
middle of the sun is directly over
the equator, but we do not measure sunrises and sunsets this way. 

Instead, we measure not when the
middle of the sun is on the horizon,
but when the edge of the disc first comes up or falls below the horizon.  So
this difference in timing equals about 5 minutes both in the morning and
evening.  So in other words, we’ll see our true equinox in two
days.

Early Snow

Before our current warm up began last Saturday, some areas
around Lake of the Woods saw snow for the first
time this season on the morning of September 14th.  Sleet, mixed with wet snow, was reported by
many individuals. 

You may ask, how
unusual is to see snow this early in the season?  A similar event occurred on September 12,
1923, but of a more widespread nature when much of northeastern North Dakota and especially northwestern Minnesota saw widespread
light snow and flurries.  So although not
unheard of, it certainly, even by northern Minnesota standards, was a very early taste
of winter. 

If you are curious, one of
the earliest significant snowfalls recorded was a band of 3 to 6 inches that
fell across portions of northern North Dakota
and Minnesota
on September 24-25 in 1912.

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Siberian Snow and the Red River Valley

With this September seeing many cold days and
with frost already seen in many backyards, you may be wondering what the
upcoming winter season will bring. 

Of
course nobody knows for sure, but one of the many things long-range forecasters
will be keeping an eye on will be the snow cover that develops in Siberia this October. 
Heavy October snows in Siberia have some skill in predicting winter
temperatures in the northern part of the United States.  An early and extensive snow cover in Siberia unusually leads to more frequent and severe
arctic outbreaks for our area. 

These
types of weather connections, like ocean temperatures (El Nino or La Nina), are
far from perfect predictors, but it will be something that will be carefully
watched in the upcoming weeks

Ice Records

You may have read that the Arctic sea ice this
summer reached the LOWEST level ever measured, covering an area of about 3
million square kilometers. This estimate from satellite data is about 20
percent less than the previous lowest value recorded in the relatively short
period that such data has been collected (since 1979).

What you probably have not read is that the Antarctic
sea ice (Southern Hemisphere) has also set a record this year, but for the HIGHEST
amount of sea ice cover ever recorded, around 16 million square kilometers. Both
records are relatively meaningless as records are so short and climatic shifts
usually occur over far greater periods than just 20 or 30 years.

As a side
note, this winter has been an especially harsh one in the Southern Hemisphere
with snow and cold records set in Australia,
South America and in Africa.

Summer of 2007

The first two months of summer, June and July, finished with
above average temperatures, but August finished slightly below average, 1.8
degrees to be exact.  August finished very
close to average rainfall with 2.39” measured at the airport which is only 0.13”
below the long term average. 

After a wet
start, the summer did finish near average for rain with only about a one-half
inch surplus, but the airport is still well above average (about four inches)
for the year because of the very wet April and May this area experienced. So if
you take the two above average months with the one below average month, the
summer as a whole finished just slightly above average temperature-wise and
nearly average as mentioned for rain. 

This past summer once again proves that an average summer overall, does
not necessarily bring many average days to this area.  So if autumn finishes near average, it will
likely come with many extremes just like our summer.