Windy Again

There have been several inquiries into the WDAY Weather Center office lately about how unusually windy the spring has been.  April is, on average, the windiest month of the year, with an historical average wind speed of 13.9 mph for the month.  This number may seem low, but consider that April nights are not usually very windy so a lot of that average wind speed comes from very windy afternoons when the sun is shining down on bare, black soil creating turbulence.  Well, the average wind speed so far this month has been about 13.9 mph; exactly the average.  However, over the previous five years, the average April wind speed in Fargo Moorhead is 12.0 mph; considerably below average.  So it turns out that this spring is closer to the long term average for wind.  But a run of calmer Aprils has skewed our memories.

Meteorologist John Wheeler

The Drought of 2015?

One can only say our region is “one good rain away from being just fine” so many times before it starts to sound ridiculous.  The region is dry and has been dry since the start of last fall.  The drought has received very little attention because the only ill-effect so far has been a few windy days with a few wild fires, which happens lots of times in spring.  But May and June will bring consistently much warmer temperatures and higher evaporation rates so that, without good rain, things will start to get very dry.  It will begin in the fields where crops will begin to wither.  It will eventually show up in towns and cities with lawn watering restrictions.  Years of wet weather have built up a supply of water in upstream reservoirs so there is no concern about extreme restrictions for a while.  We will not run out of water this summer, but we may face significant impacts if it does not start raining.

Meteorologist John Wheeler

 

Will the Dry Trend Last?

 

Sunday, April 26, 2015

Both of the past two winters, there has been a sharp divide between a cold and snowy eastern U.S. and a warm and dry western U.S. Caught in the middle, our region was cold and dry in 2013-14 and mild and dry this past winter.  The dryness is related to the northwest to southeast position of the Polar Jet Stream, coming over the top of the western high pressure ridge responsible for the western warmth and diving south around the stalled out eastern low pressure area.  This setup creates storm systems without a good moisture supply. Research points to a large, horseshoe-shaped region of anomalously warm water over the eastern Pacific Ocean with the head against North America, one arm along the Alaskan coast and the other arm pointing southwest from California. This explains the intensity of the California drought and suggests our Northern Plains weather could continue to be drier than average for a while longer.       Meteorologist John Wheeler

Average Frost is a Toughie

 

The date of the last freezing temperature in spring is one of the most volatile statistics in the record book.  Historically, the final “frost” has been as early as April 17 in 2007 and as late as June 20 in 1969.  For the first ten years of record, 1881-90, the average last frost date was May 21.  Over the last ten years, the average last frost date has been May 6.  The difference in the averages amounts to 15 days.  However, the final frost dates in the 1880s varied from May 3 to June 8.  Over the past ten years, the final frost has varied from April 17 to May 27.  This highlights the fact that even though the last frost is happening earlier on average, it is not necessarily happening earlier in any particular year. Even with the trend of earlier final frosts, a very late June frost remains a possibility in any given year.   Meteorologist John Wheeler

 

Late Spring Snowfalls

The flurry of snow showers earlier in the week brought many questions about the rarity of late April snowfalls.  Flurries, such as the mostly trace amounts we saw Monday and Tuesday, are quite common. But measurable snow at the tail end of April and even into May does happen from time to time.  A quick scan over the past few years reveal several measurable snowfalls in Fargo Moorhead this late. April 24, 2013; May 1, 2011; April 26, 2008; and May 1, 2005.  All of these were light accumulations of an inch or two or even less than an inch.  As frequently as these late spring snows happen, they always seem to come as a surprise to many of us.  This May be due to the fact that spring snows usually melt too quickly to form much of an impression.    Meteorologist John Wheeler

 

Is This a Drought?

Drought is not a disease of the weather.  It is not contagious.  Drought is just a lack of precipitation.  Causes of drought are complex.  There is nothing in our atmosphere; no known circulation or recognized anomaly; which is certain to cause a drought.  Also, it is impossible to know when a drought has begun.  We cannot know if a short-term dry spell will become a full drought until it has been dry a long time. So is our area in a drought?  Yes it is, because outcomes are beginning to appear.  Prairie fires this spring are much worse than usual.  As soon as growers in the region start to plant, there will be a problem because there is not enough moisture in the top soil to sustain the crops for long.  All of this could change with one or two good rains.  But until that happens, our region is undoubtedly in the beginning stages of a drought.  Meteorologist John Wheeler

Just 16 Inches

 

It has been more than a month (March 6) since snow was on the ground for more than a few hours. And while a late season snow is still a possibility, it looks less likely every day.  Total snowfall for this winter for Fargo Moorhead stands at 16.0 inches, the least since 13.1 inches fell in the winter of 1980-81, and the eighth least snowy going back to 1885.  The heaviest snowfall of the season was 3.5 inches on February 10.  The deepest average snow depth was 5 inches from February 15-18. As there is historical precedent for a winter with so little snow, it would be wrong to call this a freak winter or an abnormality.  For cross-country skiers, snowmobilers, and business owners who depend on snow all there is to say is, “Better luck next time.”    Meteorologist John Wheeler

Will Dry Get Drier?

 

It has been dry.  There was very little winter snow and, so far, only a few light showers this spring.  Any windy day causes blowing dust in the fields.  Each warm day causes more and more evaporation which leaves the ground drier and drier.  Many farmers in the area are concerned that the lack of rain will soon impact the growing season.  And while all of these concerns are real, it is important to realize that our region is one good storm away from being quite wet.  One two-inch rain is all it would take to saturate the soil and start greening the grass.  Even a one-inch rain would be more than helpful.  At present, there is no sign of that first good rain of summer.  The pattern will likely keep most of the good rains away from our region for a while.  And if the sky remains dry, the ground will only get drier.    Meteorologist John Wheeler

Dressing For Easter

Easter is, of course, a Christian holiday celebrating the resurrection of Jesus.  It is also a celebration of spring celebrating the rebirth in nature.  The symbolism of the rabbit distributing eggs makes this obvious.  Standard dress for Easter Sunday includes such spring-appropriate clothing as a pretty spring dress and bonnet or a new suit.  These outfits may or may not be comfortable, depending on the weather. And while Easter does occur in spring, the actual date varies.   In the year 325, at the Council of Nicaea, it was established that Easter would be held on the first Sunday after the first full moon occurring on or after the vernal equinox.  This means Easter in any year can fall between March 22 and April 25.  High temperatures in Fargo Moorhead during this period have ranged from one below zero (March 24, 1974) to 100 degrees (April 21, 1980).  It is difficult to dress for such a range.      Meteorologist John Wheeler

Are You Tornado Prone?

After last week’s first tornado outbreak of the season produced yet another tornado in the city of Moore, Oklahoma, there has been much speculation as to why Moore seems to have become be a tornado target in recent years.  Some have speculated it could be a subtle feature of geography; a combination of the slope of the land and proximity to urban areas causing natural enhancements to thunderstorm inflow.  However, actual results seem to defy such explanations.  Tornadoes are so isolated and uncommon in any one place that it is very hard to find empirical evidence for such conclusions.  Likely as not, when a particular location seems to be tornado prone, it is just random luck.  The forces within a supercell thunderstorm are strong enough to dwarf any local geographical effects.   Meteorologist John Wheeler