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Today will mark the 16th day in a row with temperatures above average.  So far this winter we have seen only 10 days come in below average.  That means that 81% of days this winter have been above average.  

The National Weather Service in Chicago has crunched some more mild winter numbers.   This winter now ranks among the top ten winters with the number of days with highs of 40º or more.  The winter of 2011-2012 now ties the winter of 2001-2002 with 35 days of highs of 40º or more, the ninth most 40º highs for a winter on record.   This winter also ties 6 other winters with 10 days with highs of 50º or more, the eight most 50º highs on record for a winter. 

Colder weather is coming later this week though.   Highs Friday and Saturday will probably not get out of the 20s making it the coldest air we have seen in nearly three weeks.  While we have made it through this winter relatively unscathed, that is not the case in Europe.

 The Serbian government announced a state of emergency on Sunday (see photo above) due to the extreme cold.  London's Heathrow, Europe's busiest airport, had to cancel more than 40% of its outgoing flights on Sunday as more than 6 inches of snow fell in parts of England overnight and temperatures dropped well below freezing.  Snow covered the Eiffel Tower in France over the weekend.  The death toll from the harsh winter weather is climbing.  According to the Chicago Tribune, "nine more deaths from freezing temperatures were registered in Ukraine overnight, emergency services said, taking the death toll to 131 from a nine-day cold spell, the most severe in the country for six years with night temperatures down as low as minus 33 Celsius (minus 27 Fahrenheit) in parts."  The death toll across Europe climbed to 280 over the weekend.

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The ground hog had his day yesterday and his bold prediction of six more weeks of winter doesn't seem like much of a threat.   Most of us could handle six more weeks of the kind of winter we have seen so far.  According to Illinois State Climatologist Jim Angel the average temperature for December/January was 33.4º for Illinois, making it at the 6th warmest December/January period on record going all the way back to 1895.  So Arctic air has been elusive this winter.  There have only been ten days with temperatures below average. Snowfall has been scarce also.  At O'Hare we would normally have 21.5" of snow by now but so far this winter we have picked up just 13.19".

We put our number crunchers to work to see if a a warm winter normally is followed by a hot summer.  We looked at the past 83 winters at Midway for consistency's sake.  Of those 83 winters, 26 had above average temperatures for the months of January and February (like this winter).  15 of those summers (months of June, July & August)  that followed had temperatures above the average of 73.2º. 

We then narrowed it down to summers that followed winters that were well above average.   This winter has been +6.8º above average.  There were four winters at least that warm and three out of the four summers that followed were also warmer than average.

         Year                     above/below avg.

   summer of 1931                   -0.5º

   summer of 1982                  +2.8º

   summer of 2001                  +3.0º

   summer of 2006                  +0.9º

So in conclusion, statistically speaking, there appears to be a correlation between a warm winter and warmer than average summer.  58% of summers following warmer than average winters were also warmer than average. 75% of summers that followed the four warmest winters  (given it is a small sample size) were also warmer than average.

Special thanks to Frank Wachowski & Richard Koeneman for their help.

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Thursday is Groundhog Day so I wanted to take this opportunity to launch a preemptive strike by whacking the weasel with some facts about his forecasts.  Most meteorologists dread Groundhog Day. Bill Murray's portrayal of a television weatherman in Groundhog Day and his attitude about the day was spot on.  Woodstock (see photo above) is celebrating the 20th anniversary of the film crew shooting the classic comedy in and around their town.   Should be good fun but still, meteorologists and weathermen everywhere shun the hoopla surrounding February 2nd. We are expected to act as the groundhog's spokesperson and explain the archaic shenanigans of a bunch of old men with large top hats who enjoy pulling a rodent out his hole, thrusting him in the air and making proclamations about whether or not winter will continue.  This will be my 26th Groundhog Day as a broadcast meteorologist so I have heard just about every joke there is regarding the day.

Stam Zervanos, a professor emeritus of biology at Pennsylvania State University, Berks College, has crunched the numbers and they aren't very good if you are a groundhog.   He estimates the groundhog's forecast is accurate only 39% of the time.  Canadian groundhog's forecasts are even fuzzier.  According to Encyclopedia Canada, groundhogs up north are only 33% accurate. We might as well ask a giraffe for stock picks, he could probably be just as accurate.

