Monthly Archives: May 2021
Evidence of the presence of water in our atmosphere is ubiquitous.
Water occurs in the Earth’s atmosphere in all three of its phases — solid (snow and ice), liquid (rain and dew) and gas (invisible water vapor). As we begin to emerge from the recent cool spell and really enter spring/summer, we may begin to see more dew on the ground and on the windshields of cars in the morning. Continue reading
The first two days of this month had high temperatures of 87 and 84, respectively, and daily average temperatures (the average of the daily high and daily low) that were 15 and 19 degrees above normal.
In the next 12 days, the daily average temperature has been just shy of 6 degrees below normal. In fact, during that nearly two week stretch, nine days have had overnight lows in the 30s, including a streak of eight straight days from May 7 through Friday. The morning low on Tuesday was 30 degrees — notably cold and memorable for most of us, but only the 61st coldest morning in the first half of May in Madison’s history, far behind the all-time lowest of 19 degrees recorded on May 1, 1978. Continue reading
The National Ocean and Atmosphere Administration’s National Climatic Data Center (or NCDC) calculates the average weather conditions over a 30-year period for more than 7,500 locations in the United States.
A reliable estimate of an average requires at least 30 years. These 30-year averages are referred to as the U.S. Climate Normal. They provide a baseline that allows everyone to compare a location’s current weather to the average weather that location would expect to see — whether a particular day’s temperature is cooler or warmer than normal, or if a particular month is wetter than normal. Continue reading
Space contains tons of dust. When dust particles approach Earth, they can be captured by gravity and enter the atmosphere at very high speeds.
Particles with diameters larger than about 2 millimeters undergo very rapid heating through collisions in our atmosphere. As they heat up, they can produce a short-lived trail of light known as “shooting star.” Most dust particles entering the atmosphere are estimated to be much smaller than this and don’t provide a visible trail. Continue reading