NewsChannel 8 Weather

A sure sign of spring arrives this Sunday: Daylight Saving Time. At 2AM this Sunday, March 14, most of us in the U.S. will turn our clocks ahead one hour and enjoy some extra daylight in the evenings and until the first Sunday in November, when we go back to Standard Time.

Back in November 2008, I wrote a blog about the background of Daylight Saving Time. Since we “spring ahead” this Sunday, I thought it would be “timely” to revisit this blog from the archives.

The time zones we use today in the United States (Eastern, Central, Mountain, Pacific, etc.) date only from the ratification of the Standard Time Act by the U.S. Congress on March 19, 1918. It wasn’t until 1929 that most nations in the world had adopted worldwide hourly time zones.

Daylight Saving Time, the practice of turning clocks forward an hour in the spring and then back to Standard Time in the fall, was first proposed by William Willett, a British industrialist, around 1905. The practice gained greater acceptance in Europe during World War I as a means of conserving coal, and was established in the United States in 1918 with ratification of the Standard Time Act.

Today, not every nation observes Daylight Saving Time. The practice is more commonly observed in the Northern Hemisphere, specifically in North America, Europe, the Russian Republics, and about half of the Middle East.

In the United States, Daylight Saving Time first began in 1918, but was repealed in 1919 and became a local choice. Daylight Saving Time was re-adopted nationally during World War II, and remained in effect until September 1945. It then, once again, became a local matter. The Uniform Time Act of 1966 once again attempted to standardize the practice of Daylight Saving Time, and set the time change dates as the last Sunday in April through the last Sunday in October, with local exemptions allowed.

During the energy crisis in the mid-70s, Daylight Saving Time start dates briefly started earlier in the year, but went back to April by the end of the decade. In 1986, the first Sunday in April officially was made the start date of Daylight Saving Time.

The most recent change to the dates of Daylight Saving Time occurred in 2005, when President George Bush signed into law the Energy Policy Act of 2005. As part of a Department of Energy study about the energy savings that could result from greater daylight, both the start and end dates of Daylight Saving Time were shifted to the second Sunday in March and the first Sunday in November, respectively. Congress reserves the right to revert back to the first Sunday in April and the last Sunday in October at the end of the study period.

As you can see, Daylight Saving Time has been a “timely” topic for more than 100 years — and counting.

After months of snow and cold, Mother Nature has finally given us a break with an early March thaw. But as the snow piles begin to melt away, our thoughts in the StormCenter turn to where all that melted snow will end up. The answer is easy… in area rivers. What’s not so easy is determining how the yearly snow melt will affect those rivers.

When predicting spring flooding, several factors are taken into account. They include the amount of rain that fell during the fall… how much snow fell during the winter and the water content of that snow… the frost depth… how fast the snow melts… and estimates for future precipitation during the melting process. These factors must be taken into account for every water basin in the region, because like a line of dominoes, what happens on one river system can have an impact on an adjacent systems.

The ideal conditions needed for keeping the flood threat low would include mild days with overnight lows below freezing. This allows a little bit of melt water to runoff slowly over time. 

We started down that ideal path last week, when afternoon highs reached the 30s and 40s, but overnight lows slipped into the single digits and teens. This week has been a different story. Not only have we seen above freezing temperatures at night and during the day, we’ve also had to deal with persistent light rain. This has allowed a large chunk of our snow cover to melt very quickly.

In the short term, this will affect smaller rivers, like the Trempealeau, Root, Black, Zumbro, and Kickapoo systems. In fact, the Kickapoo and Trempealeau Rivers will rise above flood stage by the end of the week. Provided we don’t get socked with heavy rain or snow, or an ice jam in those areas over the next week or two, any flooding will remain minor.

