The Weather Guys

Is there a “State Tournament Snowstorm” legacy?

Posted on March 21, 2017 by WeatherGuys Editor

WIAA Division 1 state tournament semifinal at the Kohl Center in 2017. Only four times in the last 60 years has the tournament been free of snow. (Photo credit: John Hart, State Journal)

A persistent anecdotal piece of weather lore around Madison is that the WIAA’s boys state basketball tournament is always accompanied by a snowstorm.
With the help of Edward Hopkins at the State Climatologist’s Office, we looked into this perception with cold, hard data.

Hopkins provided the daily snowfall totals for every March since 1950. We identified the days on which the boys’ tournament was played in Madison (we chose the boys tournament only because the record was longer).

The results are very interesting. It turns out that only four times in the past 60 years have the approximately five-day-long tournament been free of snow — that is, only about 6 percent of the time does no snow at all fall during the duration of the tournament.

Most of the remaining 63 “snowy” tournaments were characterized by days on which at least a “trace” amount fell (not enough to measure, but enough to say it snowed). A few had days on which 1 or 2 inches fell.

The all-time record amount during the tournament was 12 inches on March 18, 1971 (followed by 2.5 inches the next day).

Only seven tournaments (10.4 percent) had a single day on which more than 3 inches of snow fell.

Such conditions are roughly equivalent to those necessary for issuance of a snow advisory by the National Weather Service.

Thus, though snow is almost always in the air during tournament time (this year there were traces of snow on Thursday and Friday), it appears that less than one in eight tournaments have actually been accompanied by a snowstorm.

— Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) at 11:45 a.m. the last Monday of each month.

Category: Meteorology, Seasons

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Is carbon dioxide a major contributor to global warming?

Posted on March 13, 2017 by WeatherGuys Editor

EPA Administrator Scott Pruitt, who recently stated on CNBC that he does not believe that carbon dioxide is a primary contributor to global warming, putting him at odds with scientific consensus and his own agency. (Photo credit: Melissa Phillip, Houston Chronicle)

The Earth’s atmosphere is a mixture of many different gases. Several of these gases are known as “greenhouse gases” because they share the characteristic of being excellent absorbers of infra-red radiation.

Such gases absorb radiation emitted by the Earth that would otherwise escape to space and cool the planet. Upon being absorbed, these gases re-emit a fraction of that energy back downward to the surface, keeping the planet warmer than it would otherwise be. In fact, our Earth would have an average temperature of about zero without these greenhouse gases.

The average temperature of the planet is 59 degrees, dramatically demonstrating the warming effect of these greenhouse gases.

Among the collection of greenhouse gases, carbon dioxide (CO2) is the one that has attracted the most attention with regard to global warming. This is likely because CO2 is a by-product of burning fossil fuels, the acknowledged predominant energy source for our nation’s and the world’s economy.

In the last 100 years, the accelerated use of fossil fuels has led to an increase in the CO2 concentration in the atmosphere from 300 to 400 parts per million (400 molecules of every one million are now CO2). The current concentration far exceeds anything the Earth’s atmosphere has experienced in at least the last 800,000 years.

Being a greenhouse gas, the more CO2 there is in the atmosphere, the greater the warming effect.

This basic physical fact is indisputably true. Thus, to hear the new administrator of the Environmental Protection Agency (EPA) assert that CO2 is not a “primary contributor” to global warming, as he did last week, represents a stunning display of willful ignorance.

It seems unlikely that Americans would tolerate the surgeon general of the United States suggesting that smoking does not cause cancer. Neither should we accept this recent statement by the EPA chief.

— Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) at 11:45 a.m. the last Monday of each month.

Category: Climate, Meteorology

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How did this winter compare to others?

Posted on March 7, 2017 by WeatherGuys Editor

Now that the traditional winter season (December, January, February) is over, we can consider how this season stacked up against the preceding 69 winters in terms of its hemispheric intensity.

One way to measure this intensity is to consider the areal extent of air colder than 23 degrees at about one mile above the ground. For several years now, at UW-Madison we have been calculating this areal extent each day and, using those daily values, can calculate a seasonal average.

This year the season ended up being the 13th warmest in the last 69 cold seasons.

Evidence like this makes two points very clear. First, the evidence supports the scientific consensus that the planet is warming in a systematic way and that this warming is most likely a result of changes in the chemical composition of the atmosphere brought on by industrialization.

Second, there has been no “pause” in the warming trend the Earth has been experiencing in the last 100 years as is suggested by global warming skeptics.

We are currently examining the intensity of winters on a more regional basis using the same metric and will report on those results soon.

— Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) at 11:45 a.m. the last Monday of each month.

Category: Meteorology, Seasons, Uncategorized

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Do atmospheric rivers occur over Wisconsin?

Posted on February 27, 2017 by WeatherGuys Editor

Total precipiatable water measured by water vapor sensors on satellites depicting an atmospheric river from February 2017. Credit: CIMSS

An atmospheric river is a term used to describe a relatively narrow region in the atmosphere that transports water vapor outside of the tropics northward.

They are typically a few thousand miles long and a hundred miles wide. There can be three to five of these “rivers” at any time covering the hemisphere.

Atmospheric rivers are apparent in satellite images and are often in the vicinity of fronts over the oceans. They transport large amounts of water. A common atmospheric river is one that transports water vapor from Hawaii to North America, sometimes nicknamed the “pineapple express.”

While these atmospheric rivers are made of water in the gas form, or water vapor, they can carry as much water as a dozen Mississippi Rivers. The features can transport water into storms and result in extreme precipitation events which cause severe flooding in western coastal regions of the world, including the West Coast of North America.

Much of the precipitation and resulting flooding occurring on the West Coast is from water vapor transported across the Pacific Ocean by these rivers of water vapor. While some of these events lead to flooding and mud slides, most precipitation events simply provide beneficial precipitation important to the region’s water supply.

Much of the water vapor transport to Wisconsin comes from the Gulf of Mexico and not the tropical Pacific Ocean. Water vapor transport by atmospheric river coming from the Pacific Ocean has to flow over the Rocky Mountains, where much of the precipitation falls out.

Steve Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) at 11:45 a.m. the last Monday of each month.

Category: Uncategorized

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How does this current February warm spell rank?

Posted on February 21, 2017 by WeatherGuys Editor

A frozen lake is a public good for all.
Photo Credit: John Hart, WSJ

It’s no secret we have had some amazingly warm weather the past few days. After reaching 60 Fahrenheit Friday February 17, the temperature soared to 62 F Saturday in Madison, breaking the previous record for the date (57 F) set in 1981.

In Milwaukee, the record-shattering was even more extraordinary as the Saturday high of 67 F broke the old record for the date – set in 1877—by 10 degrees! In fact, Milwaukee’s high of 67 F was just one degree short of its all-time February record of 68 set on Feb. 11, 1999.

Madison’s 62 F on February 18 was only two degrees shy of its all-time monthly record of 64 F set on February 25, 2000.

These are clearly exceptional temperatures!

Combining Friday and Saturday’s warmth with what appears likely in the short-term forecast, both cities may be in the running to record another unusual meteorological event by Wednesday of this week.

It is quite rare for six consecutive days in February to have high temperatures of at least 50 F. This last occurred in Milwaukee in 2000 while the wait has been much longer in Madison – not since 1930!

The expansive ridge of high pressure that is responsible for our warm spell appears reluctant to move so we may well see the longest February warm streak in Madison since Herbert Hoover was living in the White House.

In addition, it is not inconceivable we could set a daily record on every one of those days. It is a welcome respite from winter and should serve as an encouraging reminder of what is to come.