There is no denying that we live in a cold dominated climate. We certainly have some beautiful weather during our warm season, yet, because the cold lasts far longer than our brief summers, thoughts of winter are never far away. Because of this, several people have inquired about the upcoming winter season. With a La Nina already developed in the Pacific Ocean, most of these inquiries are fearful of another colder than average winter.
Indeed, at this point, the winter could easily turn out to be our 4th consecutive cold winter based on a number of variables besides the La Nina in the Pacific. But that possibility is still several months away, so no matter what the upcoming winter may bring, we still have another two to three months of very nice weather to enjoy.
So for me, my focus is enjoying the great weather that often comes during August and September in this area and I will worry about winter when winter is here.
If you are an early riser like myself, or are out enjoying the late evenings, you have likely noticed that the sun is rising later and setting earlier then it did a few weeks ago. Since the Summer Solstice in June, Fargo Moorhead has lost over 30 minutes of daylight in the morning and a bit less than 30 minutes in the evening.
Our earliest sunrise in June occurred at 5:32 AM and our latest sunset time was at 9:26 PM. We are currently losing about 3 minutes a day of sunlight and will maintain a lose of either 3 or 4 minutes a day right through early December when that pace will slow slightly as we approach the Winter Solstice. Our sunrise and sunset times vary slightly from year to year, but in December we will see our sunset times bottom around 4:38 PM in the middle of December and our sunrise times will occur around 8:12 in the morning.
The first half of July continued our recent trend of this area experiencing above average temperatures. The average temperature through the first 17 days of July has been 72.7 degrees which is nearly 3 degrees above average. In fact, this month, so far, ranks as the 2nd warmest July this century, granted, that is only 10 years, but yet still confirms that recent temperatures have been warmer than those found in recent summers.
Although this month, to this point, is the 2nd warmest of the past ten years, historically, it only ranks as the 28th warmest since 1881 which also shows how cool most of our summers have been during our current wet cycle. Speaking of rain, Fargo Moorhead recorded 1.94 inches of rain from July 1-17, which is very close to the average through that point in the month. Although, most locations both south and east of Fargo Moorhead have recorded well above average rainfall so far this month.
Among the storm reports from the severe weather last week was some incredibly large hail that fell in portions of south central North Dakota. The hardest hit area was in Sioux County where golfball to softball sized hail was observed. At the Prairie Knights Resort a few hailstones were measured to be 5 inches in diameter which tied the record for the largest hailstone observed in North Dakota. The last time such a large chunk of hail was seen in North Dakota was on August 3, 1969 in Mercer County.
Those hailstones were large enough to smash and go through windshields and even puncture and completely go through some roofs. Needless to say, damage was significant to buildings, vehicles and to area crops. Plus, if that was not enough, that same area was also hit by wind gusts estimated to be near 70 mph damaging additional structures and crops that were missed by the hail.
The residents of Fargo Moorhead and much of the rest of the area did not know it at the time, but on this date in 1936 the most intense heat wave since records began was about to end. July 18, 1936 was the 15th straight day with a high temperature at or above 90 degrees. Included in that streak were 8 straight days, July 6-13, with a high temperature exceeding 100 degrees.
No other heat wave in the record books comes close to what occurred in July 1936. Although the streak of 90 degree days came to an end on July 18, 1936, it did not exactly turn cool as 15 more 90 degree days were recorded in the next 24 days. Although, no more 100 degree weather was experienced for nearly two months, things changed on September 22 when the high temperatures soared to 101 degrees, which to this day, still stands as the latest 100 degree day on record.
Today is climatologically speaking the warmest day of the year in Fargo Moorhead. The current 30 year average high and low for today is 83 and 60 degrees and it is the only day that the averages are that high. Tomorrow, the average high will remain at 83, but the average low will drop to 59 degrees. The average low temperature of 60 degrees occurs on only three days of the year, July 15, 16 and 17, but on July 15 and 16 the average high is 82 which makes today unique among the other days of the year.
If you are fretting that the average temperatures are now starting to decrease, you need not worry. You see, the average High and Low will be 83 and 59 degrees starting tomorrow and remain the same for the next 25 days. Therefore, although we may have reached the technical peak of our warm season today, the real decline in our average temperatures will not have any noticeable drop in the next month.
Getting caught outdoors as it begins to rain, especially without an umbrella, is probably something most of us would prefer to avoid. But when this does happen, how wet you get will be in many ways determined not only by the intensity of the rain, but also the size of the raindrops falling from the cloud overhead.
The size of the raindrops falling from a particular cloud is determined by two principle factors; the intensity of the updraft in the parent cloud and the size of the condensation nuclei that the drop originated from. Strong updrafts with in a storm are capable of keeping raindrops in the cloud from falling to the ground, allowing them to grow larger. This is also true of hailstones and some raindrops are just small hailstones that have melted before reaching the ground.
This is turn helps illustrate that raindrop size is also determined by the mechanisms that caused the raindrop to form in the first place.
We are entering what is generally considered by many to be the dog days of summer. The name goes back to the ancient cultures from Egypt, Greece and the Romans and in many ways carries on to this day. It is referred to as the “dog days” because the star Sirius, the brightest star in the sky, begins to rise along with the Sun during this hottest period of the year.
Sirius is called the “dog star” as it is part of the constellation Canis Major, which many ancient cultures associated with being a dog following Orion, the great hunter in the night sky. The Romans referred to the 30 day stretch from July 24 through August 24 as the “dog days” and in modern times that has been translated into the 40 warmest days of the year from early July to mid August.
If we use that definition then July 4 through August 12 would be the dog days in Fargo Moorhead.
If you look carefully at the location of the world’s deserts, you will notice that most of them are located near 30 degrees north and south latitude. This is part of the global circulation pattern induced by the differences of solar energy received around the planet. A simple model of global wind fields would have an overall area of low pressure near the equator. This rising air eventually sinks near 30 degrees north latitude where areas of high pressure dominate.
This sinking motion inhibits cloud formation and also increases temperatures through compressional warming causing large expanses of dry sunny regions. That sinking air then partially returns to the tropics, but because of the rotation of the planet, it is deflect to the right causing the wind in the tropics to be from an easterly direction.
This is turn is why hurricanes move generally from east to west. That flow pattern in the tropics is referred to as the trade winds, or trades.
Last week from Thursday through Saturday, the official low in Fargo Moorhead was at or above 70 degrees. That was the first time since early July, 2005 that Hector Int’l recorded such a streak. Plus, because of the cooler summers we experienced the past two years, those 70 degree low temperatures were the first recorded locally since July 31, 2007.
Since 1881 Fargo Moorhead has averaged 3 days a year with a low temperature at or above 70 degrees. The highest number during any year was back in 1936 when 15 such days were observed. As recently as 2007, eight such days were recorded which was the most since the summers of 1995 and 1988 when nine 70 degree mornings were observed. Considering how early in the summer it is, the odds favor this area having additional mornings with low temperatures in the 70s, a stark contrast to the chilly conditions we experience last summer.