The Mississippi River is a much larger river and takes much more water to reach flood stage. When looking at the flood potential for the La Crosse and Winona areas, we have to look way up stream in parts of central Minnesota and parts of northern Wisconsin. These areas have seen quite a bit of snow. In addition, some of these areas received quite a bit of rain during the fall. As a result, there is some flood potential this Spring. However, the greatest threat lies from Hastings and points upriver. In the immediate La Crosse and Winona areas, it appears the river could reach flood stage, but only minor flooding is expected.

If you would like more information, the National Weather Service issues Spring Hydrologic Outlooks that deal specifically with spring flood potential. Here’s the link:  http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=arx&storyid=49311&source=0

The above statement was issued on March 5 and may be a bit outdated. However, a new outlook will be issued on March 26. 

Talk to you soon!

Now that it’s March, temperatures will begin warming rapidly and the mounds of snow (many still from our December blizzard!) rapidly will begin to shrink. It’s about this time that I begin getting requests for snow totals and how much snow we saw over winter.

Our snow season runs from July 1 through June 30, which means that seasonal snow totals are not based on a January through December calendar. This, in turn, means that monthly snow totals need to be added together to come up with a yearly total. Fortunately, this is easy to do!

Your first stop will be the home page for the La Crosse office of the National Weather Service. You can find this at www.crh.noaa.gov/arx. Go down the menu along the left side of the home page until you see the “Climate” section. Click on “Local”. This takes you to the Monthly Climate Data page. Click on the button labeled “Preliminary Monthly Climate Data” and follow the easy steps to access individual monthly climate summaries. Once a monthly climate summary opens in a new window, scroll down to the bottom of the data and look at the section labeled “SNOW, ICE PELLETS, HAIL.” The measured monthly snow total in inches is on the top line of this section.

To calculate the seasonal snow total, you’ll need to look at every month from July through June and add the measured snow totals together. To calculate snow totals for Meteorological Winter, you’ll need to add together the individual snow totals for December, January and February (Meteorological Winter starts December 1 and runs through the last day of February).

So far for our 2009/2010 snow season, we received no snow in July, August or September, 0.4″ in October, just a trace of snow in November, 24.9″ in December (most during the December 8-9 blizzard), 5.0″ in January, and 9.5″ in February for a total of 39.8″. We normally see about 7.2″ of snow during the month of March, and about 2″ of snow in April before average snow totals drop to 0″ in May. Our average seasonal snow total at the La Crosse Airport is about 45″, according to the Wisconsin State Climatology Office.

During Meteorological Winter (December 1 - February 28), 39.4″ of snow was measured at the La Crosse Airport. This is 8.9″ above normal, according to the National Weather Service, with both December and February having above normal snow totals and January having a below normal snow total.

All in all, we’re on track for a pretty average snow season — we’ll just need to keep an eye on what could be headed our way the rest of March and in early April.

Many of the questions I receive in the Storm Center relate to climate and weather data. What was the warmest day in 2007? How much snow fell last winter? When was that hail storm in early May?

Fortunately, many of these data are only a few key strokes away on the La Crosse National Weather Service Office’s Web site. The Web address for the La Crosse home page is www.crh.noaa.gov/arx or www.weather.gov/arx. The Web site menu is along the left side, with groupings of information (Current Hazards, Current Conditions, Forecasts, etc.). Go down until you see the heading titled “Climate” and click on “Local”.

This takes you to the Observed Weather Reports page, where you can access almanac data for days, months, years, and seasons along with significant weather events in La Crosse, Rochester, and other local areas.

Let’s say you want to know what the high and low temperatures were on August 18, 2006. There are four steps you’ll take to get these data.

First, select the button marked “Preliminary Monthly Climate Data”. This is a summary of every day in a specific month. Next, select the location you want — La Crosse, Rochester or Boscobel. Then, select the time frame. Unless you want the current month’s data, you’ll need to click on the button labeled “Archived Data.” Once you click this button, a drop-down menu showing available months and years becomes active. Scroll down to August 2006 (in our example). Finally, click the yellow “GO” button. A new window will appear with the monthly data for August 2006. It’s easy to see that the high and low for August 18, 2006, were 77F and 65F, respectively. You also can see that there was a Trace of rain (T) recorded this day at the La Crosse Airport and the average wind speed at the airport was 3.2 miles per hour. If you scroll to the bottom of the window showing the August 2006 data, you’ll see monthly summaries of temperature, wind, and precipitation.

