Halfway through April and it is looking like another colder than average month. December, January, February, and March have all been significantly colder than average. April will likely make five months in a row. Last October and November were also colder than average but only by an insignificant fraction of a degree. September was warmer than average but the summer months last year were only slightly warmer than average. Average is only the average of the past. There is no rule that weather has to conform to averages either by remaining near average or by swinging equally one way and then the other. In this sense, our weather is non-linear, which means it does not converge to an average over time. We present weather averages only as a way to roughly compare. For most weather records, what we call, “average” is only the average of the past three full decades. So what constitutes average weather actually changes over time as our climate goes through changes. Meteorologist John Wheeler
Two scholars at the University of Chicago’s Oriental Institute have translated an ancient Egyptian inscription on a six-foot stone block which seems to be a 3.500 year old weather report. The writing on the block refers to rain, darkness and “the sky being in storm without cessation, louder than the cries of the masses.” This is now believed to be the oldest weather report ever found. It is possible that this terrible weather may be a result of the Minoan eruption of Thela in the Mediterranean Sea, on the island now known as Santorini. The Thela eruption is thought to be one of the strongest and most devastating volcanic eruptions of the past several thousand years. Climate scientists have found evidence of sudden and severe climate change throughout the Northern Hemisphere, including tree ring data in Greenland, bristlecone pines in California, and reports of crop failures in China. Such massive volcanic eruptions can change climate by ejecting huge amounts of sulphur dioxide into the upper atmosphere where it blocks sunlight for years. Meteorologist John Wheeler
Saturday, March 29, 2014
A storm system in California Wednesday produced a number of mostly small and relatively weak tornadoes. Social media resonated with non-meteorologists making claims about weird and changing weather. However, California has a history of tornadoes. Though not as common as in the Great Plains, California gets tornadoes almost every year. They usually happen in winter and spring when powerful low-pressure systems move in from the Pacific Ocean with strong rotation. California tornadoes tend to be weaker than in the Great Plains because California weather rarely sets up with contrasting temperature and humidity conditions like what we often get in the Plains around frontal systems. The states with the fewest tornadoes per square mile are Alaska and Hawaii. John Wheeler
Fargo Moorhead averages 48 days with a temperature dropping below zero during our cold season. Of those 48 days, on average, December records 12 of them. Including this mornings expected below zero reading, the temperature has already dropped below zero on 16 days this month. If current projections are correct, this December could end up with 20 or more negative temperature days.
Fargo Moorhead has recorded 20 or more days with a temperature dipping below zero degrees only five times in the month of December in the past 30 years. Those years were 1983, 1985, 1989, 2000 and 2008. This month already ranks as having the second most below zero reading this century (since 2001) and may join that 20 club before the month is done.
What this means of course is, if you have been thinking this month has seemed a bit cold, even by our standards, these statistics prove you are correct.
The average high today is 31 degrees. The average high will stay below freezing until March 8 when that average will finally be back to 32 degrees. During the three principle months of winter, December through February, Fargo Moorhead averages 18 days with a high temperature above freezing.
n four out of the last five winters, we have recorded a below average number of melting days. The one exception was during the winter of 2011-2012 when on 47 of the 91 days that winter the high temperature was above freezing. That is the most of any winter on record. Of note, the other four of the past five winters in total had only recorded 47 days above freezing, an example of how unique the winter of 2011-2012 was for warmth.
The record lowest number of winter days above freezing is two such days that occurred during the brutal winter of 1978-1979.
Last week on Halloween, 42 tornadoes were reported across the country. Most of those were confirmed with storm survives over the following days. That was the most tornadoes reported on October 31 since at least 1950. That was also the highest daily tornado count in the United States since early July.
Yet, even with a high number of tornadoes recorded last week, the 2013 season overall has been one of the quietest since good severe weather records started in 1950. Not only has the tornado season been quiet, but so has the Atlantic hurricane season. Through October the Accumulated Cyclone Energy (ACE) index was the 4th lowest since 1950 for the Atlantic basin.
Plus, it will probably be another year without a major hurricane strike on the lower 48 states, continuing the longest such streak since at least the Civil War.
October seems to be one of those months that no one really expects it to snow, yet, when no snow is actually measured, many seem to get surprised by that as well. One reason perhaps is that October snow has been fairly common in recent years. Fargo Moorhead averages just 0.7 inches in October. yet five out of the past seven years have recorded more than one inch of snow.
Historically, measurable snow has occurred in 45% of all Octobers since snow records have been kept, making these recent snowy Octobers seem more typical then it has been historically. Most years any snow this time of year is in smaller quantities as it only takes 3.8 inches to make it into the top 10 snowiest Octobers on record. Last year we came close to that finishing as the 11th snowiest when 3.6 inches were measured.
This year we tied with numerous years as the 60th snowiest October on record with just a trace being reported.
The average temperature through the first 10 months of 2013 is running about 1 degree below average. Seven of the ten months this year recorded temperatures reasonably close to the average with most of them finishing just slightly above normal. September was the only month so far this year that finished well above average. The temperature last month was 5.3 degrees above normal.
But the reason this year as a whole is running below average is because of the extremely cold March and April this region recorded. April 2013 was the coldest April on record for the state of North Dakota and ranked as the 3rd coldest in Minnesota. April finished more than 10 degrees below average in Fargo Moorhead after the month of March had also finished more than 10 degrees below normal.
Therefore, 2013 will probably finish as colder than average overall principally because of those two very cold spring months.
Six months ago today was also a Friday and many of us were waking up to snow on the ground. In Fargo, 1.4 inches had fallen the previous day and although most of it had melted before sunset, there was still a touch of white covering the ground. But in northwestern Minnesota, 3 to 6 inches of snow had fallen with the ground still very white on that chilly Friday morning.
Although most of the reports from that October 4 snow event stayed under 6 inches, there was a small area around Badger, Minnesota that recorded between 10 and 15 inches of snow. That of course is a significant snow storm for any time of the year, but especially in early October. The wet sloppy snow fell on trees full of leaves snapping branches and causing power outages that lasted for a few days in some locations. Here we are six months later with snow still on the ground and the potential for more.
Perhaps it was not the worst cold season on record, but you are not mistaken if you think it has been a very long winter.
The strong wind that accompanied the arctic cold front that moved through the area on Saturday, not only brought cold and blowing snow, but also a layer of snirt. For those of you unfamiliar with the term, snirt is a mixture of dirt and snow.
The lack of snow cover in the area has left many of the fields partially exposed. That allowed the strong wind on Saturday to pick up some dirt that mixed in with the blowing snow. Although not all areas have a noticeable brown hue to the snow, but the areas that do, it is most noticeable on the tops of the drifts. The past two decades have recorded so many snowy winters that snirt is a word that has not been used much, but historically dirty snow was much more common.
The famed “Super Bowl Blizzard” of 1975 that crippled much of Minnesota did not drop much snow locally, but the wind was so fierce that houses were covered in so much snirt that in North Dakota it was referenced as the “Black Blizzard”.