New U.S. National Climate Assessment Released

CS_Net_Change_in_annual_Precip_12909_v9
Observed Precipitation Changes in the US. The colors on the map show annual total precipitation changes for 1991-2012 compared to the 1901-1960 average, and show wetter conditions in most areas. The bars on the graphs show average precipitation differences by decade for 1901-2012 (relative to the 1901-1960 average) for each region. The far right bar in each graph is for 2001-2012. (Figure source: adapted from Peterson et al. 20131). Click to enlarge.

The third U.S. National Climate Assessment was released today, including state-specific fact sheets like this one for Illinois.  I’ll post some Illinois specific comments in the near future.

The assessments are mandated by law with the intent of providing the latest report of climate change and it’s impacts on the United States.

Here are the key findings for the Midwest (the Midwest report is located here):

  • In the next few decades, longer growing seasons and rising carbon dioxide levels will increase yields of some crops, though those benefits will be progressively offset by extreme weather events. Though adaptation options can reduce some of the detrimental effects, in the long term, the combined stresses associated with climate change are expected to decrease agricultural productivity.
  • The composition of the region’s forests is expected to change as rising temperatures drive habitats for many tree species northward. The role of the region’s forests as a net absorber of carbon is at risk from disruptions to forest ecosystems, in part due to climate change.
  • Increased heat wave intensity and frequency, increased humidity, degraded air quality, and reduced water quality will increase public health risks.
  • The Midwest has a highly energy-intensive economy with per capita emissions of greenhouse gases more than 20% higher than the national average. The region also has a large and increasingly utilized potential to reduce emissions that cause climate change.
  • Extreme rainfall events and flooding have increased during the last century, and these trends are expected to continue, causing erosion, declining water quality, and negative impacts on transportation, agriculture, human health, and infrastructure.
  • Climate change will exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of certain fish species, increased invasive species and harmful blooms of algae, and declining beach health. Ice cover declines will lengthen the commercial navigation season [this winter was the exception to the rule – Jim].

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

First Half of September – Wet in Eastern and Southern Illinois

The statewide average precipitation for the first half of September was 3.77 inches, which is already above the monthly normal precipitation of 3.24 inches.
However, that precipitation was not distributed equally around the state. The figure below shows that large areas across eastern and southern Illinois received 3 to 6 inches of rain (shades of dark blue and green). Meanwhile, areas north of Interstate 80 and in western Illinois were much drier with amounts of less than 2 inches. Most of the heavy precipitation fell from the remnants of Hurricane Isaac that passed through Illinois on Labor Day weekend.
Reports from individual stations ranged from 8.08 inches for the CoCoRaHS station Bush (IL-WM-4) in southern Illinois to only 0.57 inches for the CoCoRaHS station Geneva (IL-KN-1) in northeast Illinois.

Precipitation totals for September, 2012, in Illinois through the morning of September 16. Click to enlarge.