Trivia Answer

The highest air temperature on Earth was recorded on September 13, 1922 in Al Aziziyah, Libya.  My question for you was: how hot is this record air temperature (in Celsius or Fahrenheit)?  If you guess anything below 130 degree's Fahrenheit, you were much too low!  The hottest air temperature ever recorded was 136F (58C)!  WOW that's hot!

September Weather Trivia

Did you know that the highest air temperature on Earth was recorded on September 13, 1922 in Al Aziziyah, Libya?  My question for you is: how hot is this record air temperature (in Celsius or Fahrenheit)?  Post your guess below and the answer will be shown here on Friday (Sept. 17th)!

First Frost?

Recently, I have had to include a mention of a frost or freeze in the forecasts for some of my clients.  While these areas were in the far northern reaches of Wisconsin and Minnesota, it still brings into light that the first fall frost is just around the corner.  The predictability of frost is very important in regards to the harvesting of crops and the lives of your outdoor flowers and plants.  So, when do we typically see our first frost of the season?

According to the NCDC (National Climatic Data Center), the first frost for most of Minnesota and Wisconsin occur during the month of September, while areas like the eastern side of Wisconsin (south of Green Bay), southern Wisconsin, the Mississippi River Valley of the Coulee Region, and most of Iowa see their first frost in the first two weeks of October.  Granted that these are just the climatic averages, with the given year we're in, when could we see our first frost?  Let's find out!

Below is a listing of various cities and towns in Wisconsin along with three dates behind each.  The first column of dates represents a 10% probability of a 32 degree temperature (and thus frost) for that location before or on that date.  The second column of dates represents a 50% probability of a frost before or on that date, and the third column of dates represents a 90% probability of a frost before or on that date.

So for a place like Wausau, WI, there is a 10% chance of frost before Sept. 21st, a 50% chance before Oct. 2nd, and a 90% chance before Oct. 13th for the fall of 2010.

I hope this will give you some idea when to expect the first frost of the season in your area.  If there's a place I left out that you would like information on, just post a comment and I will do my best to find the data!

Happy Autumn!

Early Autumn?

Many people around the area have noticed signs of the seasonal change already.  Some have seen geese heading south... others have noticed the trees loosing their leaves or beginning to change color.  I too have noticed hickory nuts have started to fall and barn swallows are mostly gone.  Is this a sign of autumn's early arrival?

Technically autumn arrives on September 22nd (the autumnal equinox) this year as the sun's direct rays on earth crosses the equator back to the southern hemisphere.  Traditionally you typically notice the seasonal changes more often in early to mid September, but with a La Nina currently in play in the eastern Pacific, seasonal changes could occur sooner.  Does this mean we'll have an early frost?  It is entirely possible.  We will have to wait and see.  If you want to follow how the autumn tree color change is coming across Wisconsin, please check out this website: http://www.travelwisconsin.com/fallcolor_report.aspx.

Cold, Snowy Winter Ahead?

That's right.  With all this heat and humidity lately, I thought it would be a good time to give your brain a mental cool down with some chilly thoughts about this upcoming winter.  Anyone who has been watching weather-related news the past few months may have heard of our recent transition from an El Nino to a La Nina in the equatorial Pacific Ocean.  During a La Nina event, the surface waters of the equatorial Pacific are 0.5 degrees Celsius or greater below normal.  Both El Nino and La Nina effect global weather patterns, and La Nina tends to impact our weather the most during the winter months when the jet stream is the strongest over the United States.  Typically, La Nina winters in Wisconsin (especially during moderate to strong La Nina events) tend to be colder than normal and wetter/snowier than normal.  The current La Nina is forecasted to become moderate to strong over the next several months.

The National Weather Service in Milwaukee, WI has recently done a study comparing La Nina event years to the normal climatic observations for both Madison and Milwaukee in southern Wisconsin.  The study concluded that both cities say below normal temperatures between January and March AND more snowy/wetter conditions during the same time frame.  This finding is very similar for the rest of Wisconsin as well.  Thus, for this winter, you could expect more snow to fall across Wisconsin with slightly cooler conditions, especially from January to March when La Nina events tend to impact the Midwest the most.

Wet & Wild Summer

The talk around town has definitely been all the rain we've been getting this summer!  The wet conditions have prevented farmers from being in the fields,  caused area creeks and rivers to run high or out of their banks, and have led to optimum breeding conditions for mosquitoes.  This may have you wondering, how exactly does this summer compare to normal as far as precipitation?  Well, below is listed some Wisconsin cities and the precipitation they've seen so far this year, along with the normal climatological values for precipitation in the same time frame.
          City                            2010            Normal        Departure

1. La Crosse                17.20"            9.37"           7.83"
2. Milwaukee               18.16"            8.18"           9.98"
3. Madison                  17.38"            9.10"            8.28"
4. Green Bay               17.11"            7.83"            9.28"
5. Wausau                   16.66"            9.42"            7.24"

As you can see, most of these areas have seen almost twice the normal amount of rainfall so far this summer!  In fact, La Crosse is currently having it's 2nd wettest summer through 7 A.M., August 8th and it's 12th wettest summer on record. If La Crosse receives another 3.12" of rain by the end of August (0.11" of rain already fell this morning after the climatological data came out, so its is now down to 3.01"), 2010 will go down as the wettest summer ever in the city!

So now with saturated soils all across the state, any rain that does fall over the area will quickly run off.  This is likely to cause some flooding issues along creeks and river beds.  It could also trigger some mudslides, especially across the hills and bluffs of Western Wisconsin.  That means that during this time of very wet weather, keep an eye on your surroundings, especially if you live near a body of water or along a hill side.  Take precautions now to prepare for such events!

Aurora Borealis - The Northern Lights

Unfortunately the northern lights were a no show last night.  There just was not enough energy to produce them this far south in the states (at least southwestern Wisconsin that is).  However, like I promised, I will explain what causes these atmospheric light shows!

It all starts 93 millions of miles away on that glowing fireball we call the sun!  Our sun is constantly emitting charged particles, byproducts of its thermonuclear reactions.  Together, these particles form what is known as a solar wind which travels away from the sun at speeds up to a million miles per hour!  At its top-end speed, a solar wind could reach Earth in as little as two or three days!  Normally, the Earth's magnetosphere (or it's magnetic field) deflects the normal solar wind that comes our way every day.  However, when there is a solar flare or a coronal mass ejection from the sun, much similar to Sunday's event, the solar wind is much, much greater!  This increase in energy disturbs the normal balance between the solar wind and the Earth's magnetosphere.  As a result, electrons and protons within Earth's magnetic field are accelerated and travel down magnetic field lines to Earth's poles.  Here, these charged particles collide with atoms and molecules of the upper atmosphere (typically O, N, and N2) and actually pass their charge onto the atoms and molecules, forming excited states of these gases.  As these gases release the energy and return to their normal state, they give up the energy in the form of light - producing the aurora!

You may have noticed that auroras have various colors as well.  The specific colors we see in an aurora all depend on which atmospheric gas is stuck by the energetic particles.  Oxygen is primarily responsible for two different colors, a green-yellow light and also a more rare deep red light.  Nitrogen, on the other hand, can produce either a blue light or a purple-reddish light, typically seen at the border or edges of an aurora.

I hope this answers some questions... and it may have you coming up with more!  Just ask, and I will try to answer any questions about auroras that you field my way!