So Punxsutawney Phil is a punk when it comes to weather forecasting.   In his defense, long range forecasting is tricky at best.   Can you recall anyone last fall calling for a warm winter with less than average snowfall?  For a more scientific explanation behind this winter's weather, check out an excellent article from ChicagoMag.com.

So if you see me or any of my meteorological brethren on Thursday please keep the Groundhog Day jokes to yourself.   If you can't resist, I may have to share some hot stock picks I heard from Jerry the giraffe.  

There is at least one good use for groundhogs.   Click here for a link to a recipe for Woodchuck Stew. 

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Keep in mind snow lovers that it could be even worse.   Here is a list of cities that have seen an even greater disparity between actual snowfall and what they normally see during a typical winter to date.

                         Snowfall so far this winter        Normal       % of normal

Boston                     7.8"                                   22.4"            35%

Minneapolis             14.9"                                  32.8"            45%

Green Bay               15.3"                                  29.5"            52%

Des Moines             10.1"                                  19.4"            52%

Detroit                     15.6"                                  22.9"            68%

The snowpack has faded fast this past week.  As of yesterday, 28.8% of the lower 48 has snow cover with an average depth of 3.3".   That is down from a week ago when 42.6% of the lower 48 had snow cover with an average depth of 4".

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Two more tornadoes yesterday (1 in Mississippi and 1 in Louisiana) brings the preliminary total for the month of January to 70 already.  The vast majority of those tornadoes struck the deep south.  The last three years the US has averaged 17 tornadoes during the month of January. This is now the 3rd most active start to a year in terms of tornadoes since 1950.

While tornadoes in January are rarer for northern states, Illinois is certainly not immune to twisters during this normally cold month.  The state has seen about 30 tornadoes during the month since 1950.   The bar graph below shows the peak months in Illinois are April, May and June.

One noteworthy January tornado because of its location and video documentation, occurred on January 7th, 2008.  It was the most northernmost tornado to hit Illinois in January, touching down in Harvard.  A camera mounted on the train shows how powerful tornadoes (even January tornadoes) can be as the cars of the train are swept of the track by the ferocious winds.

Illinois state climatologist Jim Angel has a summary of Illinois' January tornadoes on his blog.  The map below shows where January tornadoes have touched down across the state.  Notice the lack of tornadoes in the immediate Chicago area but the otherwise random distribution of tornado tracks. 

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Powerful thunderstorms whipped up tornadoes early this morning in the south.   There were at least 19 reports of tornadoes according to the Storm Prediction Center.  There were also more than 100 reports of strong/damaging winds and nearly three dozen reports of hail.

The National Weather Service relies on these reports from observers for "ground truth" or verification of what is actually occurring at the surface.   If you are interested in becoming a trained severe weather spotter, now is the time to sign up for training sessions offered by the Chicago National Weather Service office.  Classes begin in February and last through early April.  Check out the NWS website for dates and times.

Speaking of severe weather and tornadoes specifically, the USA Today has story today detailing the upgrade that is slated for all 160 National Weather Service Doppler radars nationwide.  The upgrade means all NWS radars will become "dual-polarization" or "dual pol" radars.  Here is how the NWS explains the upgrade:

Currently, National Weather Service Doppler radars are horizontally polarized radars, meaning their pulses are sent out with a horizontal orientation, which is ideal for sampling raindrops which tend to acquire a flattened appearance as they fall through the air.  However, by adding a vertical polarization, more information can be gained about the shape of the hydrometeors falling from the sky, and will make it easier for meteorologists to discriminate between rain, hail, snow and sleet.

So far twenty dual-pol radars have been installed, Chicago being one of the first.  109 more upgrades are planned by the end of this year and the entire $50 million project should be completed by spring of 2012.

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The coldest morning of the season for some of us will be followed by the biggest snow of the season so far late today and tonight.   Here are the coldest lows we saw this morning:

-5 Harvard

-3 Kenosha

-2 Island Lake

-2 Union

So we go from bitter cold to big snow within 12 hours.   If our forecast of 4-8" pans out, it will be the biggest snow we have seen since the Groundhog's Day Blizzard last February.

Winter is walloping us today.   I thought it would be a good time to share some websites that will help you survive another Chicago winter.

