Public Information Statement
Issued by NWS Chicago, IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
000
NOUS43 KLOT 280204
PNSLOT
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
281415-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
904 PM CDT THU AUG 27 2015

...MOST TORNADOES ON RECORD IN NWS CHICAGO FORECAST AREA IN 2015...

THE FOUR TORNADOES ON AUGUST 18 2015 BROUGHT THE TOTAL NUMBER OF
CONFIRMED TORNADOES IN THE COUNTIES OF THE NWS CHICAGO COUNTY
WARNING AREA (CWA) IN 2015 UP TO 29. THIS BROKE THE PREVIOUS RECORD
OF MOST TORNADOES IN THE NWS CHICAGO CWA COUNTIES IN A YEAR SET
IN 2004...WHICH HAD 27 TORNADOES. THE PERIOD OF RECORD IS
1950-2015.

NOTE THAT IT IS LIKELY THAT MANY OF THE EARLIER YEARS IN THE
DATASET HAD WEAK (F0-F1) TORNADOES THAT WENT UNDETECTED. THE
MODERN NETWORK OF SPOTTERS AND IMPROVED RADAR TECHNOLOGY HAS
ALLOWED FOR BETTER DETECTION OF WEAK TORNADOES. THIS INCLUDES
THE INTRODUCTION OF CURRENT DOPPLER RADAR TECHNOLOGY TO THE NWS
IN 1992 AND DUAL POLARIZATION IN 2012. WITH THAT BEING SAID...
2015 HAS BEEN AN EXCEPTIONALLY ACTIVE YEAR FOR TORNADOES IN THE
NWS CHICAGO FORECAST AREA.

TOP 10 MOST TORNADOES IN NWS CHICAGO CWA COUNTIES IN A CALENDAR YEAR
--------------------------------------------------------------------

RANK  YEAR  NUMBER OF TORNADOES
----  ----  -------------------
 1    2015          29
 2    2004          27
 3    1974          22
      2010          22
 4    1965          21
 5    2003          18
      2008          18
      2011          18
      2014          18* ALL TORNADOES OCCURRED ON 6/30
 10   1967          17
      1972          17
      2013          17

THE AVERAGE NUMBER OF TORNADOES PER YEAR IN THE COUNTIES OF THE
NWS CHICAGO CWA FROM 1950-2015 IS 9 (8.98).

THE CURRENT LOCATION OF NWS CHICAGO AND THE KLOT WSR-88D DOPPLER
RADAR OPENED IN 1992. THIS IS ALSO WHEN THE CURRENT ALIGNMENT OF
COUNTIES IN THE CWA DATES BACK TO. THE AVERAGE NUMBER OF
TORNADOES IN THE NWS CHICAGO CWA FROM 1992-2015 IS 11 (10.8).

NWS CHICAGO CWA COUNTIES
------------------------
IL: BOONE, COOK, DE KALB, DUPAGE, FORD, GRUNDY, IROQUOIS, KANE,
    KANKAKEE, KENDALL, LAKE, LA SALLE, LEE, LIVINGSTON, MCHENRY,
    OGLE, WILL, WINNEBAGO

IN: BENTON, JASPER, LAKE, NEWTON, PORTER

$$

RC/MTF/BMD



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.