First Major Snow for Some in Illinois

The recent winter storm dropped snow across western and northern Illinois. The first figure is a screenshot of a product found at http://www.srh.noaa.gov/ridge2/snow/

The Davenport, IA, NWS office provided a map with more detail on the heaviest snowfall amounts in northwestern Illinois (second figure). The heaviest snow in Illinois was 11 inches at Apple River Canyon in far northwestern Illinois.

Snowfall map for the period ending on the morning of December 21, 2012. Click to enlarge.
Snowfall map for the period ending on the morning of December 21, 2012. Click to enlarge.
Snowfall map for December 21, 2012, produced by the NWS office in Davenport, IA. Click to enlarge.
Snowfall map for December 21, 2012, produced by the NWS office in Davenport, IA. Click to enlarge.

New January and Winter Forecast for Illinois

The Climate Prediction Center of the NWS has released their latest forecast for January and for the series of 3-month periods starting with January-March. The forecast for January (first map, top panels) in Illinois is non-committal with “equal chances” of above, below, and near-normal temperature and precipitation across the state. We are sandwiched between wetter than normal areas to the north and south of us.

The forecast is a little more interesting for the 3-month period starting in January (first map, bottom panels) with much of the southern two-thirds of Illinois in an increased chance of above normal precipitation. Far southern Illinois has an increased chance of above normal temperatures.

The seasonal temperature forecast for April-June (second map) shows an increased chance of above-normal temperatures across Illinois and much of the US. Their seasonal precipitation forecast for April-June (not shown) calls for equal chances of above, below, and near-normal precipitation. The seasonal temperature and precipitation forecast for July-September are non-committal with equal chances of above, below, and near-normal conditions during that period.

The seasonal forecast for drought shows expected improvement in drought in northern Illinois (third map). They expect drought to continue in western Illinois with only limited improvement in the next three months. They expect drought to continue to the west of Illinois with limited improvements in parts of Missouri, Iowa, and Minnesota.

You can see all the Climate Prediction Center forecasts on their website: http://www.cpc.ncep.noaa.gov/

Climate Prediction Center forecast for January and January-March. Click to enlarge.
Climate Prediction Center forecast for January and January-March. Click to enlarge.
Temperature forecast for April-May from the Climate Prediction Center. Click to enlarge.
Temperature forecast for April-May from the Climate Prediction Center. Click to enlarge.
U.S. seasonal drought outlook from the Climate Prediction Center. Click to enlarge.
U.S. seasonal drought outlook from the Climate Prediction Center. Click to enlarge.

Drought and Barge Traffic on the Mississippi River

On Saturday, the US Corps of Engineers began releasing water from Lake Carlyle (east of St. Louis), which flows down the Kaskaskia River into the Mississippi River near Thebes. They kept the water level higher than usual on Lake Carlyle this fall, in anticipation of this move. As the article below states, it’s a short-term measure.

Corps Releasing Water from Carlyle Lake to Secure Mississippi River Traffic (USA)

And for you drought history buffs, during the 1988 drought Governor Thompson (Illinois) suggested increasing flow out of Lake Michigan and down the Illinois River to aid in navigation on the Mississippi River. Stan Changnon discussed this in an article on the 1988 drought and it’s impacts on the barge and railroad industries. The abstract of that article summarizes the situation:

The drought of 1988 rated as one of the nation’s worst in the past 100 years, resulting in a myriad of impacts and responses. A notable, largely unexpected impact involved stoppages of barge traffic on the lower Mississippi River during June and July, a result of shallow areas produced by record low flows and shoaling. The barge industry hauls 45% of all bulk commodities (grains, coal, petroleum) shipped in the central United States. The low flows were a result of the unusually large areas extent of drought conditions across most of the Mississippi Basin, which comprises 40% of the continental United States. Most 1987 months had been relatively warm and dry, minimizing moisture in the soils and shallow ground water. Then deficient snowmelt (due to low winter snow-falls) and record low spring 1988 precipitation combined to produce the record low flows along much of the Mississippi River.

Most responses to the drought came in a crisis mode and included concentrated dredging to open channels, government enforced reductions in barge loads and in numbers of barges per tow, tripled barge shipping rates, and shifts in transportation modes. The barge industry suffered a 20% income loss. The total losses to the barge industry coupled with higher costs for shipping were $1 billion. The Illinois Central Railroad, which parallels the major blocked waterways, used a climate prediction to anticipate the low flows 3 months in advance. They leased additional cars to help handle the increased shipments transferred from barges and made a sizable profit. A response proposed by Illinois and shippers—a temporary increase in the water diverted from lake Michigan to raise the levels on the lower Mississippi River—was met with strong objections by other lake states and Canada. The federal government declined the proposal, but the sizable controversy it engendered reflects the growing sensitivity to water resources issues in the Great Lakes Basin and is also illustrative of problems to be expected from a drier future climate (as hypothesized by certain global climate models as a result of ever-increasing trace gases in the atmosphere). This case study illustrates the value of using seasonal climate predictions of limited skill, and the need for better near real-time climatic data, including information about physical impacts of current climatic conditions.

End of the Snow Drought in Illinois

With the looming winter storm expected to reach Illinois on Wednesday and Thursday, we should see the end of the 2012 snow drought in Illinois. Last winter’s snowfall season was cut short by warm and dry conditions in February and March. Meanwhile, the start of this winter’s snowfall was much delayed by the warm, dry conditions of the past several weeks. As a result, many sites in northern and central Illinois approached or set their records for the longest snow-free period.