Here they are-

http://www.nws.noaa.gov/om/winterstorm/winterstorms.pdf

The National Weather Services preparedness guide for winter storms.

http://www.state.il.us/iema/disaster/pdf/iema333_winter_storm_preparedness_guidebook.pdf

Illinois Emergency Management Agency's winter weather preparedness guide.

http://www.crh.noaa.gov/lot/?n=wxterms

The National Weather Service Chicago's weather terminology page.

http://www.aaaexchange.com/main/default.asp?categoryid=3&subcategoryid=55

Winter driving tips from AAA.

http://www.cityofchicago.org/city/en/depts/mayor/snowportal/chicagoshovels.html

City of Chicago's "Chicago Shovels" site to track city plows and lend a helping hand to neighbors.

http://wrc.gettingaroundillinois.com/pages/wrc.htm

Current road conditions across the state.

Stay safe and enjoy the snow!

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Don't like our weather as of late, just wait...

In the short-term the forecast is calling for some of the toughest winter weather we have seen so far this season but in the long-term it's another story.   Temperatures will come crashing down tomorrow and could dip to near zero or just below by Thursday night.  In other words a reversal of what you see in the photo above from Trib Photo Nation.

In just the last week alone the lower 48's snow cover nearly doubled from 15.8% (average depth 1.5") on January 10th to 32% (average depth 1.5") yesterday.  Notice in the graphics below the greatest changes that have occurred over the last week have been in the Northern Plains and Midwest.

The next round of Arctic air tomorrow could squeeze out a dusting but Friday's storm could be more potent.   Models are hinting at as much as 3 to 6" Friday afternoon into Friday night.

The snow cover will begin melting off by at least Monday as temperatures bounce back to above average levels.  The longer range forecasts are indicating a fairly good chance we will see a mild end to the month of January.

The 6-10 day outlook from the Climate Prediction Center (above) shows a 70% probability we will see warmer than average temperatures next week.   The 8-14 day outlook looks similar and takes the forecast out through the end of the month with temperatures expected to remain above average overall.

No rest for the weary when it comes to hurricane hunter jets.  After a fairly active hurricane season last year with 19 tropical storms, 7 hurricanes, and 3 major hurricanes, at least one hurricane hunter jet is being repurposed to gather data on incoming winter storms along the west coast. A NOAA Gulfstream IV-SP "Hurricane Hunter" jet will be busy this winter flying through the skies over the pacific to monitor storms as they develop and threaten the United States.  The jet will fly around 45,000 feet while underneath, at lower altitudes, a U.S. Air Force Reserve weather reconnaissance plane will gather data to help form a more complete, three dimensional picture of the approaching storms.   It's a far cry from hunting hurricanes and a long way from home for the aircraft that is based at MacDill Air Force Base in Tampa, Florida.

Speaking of winter storms and winter weather...

Do you know the difference between a winter weather advisory and a winter storm warning?  NOAA has a guide to the winter weather terminology to help you decipher winter forecasts.

Finally, The Illinois Department of Transportation offers a website to to help you navigate through the snow, slush and sleet this winter. The site, http://www.gettingaroundillinois.com/, gives road conditions and construction reports among other valuable information for Chicago commuters.

I expect traffic on that site to spike tomorrow morning as we anticipate rain changing to snow early Tuesday.  It could be a slick start on Tuesday.

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Snow blowers and lower backs will be getting a workout today as we dig out from yesterday's storm, the biggest snow of the season so far. Most areas picked up about a half foot of fresh snow.  O'Hare had 4.7" through midnight making it the most snow in a single day since 6.6" fell on February 2nd, 2011.   This storm brings our total for the winter to 6.6" which is still less than half of what we normally expect through this point of winter.

Here are some snowfall totals from yesterday's storm:

7.0" Lake Zurich

6.8" Crest Hill

6.2" Niles

6.2" Elburn

6.1" McHenry

6.0" Romeoville

6.0" Bolingbrook

6.0" Batavia

5.7" Midway

Seems like we have now kick started winter.   Three more shots at accumulating snow coming in the next 5 or 6 days.   We expect just a dusting late tomorrow, tomorrow night but more could be on the way Tuesday and again late Wednesday into Thursday next week.

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