Gut Feelings Worth Little/Nothing

 

Since this warm spell began, many people have asked me about “gut feelings” (theirs or mine), as to how much winter weather remains. The premise being that a number of people “have a feeling” we have seen the last of snow and cold.  A good weather forecaster does not use “gut feelings” to make a forecast because such a premonition would be baseless.  Colder weather and even snowstorms could happen with a change in the Jet Stream.  The physics models we use to make our seven-day-forecasts actually run out to more than two weeks.  It’s just that they are terrible at such a range.  Other forecasting tools, such as circulation anomalies, are sending mixed signals as they often do in spring.  So this meteorologist is comfortable saying any spring/summer forecast is as good as anyone’s gut feeling, which is essentially worthless. So enjoy the mild weekend weather.  It might last but it might not.   Meteorologist John Wheeler

 

Drought Talk Premature

Any discussion of drought in our region is March is probably premature.  It has been dry all around eastern North Dakota and northwestern Minnesota since the middle of fall but all our water needs are being met at the moment.  This all changes if the dry weather lingers past planting season.  After planting, crops will need rainfall to germinate. But a timely rain or two will get regional growers through.  By summer, the effects a continued lack of rain will depend on the temperatures.  If it is hot, evaporation rates will be greater and crops will need more rain.  If it is cool, crops can get by with less.  Reservoirs upstream are relatively full so unless the drought is severe, rivers should not drop to low.  But again, a combination of severe drought and high temperatures could cause municipal and other water shortages.  Of course, none of this has happened, yet.  Thus, any discussion of drought in March is probably premature.     Meteorologist John Wheeler

March Blizzards

 

It is a myth that there are always huge blizzards in March.  In the distant past as well as in recent years, March and April pass without any blizzards at all.  Of course, it is also true that some of our most severe blizzards in history have happened in March.  Across North Dakota, the benchmark for blizzards may well be the monster blizzard of March 3-6, 1966, when one to three feet of snow with winds 50 to 100 mph built drifts 30 feet high.  But March is not the only month with a tendency to produce memorable winter storms.  All of the cold months from October through April have produced at least a few severe blizzards.  Interestingly, the big ones are most common in three of the months; November, January, and March.  November and March provide the greatest proximity of warm and cold as the seasons change.  January is the king month for hybrid Alberta Clipper storms connecting with super strong Arctic high pressure systems.   John Wheeler

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Average is Average

 

Average March snowfall is 9.1 inches.  Average April snowfall is 3.0 inches. This does not mean we are for sure in for a foot of snow before spring.  Nor does this mean we should expect around a foot of snow unless something goes wrong with the weather.  What is average implies nothing about what is supposed to happen.  Average is derived by taking an average.  Almost all of the time, weather is above or below average and the average is just the middle of all the samples.  We usually use the average of the three most recent complete decades to calculate the average.  At present, we are using 1981-2010 to compute our averages.  Each new decade the averages change.  This is so what we refer to as average keeps up with the gradual changes in our climate without overreacting to sudden swings in year-to-year weather.  We might get very little snow during March and April.  Or the storm track could change and we might get a lot.  That’s weather.  That’s all.    John Wheeler

 

If You Want a Big Spring Blizzard…

 

In order for us to get socked by a blizzard this spring, the pattern will need to change.  At present, the Polar Jet Stream is too weak and to far north to be a threat.  The far more active Subtropical Jet Stream could shift northward and bring snow, but a real blizzard would not be likely from such a set up.  The few near-blizzards we have had this winter have been brief rounds of blowing snow in the open areas of the Red River Valley.  And with limited snow cover and very little falling snow, conditions have been marginal at best as blizzards go.  Serious Great Plains blizzards are born along a fast and active Polar Jet Stream.  Some ripple in the wind field out over the Pacific Ocean grows into a full-fledged kink in the Jet Stream.  As it crosses the Rocky Mountains, the differences within the system widen and the low pressure deepens.  As the system closes into a circle throughout the lower and middle atmosphere, fierce winds and heavy snows develop and woe is he who gets in the way.   Meteorologist John Wheeler

