The End of Winter

Sunday marks the end of climatological winter. The official stats will be mentioned in this space next week, but preliminary numbers suggest we finished the winter nearly 2 degrees below normal. This was our third straight colder than average winter, albeit, not quite as cold as the past two.

There were two interesting temperature features to this cold season. First was the number of below zero days was well below the number of the past two winters, yet with a similar seasonal average temperature. Second, our warmest temperature these past three months was only 36 degrees which ranks as the 3rd coldest winter maximum since 1881 and the coldest since the 1970s.

But the winter of 2009-10 will likely be remembered most for the record breaking precipitation with 4.28 inches measured which is nearly one-half inch above the old record of 3.81 inches set back in the winter of 1896-1897.

Cold Snap for the Ages

It was during this week in 1936 that residents in North Dakota and northern Minnesota were thinking positive thoughts, literally. After nearly six weeks, the temperature finally climbed above zero for the first time. In Fargo Moorhead, the temperature never climbed beyond 0 degrees from January 15 through February 20, a total of 37 days. In some locations, including in Langdon, North Dakota, that stretch was even longer.

At no point since 1881 when records started has there been a streak of cold weather quite like it. During that stretch the coldest high temperature on record was observed at -29 degrees on January 22, 1936. Some of you may remember we came close to tying that mark when a high of -28 degrees was recorded on February 1, 1996 during a brutal, albeit much shorter cold snap. The second longest stretch of weather with a high at or below zero is 11 days, recorded in both 1996 and in 1899.

Snow Cover

The snow event in the southern United States during the second week of February, in combination with other snowfalls in Asia, increased the Northern Hemisphere’s snow cover to 52,166,840 square kilometers (around 20 million square miles).

That was the 2nd highest snow extent on record with only a week in February, 1978, having recorded more snow on the ground. Such records go back only 43 years so it is very likely there have been numerous other times with similar or more snow cover around the hemisphere, but within living memory for many of us, such a snow extent has been rarely observed. Additionally, the North American snow extent record was broken that same week and the day after snow fell in extreme northern Florida, nearly 70% of the lower 48 states reported snow on the ground.

Currently, that figure is near 60%, but a couple of systems to our south next week may increase the snow cover once again.  This winter continues our trend for an increase in snow cover over the Northern Hemisphere in the past two decades (contrary to popular myth).

 

 

 

Spring Forecast

updated as the CPC changed their forecasts this morning…

With most of meteorological winter behind us, thoughts now turn to what the upcoming spring months may bring for temperatures and precipitation to this area. All seasonal forecasting is difficult, but both autumn and spring bring the most difficulties because of the transitional nature of those seasons. Currently, the Climate Prediction Center is forecasting March, as well as the entire three month spring season of March through May with equal chances for above, below or average temperatures and precipitation in North Dakota and most of Minnesota.

Personally, I am leaning toward March into early April to be below average for temperatures as our widespread deep snow cover will likely inhibit our temperature potential until our snow pack disappears in about 6-8 weeks. Precipitation-wise, two storms made this winter exceptionally wet. My suspicion is this spring will be the same; one or two systems final storm track may be the difference between us being wet or dry.

Spring Forecast

Updated as the CPC changed their forecasts this morning…

With most of meteorological winter behind us, thoughts now turn to what the upcoming spring months may bring for temperatures and precipitation to this area. All seasonal forecasting is difficult, but both autumn and spring bring the most difficulties because of the transitional nature of those seasons. Currently, the Climate Prediction Center is forecasting March, as well as the entire three month spring season of March through May with equal chances for above, below or average temperatures and precipitation in North Dakota and most of Minnesota.

Personally, I am leaning toward March into early April to be below average for temperatures as our widespread deep snow cover will likely inhibit our temperature potential until our snow pack disappears in about 6-8 weeks. Precipitation-wise, two storms made this winter exceptionally wet. My suspicion is this spring will be the same; one or two systems final storm track may be the difference between us being wet or dry.

CoCoRaHS

CoCoRaHS is a unique, non-profit, community-based network of volunteers of all ages and backgrounds working together to measure and map precipitation throughout the United States.  Their homepage is http://www.cocorahs.org

I was asked to help make a background and training video for the organization.  You can view this video here:


http://www.youtube.com/watch?v=HKlpFuaLw0I



We could use many more volunteers, plus, it can be a lot of fun to help collect and monitor the weather.  The rain gauges they use for this effort are manufactured in Fergus Falls, MN!  So you can help a local business at the same time.

 

 

A Sign of Spring

Although temperatures have remained below freezing the past several days, you may have noticed some melting on the roads during the afternoons. We are nearly two months past winter solstice and the Sun has once again reached a sufficient angle to warm the roads, roofs and buildings to above freezing each afternoon no matter what the actually temperature is. This will help to slowly improve the icy road conditions, especially on secondary roads and city streets over the next couple of weeks.

But this melting also brings some problems. With road temperatures quickly dropping to below freezing as the sunsets, the water on the roads quickly turns to ice which rapidly changes the travel conditions each evening. Also, this frost freeze cycle each day will help create potholes as the melting water seeps into cracks in the roads, expanding on freeze up each night, which slowly breaks apart the roads. Our slow transition to spring is finally beginning.

24 hours of Negative

February 9 marked the average last date that Fargo Moorhead records a high temperature below zero. So far this season we have recorded six such days with the last occurrence being on January 8. If by chance we do not observe another day with temperatures remaining below zero for a high, it would be the earliest such last occurrence since the winter of 2001-2002 when we managed to go through the entire winter without a maximum temperature below zero.

Last year we recorded 14 days with a high temperature below zero, including one of the latest on record when we had a high of -1 degree on March 11, 2009. The record for the latest below zero high was set on March 24, 1974.

So although the odds favor us not observing a negative high temperature until next winter, if we do, it will likely come after a fresh snowfall and a day with a light wind.

Freaky Weather?

In the past week, Washington, D.C., Baltimore and Philadelphia all broke their seasonal snow records. Then a separate system brought snow even farther south from north Texas to South Carolina. Light Snow accumulations were witnessed as far south as extreme northern Florida. Dallas-Fort Worth officially recorded 12.5 inches of snow last Thursday. That broke the record for their highest daily snowfall.

It also, to this point of the winter, makes it the 2nd snowiest winter on record in the Dallas area. I have heard numerous pundits give all sorts of explanations from El Nino, Global Warming to Global Cooling as reasons for the snowy winter in the United States. Although the explanation of El Nino does have some merit, sometimes we have to remember that weather is just weather.

There are many atmospheric events that only occur every 30 to 50 years; this does not make them freaky, just rare.

Cold, yet Warm

Record snow, record cold, sea ports closed because of ice forming where it has not been observed in decades, yes, this winter has been a cold one throughout much of the Northern Hemisphere, or has it? The United States, especially the lower 48 states, much of western Europe and China, three of the major populations centers have indeed experienced a relatively hard winter to this point.

But on a whole, the Northern Hemisphere is actually experiencing a warmer than average winter and the entire planet experienced the warmest January since 1978. Global circulation patterns associated with El Nino and oscillations in the arctic have kept the high and low latitudes with above average temperatures in recent weeks, yet the mid-latitudes have been exceptionally cold and snowy.

This is one of many reasons why trying to equate global or even regional weather into a single figure misrepresents the true nature of how the weather works and impacts the planet.