Continental vs Maritime

The temperature this month in Fargo Moorhead has ranged from eleven below zero to 75 degrees for a range of 86 degrees in a month.  It’s hard to dress for that.  Fargo Moorhead is a perfect example of a continental climate in which the temperature can vary as air is blown around the region by various random weather patterns.  The greatest one-day range was 44 degrees on March 14 when it was 24 in the morning and 68 in the afternoon.  In contrast to this, the temperature this month in Key West, Florida, has ranged from 69 degrees to 84 degrees for a range of 15 degrees.  The greatest one-day range was 13 degrees from a low of 69 to a high of 82.  Key West weather is maritime.  The temperature of the surrounding ocean dominates the weather, keeping daily as well as day-to-day changes minimal.  Meteorologist John Wheeler

Drought and Heat

The official thermometer for downtown Los Angeles has already recorded four days in the 90s this month.  This is a record for so early in the season.  As California starts its fourth summer of drought conditions, the expectation is there will be a lot of hot days which, in Los Angeles, will mean many summer days in the 100s.  There is a very close relationship between drought and record heat.  Here in Fargo Moorhead, 29 of the 92 summer daily record highs (June 1 through August 31) were set in the 1930s which is by far the driest decade on record here. The connection is simple.  When the soil is dry, it is heated up more efficiently by sunlight, which makes the air hotter.  Summer droughts create dry soil and usually have lots of sunny days. Since 1993, the Red River Valley has been quite rainier than the long-term average, and so summer record highs have been rare in recent years.   Meteorologist John Wheeler

Late Season Snow Likely

After an early spring, threats of snow have rematerialized in our forecasts on a routine basis.  Late-season snows are typical enough that even April carries a monthly snowfall average of three inches.  Last year, Fargo Moorhead got a 2.3 inch snow on March 31 and a 1.5 inch snowfall on April 16.  Two years ago, we got buried by 9.1 inches on April 15-16 followed by another 3.2 inches on April 17-18.  Late season snows usually melt quickly but often provide more shock value than the snowstorms that happen in the middle of winter.  My own interest in meteorology as a lifetime profession was probably triggered by a now famous spring snowstorm that covered southern Wisconsin (and me) in 12-18 inches of snow April 7-8 or 1973.  My family had just moved to the Midwest from Alabama the previous summer and that April snowstorm was my first blizzard.     Meteorologist John Wheeler

Going to Extremes

March 23 is an interesting day in the Fargo Moorhead weather record book.  With records dating to 1881, there are two versions of this particular date which stand out.  In 1910, it was 80 degrees.  This remains the only 80 degree day in March in the history of Fargo Moorhead.  The spring of 1910 was extraordinarily warm and dry and with the drought lasting well into summer, it was a year of many crop failures.  From the opposite end of things, March 23 of 1974 remains the latest day in the year on record with a subzero high temperature.  That was one of those years in which spring seemed to never show. And following a week of cold days and a fresh two inch snowfall on March 22, the 23rd delivered a low of eleven below zero and a high of one below. These are two extreme illustrations of how variable the weather can be in March.   Meteorologist John Wheeler

First Day of Nothing

Friday, March 20, is the Vernal Equinox.  Many people call this the first day of spring without thinking much about it.  Can spring start at the same moment everywhere on Earth?  Think about the equatorial regions.  At the equator, March and September are when the sun is directly overhead at noon.  It is hot all year at the equator.  But it is often hottest in March and September.  The weather is also rainiest and most humid along the equator around the time of the equinoxes because the direct sunlight causes peaks in evaporation rates to go along with the peaks in temperature.  Around the time of the Solstices in winter and summer, the middle of the world has its two slightly less hot seasons.  So there are relationships between the equinoxes and weather, but they are general and varied around the world.  The Vernal Equinox is really an astronomical moment with no immediate impacts on the weather anywhere.  This makes the “first day of spring” a fairly useless concept.    Meteorologist John Wheeler

Tornado Absence

 

March is typically one of the peak months for tornadoes in the United States.  Though rare so early in our region, it is common for there to be big outbreaks in March across the Southern Plains or the Southeast.  This year, for just the second time since 1950, there were no tornadoes reported across the country from March 1-15.  The other year was 1969. The cause for this year’s absence of twisters is, of course, the jet stream pattern, which has kept the Great Plains extremely dry this month so far.  And although the Southeast has been rainy, the rains have been general soakers.  The pattern just has not favored the development of tornado-producing supercell thunderstorms.  This should not be taken as a sign that our warm season will be free of tornadoes.  Meteorologist John Wheeler

Aurorae Come and Go

Northern lights, also called Aurora Borealis, were seen over much of our region by a great many people Monday and Tuesday nights.  Northern lights are caused by high energy particles emitted from the sun.  When these supercharged particles reach Earth, they react with gasses in the upper atmosphere, releasing photons in the process.  The photons glow varying colors based on the gas.  Oxygen glows green.  Nitrogen glows red. Earth’s magnetic field concentrates the particles, and the aurorae, near the magnetic poles, which is why we see them more frequently in the north-northeastern sky.  Aurorae are more frequent and often more brilliant during times of heightened solar storminess.  The frequency of solar storms is related to the eleven year solar cycle but these are not identical.  In fact, they vary greatly.  During the 1990s and 2000s, northern lights at our latitude have been seen less frequently than they were back in the 1980s.  The present cycle has been more active.   Meteorologist ohn Wheeler

 

Too Wet or Too Dry

As the winter snow melts from the fields around the Red River Valley region, there are just two possibilities for soil conditions.  It can be too wet or it can be too dry.  The concept of “just about right” almost never works in the early spring.  If winter snow was substantial, or even average, the frost in the ground makes it hard for moisture to be absorbed.  So the soil tends to remain soggy and any rain tends to just sit there and make mud.  Spring field work has to wait for drier days.  If the winter snow cover was light, then the strong sunlight beaming down this time of year tends to evaporate what little moisture is in the topsoil and it gets dusty in a hurry.  This can be frustrating for the farmer who is either waiting for fields to be dry enough for work or else is planting seeds knowing they will require rain for germination.     Meteorologist John Wheeler

Drought Brings Good With Bad

Since 1993, the weather pattern over the Red River Valley region has been wet.  Dry periods within this time frame have been few and generally brief. Average annual rainfall increased 15-20 per cent starting in 1993.  The weather has been wetter and for a longer period than the dust bowl years were dry.  Eventually this pattern will end but it is not possible to know in advance if the change will take place in another hundred years or if is starting right now.  Weather is difficult that way.  Although drought is hard on our overall economy and water shortages can make life more difficult, drought is a naturally occurring part of nature.  It has a way of rebooting wetlands, leaving them healthier and more productive.  A drought would lower the almost annual flood threat by lowering reservoir levels.  And a drought would lower Devils Lake.   Meteorologist John Wheeler

Prairie Fires

 

Each of the last two spring seasons has been cold, wet, and late.  This one has come in early and dry. This could mean a lot more grass fires this spring.  Pre-historically and historically, prairie fires were common across our region in spring.  As the snow melted each spring, hundreds of square miles of dead grass lay on the ground just waiting to burn on a hot, dry, windy day. All it needed was a bolt of lightning from a light thundershower.  As our terrain has given way to agriculture, grass fires have been reduced to ditches and the few remaining stretches of prairie.  Still, an out-of-control fire is extremely dangerous. It is possible even today for fires to grow large enough to put farmsteads and even whole towns at risk.  And today’s fires are more easily started by careless smokers, trains, or accidental controlled burnings growing out of control.   Meteorologist John Wheeler