 

Here Comes the False Spring

The limited snow cover this winter is a big reason for the warm up coming the next few days.  The milder weather is primarily a result of upper level winds and not the lack of snow, but it is the lack of snow which will likely cause several of the next few days to be anywhere from five to fifteen degrees warmer than they would have been had there still been significant snow on the ground.  Although the sun’s rays feel warm on our faces, sunlight does not heat the air very much at all.  The sun is mainly able to warm the atmosphere indirectly, by heating the ground with radiation (They’re not called sun rays for nothing.), which then heats the air through convection.  When the ground is white with snow, most solar radiation is reflected, so the air remains much colder.  The melting of the snow may give us an early spring, but it may well be a false one.  Weather history suggests a return to a snow-covered landscape is likely before spring comes to stay.     Meteorologist John Wheeler

Winter: It’s a Gas

One added benefit of warmer weather in March is better gas mileage in our cars.  Cold weather causes a significant drop in fuel efficiency, especially in very cold winter climates like ours.  There are several reasons for this.  Colder motor oil and other fluids cause greater friction in the engine.  Cold weather causes tire pressure to drop, increasing friction.  Winter grades of gasoline have a little less energy than summer grades.  Outside the vehicle, the denser cold air adds additional drag force.  Finally, slick roads cause the wheels to slip and that is wasted energy.  All of these things add up to a ten to thirty per cent reduction in fuel economy during winter.   Meteorologist John Wheeler

February Review

February has been the wintriest of the winter months this year.  The average temperature for the month was about seven degrees which is about six degrees below the long term average for February.  The coldest temperature was nineteen below on February 19th and again on the 22nd.  There were just two days thawing temperatures during the month.  It was 34 on the 6th and 36 on the 7th.   For comparison, the average January temperature of 16.0 is 6.7 degrees above average.  The average December temperature was 21.1 degrees is 7.0 degrees above average.  Snow amounted to 8.1 inches, which is near the average for the month, making February by far the snowiest month of the winter so far.  Total winter snowfall in Fargo Moorhead is still just 15.6 inches.    Meteorologist John Wheeler

 

Boston Snow Scale

It still is amazing to think of just how much snow fell on the greater Boston area from late January through today.  Almost eight feet of snow (94 inches) has fallen on downtown Boston since January 24.  But we often refer casually to all that snow “in the East” without really thinking about how large the affected area is.  Not to take anything away from what Bostonians have endured, but we need to realize that not the entire Northeastern U.S. is buried in snow.  All of New England together (71,992 square miles) would almost fit into North Dakota (70,762 square miles).  Massachusetts would fit into the Red River Valley.  And it is primarily eastern Massachusetts, eastern Connecticut, northern Rhode Island, southern Vermont, southern New Hampshire, and much of Maine that is unusually snowy.  This is an area about the same as the WDAY-TV viewing area, which was similarly buried in snow the winter of 1996-97.  Meteorologist John Wheeler

Sign of Spring

Although the weather is still cold, on almost any sunny day there is meltwater visible on streets, sidewalks, and parking lots.  The days are getting longer but, more to the point, the sun is getting higher in the sky.  The more direct sunlight is able to pass through the atmosphere and heat the ground.  Bright, white snow reflects a lot of the sunlight, but darker surfaces like roads and roofs absorb some of the rays and warm up.  Even on a cold late-winter day, with temperatures barely above zero, there will be melting. Look closely and you will see steam rising off some of these dark surfaces, too.  Steam forms in the cooler air over a pan of boiling water and this is a similar process.  Runners and walkers will notice that streets and sidewalks are not so icy this time of year during the daytime, although the occasional splat of slush can be a cold slap on a bitter day