Monthly climate data are available for up to five years in the past. You also can get Daily Climate Reports going back two months. Record Event Reports are issued as needed, and are generally available for the past six months. Monthly Weather Summaries are a more concise summary of monthly data, and are available for the past year. Finally, Regional Weather Summaries are issued several times a day, and have data for many observing sites across the region. These regional summaries are available for the past year.

If you need climate data for a larger area, like the entire United States or a longer period of time, your best bet is the National Climatic Data Center. Their Web address is www.ncdc.noaa.gov. The NCDC is the national clearinghouse for climate data. Most of the climate data you’ll need can be found by clicking on the window labeled “Weather/Climate, Events, Information & Assessments.”

There are other great sources for regional weather and climate data. The Midwestern Regional Climate Center specializes on the climate of the Midwest, including Wisconsin, Minnesota and Iowa. Clicking on an individual state takes you to that state’s climatology office. The Wisconsin State Climatology Office is located at the University of Wisconsin (about a block away from where I lived when I was a graduate student at UW). The Minnesota Climatology Working Group is located at the University of Minnesota, and the Iowa Climatology Bureau is located in Des Moines.

The Internet makes it easy to find weather and climate data — you just need to know where to look!

When the city of Vancouver made their bid to host the 2010 Winter Olympics almost a decade ago, they planned for every contingency — except Mother Nature.

Daytime temperatures above freezing in the weeks leading up to the opening ceremony played havoc with outdoor course preparation, and forced the Canadians to use helicopters to bring in snow to ensure a proper base for many of the skiing events. A steady drizzle didn’t help much, either.

As reported in the New York Times, “The Alpine skiing schedule has been scrambled at Whistler because warm weather and rain disrupted training runs and course preparation. At Cypress Mountain record warmth resulted in moguls built of hay bales and the snowboard cross course turning into a ribbon of white surrounded by rocks and dirt”.

Of course, when Vancouver was awarded the 2010 Winter Olympics in 2003, no one could have forecast that strong El Nino conditions would have developed in the Pacific Ocean. If they had, the International Olympic Committee may have considered another venue (such as the two runners-up: Pyeongchang, South Korea or Salzburg, Austria).

In fact, Vancouver is experiencing exactly the sort of winter meteorologists and climatologists expect when El Nino conditions develop in the Pacific.

Basically, El Nino conditions are characterized by unusually warm temperatures in the Equatorial Pacific Ocean. Since late November, a pool of abnormally warm water in the Pacific has existed along and south of the Equator from roughly 150 degrees West Longitude to the east coast of Australia (roughly 150 degrees East Longitude).

The effects of El Nino conditions on the climate and weather patters of North America, especially western North America, are significant. This is especially true during meteorological winter, which is defined by the National Weather Service as the period between December 1 and the last day of February.

Based on climatological records kept between 1948 and 2006, an El Nino winter in the western United States and the southwestern parts of Canada (which includes Vancouver) is characterized by lower snowfall and higher temperatures. In fact, an El Nino winter has far fewer days with two-inch or greater daily snowfalls and more days when the daily high and low temperatures are more than five degrees Celsius above normal. In addition, an El Nino winter also has significantly fewer days when daily high temperatures are below freezing, especially in western Montana and into Idaho.

After a mild, wet start, the weather in Vancouver might stay mild and wet. According to The Weather Underground Web site, Vancouver is expected to have high temperatures around 50F and overnight lows between 35F and 40F through Tuesday, February 23. Sunny skies are expected through Monday, with rain chances returning on Tuesday. Overall, not the best conditions for maintaining Olympic outdoor event venues.

At least the 2014 Winter Olympics in Sochi, Russia, ought to be free of El Nino or La Nina influences!