So far this June we have recorded a high temperature below 60 degrees four times (all in a row). The last June to record this many days with highs in the 50s was back in 1915 when five such days were observed. Only the years 1915 and 1897 (also a year with 5 such days) have recorded more highs below 60 degrees than we have experienced this month. Historically, Fargo Moorhead averages one day in June with a high in the 50s or lower with 114 such occurrences before this year. The last time we had more than one day in June with a high below 60 degrees was back in 1998. That year we ended up with three such days, including a high of just 51 degrees on June 2.
The summer of 1998 turned out to be a mild one being the 32nd warmest on record, so this year’s cool start of summer does not necessarily mean the entire summer will be cooler than average. Although, it should be noted the year 1915, the last similar June to start similar to this one, did end up finishing as the coldest summer on record.
Upon further research I discovered that since 1881 we have never had four straight below 60 degree highs in June before this year, so even by our cool standards this has been a remarkable stretch of cool weather for June.
The one to three inches of snow that fell around Dickinson this past Saturday, June 6, was the first measurable June snow in that area since 1951. According to the National Weather Service in Bismarck, this was the latest snowfall on record for the city. Accumulating snow was widespread in southwestern North Dakota with snow covering grassy areas to within thirty miles of Bismarck. The last measurable snow in that area was on June 1, 1951 when four to five inches of snow fell in both Dickinson and Bowman.
Before 1951 the only reference to measurable snow around Dickinson I could find in June was back in1898. Accumulating snow was also reported in parts of Montana all the way up to Calgary, Alberta over the weekend. The same disturbance brought snow late last week to the mountains of California.
Snowfall in North Dakota or Minnesota in June is certainly uncommon, especially the measurable events like the one that occurred this past weekend.
Pictures courtesy of the Samuel Family in Wahpeton who have relatives in Dickinson.
The latest global temperature anomolies for the month of May have been posted from UAH set. May finished 0.04 degrees C above average (1979 through 1998 temps). See plot below for the past 30 years of data.
A bit technical for some at times, but below are two links that will give an excellent summary of the weather conditions that may have brought down Flight 447 over the Atlantic Ocean
The tragedy of the Air France Airbus crash in or near the Intertropical Convergence Zone (ITCZ) prompted a caller to ask us to explain this weather phenomenon. The ITCZ will appear as a band of clouds near the equator and is easily observed on satellite imagery. This band of clouds may extend for hundreds of miles in places, but will also be broken in to smaller segments as it circles the globe.
The ITCZ follows the sun and will move north during our summer and then further south during the northern hemispheric winter. This movement north and south through the year causes the wet and dry seasons so prevalent in tropical climates. It is referred to as a convergence zone because it is an area where the trade winds come together from both the northern and southern hemispheres. This convergence of the trade winds induces the rising motions that form the thunderstorms that dominate the ITCZ.
Spring 2009 will always be remembered for the record flooding and the heavy rain and snow that fell in March. Although both April and May finished well below average for precipitation, March was both the wettest and snowiest on record which in turn made the spring season wetter than normal. This past spring was the third snowiest on record with 28.3 inches being measured. All but 0.2 inches of that fell in March. Last year, we recorded 28.1 inches of snow during the spring season.
These past two years are the only back to back springs to make it into the Top 10 snowiest on record. Rain and melted snow added up to 7.05 inches of precipitation which made it the 26th wettest spring since 1881. Temperature-wise, the spring season finished 2.8 degrees below normal with an average temperature of 39.9 degrees. All three spring months were cooler than normal for the second straight year.
May 2009 finished 3.6 degrees below average making it our sixth straight month with cooler than normal temperatures. The long-term average May temperature is 57.4 degrees and this past month the average temperature finished at 53.8 degrees making it the 49th coolest May since 1881.
Not only did May continue our current stretch of cool weather, it also continued a long-term trend of cool Mays as ten out of the last fifteen Mays have been cooler than average with many being well below average. With the exception of 1998, most of the warmer than normal Mays during that stretch have been just slightly above the long-term average, so cool late springs have become the norm in the past decade.
May was our second straight month with below average rainfall. 1.62 inches of rain fell at Hector Int’l in May which was 0.99 inches below the 30 year average of 2.61 inches.