Here is the map of total snowfall for this winter through December 17, how much we normally get through December 17, followed by reports on the remarkable snow-free season in Illinois. A few sites in western Illinois reported snowfall this morning.

dec17snow

Normal snowfall from November 1 to December 17 for the period 1981-2010.
Normal snowfall from November 1 to December 17 for the period 1981-2010.

Here is the report for Chicago. Here are additional reports for central Illinois and northwest Illinois.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
1153 AM CST MON DEC 17 2012 /1253 PM EST MON DEC 17 2012/
...LATEST ON SNOWFALL RECORDS...
SUNDAY DECEMBER 16TH MARKED THE 287TH CONSECUTIVE DAY WITHOUT
MEASURABLE SNOWFALL AT ROCKFORD...BREAKING THE PREVIOUS
CONSECUTIVE DAY RECORD THAT HAD BEEN SET IN 1922. THIS IS NOW THE
LONGEST PERIOD OF TIME WITHOUT MEASURABLE SNOWFALL IN ROCKFORD ON
RECORD. THE LAST DAY WITH MEASURABLE SNOWFALL WAS MARCH 4TH.
CHICAGO HAS ALREADY BROKEN THEIR RECORD.
ROCKFORD
RANK # DAYS DATES W/O MEASURABLE SNOW
 1) 287 03/05/2012-12/16/2012+
 2) 286 03/03/1922-12/13/1922
 3) 284 02/26/1908-12/05/1908
 4) 282 03/31/1939-01/06/1940
 5) 270 03/06/2011-11/30/2011
 270 03/10/1999-12/04/1999
CHICAGO
RANK # DAYS DATES W/O MEASURABLE SNOW
 1) 287 03/05/2012-12/16/2012+
 2) 280 03/01/1994-12/05/1994
 3) 277 03/10/1946-12/11/1946
 4) 269 03/11/1999-12/04/1999

ON AVERAGE...CHICAGO HAS 226 DAYS IN A ROW WITHOUT MEASURABLE
SNOWFALL /SEVEN AND A HALF MONTHS/ AND ROCKFORD HAS 233 /ALMOST
EIGHT MONTHS/.
GIVEN THE CURRENT FORECAST...IT APPEARS BOTH LOCATIONS COULD HAVE
THEIR RECORD SNOW DROUGHT PERIODS COME TO AN END ON WEDNESDAY NIGHT
OR THURSDAY...WITH EVEN THE POSSIBILITY OF A BRIEF SNOW EARLIER ON
TUESDAY MORNING.
HERE ARE SOME STATISTICS REGARDING FIRST/LAST MEASURABLE SNOWFALLS...
CHICAGO ROCKFORD
 EARLIEST: 10/12/2006 10/12/1909
1ST AVERAGE: NOV 16 NOV 20
 LATEST ??/??/2012 01/07/1940
EARLIEST: 02/27/1997 02/06/1911
LAST AVERAGE: APR 4 APR 1
 LATEST 05/11/1966 05/11/1966
HERE ARE THE LATEST FIRST MEASURABLE SNOWFALLS FOR CHICAGO AND
ROCKFORD...
CHICAGO ROCKFORD
1) ??/??/2012 1) 01/07/1940
2) 12/16/1965 2) 12/21/1996
3) 12/14/2001 3) 12/19/2001
4) 12/12/1946 12/19/1948
5) 12/10/2003 5) ??/??/2012
6) 12/09/2011 6) 12/14/1922
 12/09/1948 7) 12/12/1916
8) 12/07/1914 8) 12/11/1924
9) 12/06/1994 9) 12/10/1970
10) 12/05/1999 12/10/1932
 12/05/1984 11) 12/08/1956
 12/05/1973 12/08/1927
 12/05/1909 12/08/1914

$$
MTF/RODRIGUEZ

Chances of a White Christmas

What are the chances of a White Christmas (defined as at least an inch of snow on the ground on Christmas Day)? The National Climatic Data Center has updated their US map to show the current 1981-2010 averaging period. The odds are high in the Rocky Mountains, the upper Midwest, and the Northeast. However, a White Christmas is rarely, if ever, seen in much of the southern half of the US or along the West Coast.

We did a similar map with more detail for Illinois last year (second map).  It should come as no surprise that the highest odds are in northern Illinois.  In general, the odds are about 40-60 percent in the northern third of Illinois, 20-40 percent in central Illinois, and 0-20 percent in southern Illinois.

There can be large differences from site to site. Snowfall is notoriously difficult to measures with two nearby sites having different results due to exposure to sun and wind.

Chances of a White Christmas across the US. National Climatic Data Center (NOAA).
Chances of a White Christmas across the US. National Climatic Data Center (NOAA).
odds of a white Christmas
The odds of a white Christmas in Illinois, based on 1981-2010 data. Click to enlarge.

2nd Warmest January to November on Record for Illinois

The statewide average temperature in Illinois for January to November this year was 57.3 degrees, based on preliminary data. That is 3.1 degrees above normal and the second warmest on record back to 1895. Only 1921 was warmer with 57.6 degrees. This was in spite of a fall where the statewide average temperature was 52.7 degrees and 1.5 degrees below normal. Most of the above-normal warmth occurred in the January to July time frame. See graph below.

As mentioned earlier, the statewide average precipitation in Illinois for January to November this year was 27.6 inches and the 12th driest on record. This was in spite of a fall where the statewide average precipitation was 10.13 inches, 0.16 inches above normal. The graph below illustrates the beginning of a drought recovery in September and October before the dry November.

Statewide average temperature for Illinois as a departure from the 1981-2010 normal.
Statewide average temperature in Illinois for 2012 as a departure from the 1981-2010 normal.
Statewide.
Statewide average precipitation in Illinois for 2012.