Category Archives: Uncategorized

What is this upside-down icicle?

The accompanying photo was taken by Daniel Dettmers in the morning of February 4 on frozen Lake Kegonsa. The high on the previous day was 37°F. This caused puddles of water to sit on the ice of Madison’s regional lakes during the day. Tuesday morning’s low temperature was below 20°F with calm winds.  These are just the right conditions to form what are called ‘ice spikes,’ as shown in the photograph.

When water freezes, it expands and becomes less dense. Ice floats on water. But if the lake ice is thick, when puddles form on a warm day, they sit on the ice surface.  With the cold nighttime temperatures, the surface of the puddle freezes, trapping liquid water below. As the puddle freezes, it can leave a small hole in the surface of the ice. Continue reading

Category: Meteorology, Phenomena, Uncategorized

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What is the National Weather Service?

The National Weather Service, or NWS, is an office of the National Oceanic and Atmospheric Administration, NOAA, which sits in the U.S. Department of Commerce. The connection to the Department of Commerce is sensible – it’s estimated that one-third of the U.S. economy is sensitive to weather and climate.

The mission of the National Weather Service is to “provide weather, water, and climate data, forecasts, warnings and impact-based decision support services for the protection of life and property and enhancement of the national economy.” Continue reading

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How unusual was our dry and warm October weather?

Meteorologists often compare current temperature and precipitation measurements to “normal” values to interpret unusual weather. The weather data observed over the 30-year period between 1991 and 2020 are used to define “normal” or “average” weather. These normals are recalculated every 10 years. The normals are determined on annual, seasonal, monthly, daily and even hourly timescales. The maximum and minimum values also are tracked for each day of the year.

The weather that southern Wisconsin has experienced this October has been different from our normal October weather. Throughout most of October, we experienced very dry conditions. Prior to the storms that occurred on Oct. 30 and 31, the total precipitation across most of the state was less than 50% of the normal precipitation. This lack of precipitation throughout the month was alleviated during the final two days. Many areas in Dane County received over 3 inches of rain on Oct. 30 and 31. Continue reading

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Is our rainy summer finally drying out a bit?

Readers may recall we reported on the unusually wet nature of our late spring/ early summer about a month ago. At that time, Madison had recorded the wettest May 1-July 15 period since at least 1939 while averaging more than 2.5 degrees Fahrenheit above normal for that same period.

Another month has ticked away in this summer, and it has been a bit different than the ones that came before it. Through Aug. 15, Madison has recorded 1.73 inches of precipitation, which is 0.35 below normal. Ten of the first 15 days of the month had no precipitation at all and, from Aug. 7 to Aug. 13 we had a streak of seven straight days with no rain at all. That is now the longest dry streak since May 1. Continue reading

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What are good weather apps for smart phones?

Good weather apps for smart phones provide easy access to current weather and forecasts. Many apps tell you about the high temperature for the day and can provide an hour-by-hour breakdown of temperatures, chance and type of precipitation, air quality and other weather information.

Your device likely comes with an installed weather app, but consider exploring other apps. Apps that include live weather radar and any severe weather alerts for your area are valuable. They are useful for identifying precipitation and storm location and movement. Many include lightning flash locaters, too. Apps with current weather radar data provide useful information when you need to be outside and precipitation is in the area. Continue reading

Category: Meteorology, Uncategorized

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