A wind chill warning is a hazardous weather statement issued by local forecast offices of the National Weather Service (NWS) in the United States and previously by the Meteorological Service of Environment and Climate Change Canada (ECCC) when wind chills are forecast to reach values low enough for residents and travelers to be susceptible to life-threatening medical conditions (such as severe frostbite and hypothermia) or death associated with accelerated body heat loss.
Extreme wind chills meeting Wind Chill Warning criteria can generate a significant decrease in body temperature, and induce frostbite damage to exposed skin and other tissue over an accelerated period of time (onsetting within as little as 10 to 15 minutes in severe cases). People within the warned area are advised to avoid venturing outdoors unless conducting necessary travel; if going outside, extra precaution should be taken against the likelihood of developing hypothermia and frostbite by wearing multiple layers of clothing (such as a thick winter coat, a scarf and long underwear, in addition to layers of outerwear) as well as a hat (e.g., a knit cap that can be used to cover the ears) and gloves.[1]
In the United States, the exact definition varies from state to state or between National Weather Service county warning areas (with the highest criteria in the Upper Midwest and Alaska, and the lowest criteria in the Florida Peninsula), and a warning is used to express more severe conditions than a wind chill advisory.[1] If extreme wind chills are expected to quickly lead to frostbite or death, then enhanced wording with the words particularly dangerous situation may be added to the text; this is rarely issued. The National Weather Service in Twin Cities/Chanhassen was the first office to do this on Sunday, January 5, 2014.[2]
As of April 8 2014, Environment Canada replaced the Wind Chill Warning with an Extreme Cold Warning. The warning is still issued based on a region's normal climate. In the older system a wind chill warning for Southern Ontario and Atlantic Canada was issued when the wind chill dropped to -35. This meant that if the temperature was with no wind a warning was not issued. Under the new system the extreme cold warning is issued based on either the temperature or the wind chill being a certain value for at least two hours. The values range from in the south to in parts of the Arctic.[3] [4]
The following is an example of a Wind Chill Warning issued by the National Weather Service office in Burlington, Vermont on February 1, 2023.[5]
983 WWUS41 KBTV 012017 WSWBTV URGENT - WINTER WEATHER MESSAGE National Weather Service Burlington VT 317 PM EST Wed Feb 1 2023 NYZ026>031-034-035-087-VTZ001>011-016>021-021000- /O.UPG.KBTV.WC.A.0001.230203T0600Z-230205T0000Z/ /O.NEW.KBTV.WC.W.0001.230203T0600Z-230204T1800Z/ Northern St. Lawrence-Northern Franklin-Eastern Clinton- Southeastern St. Lawrence-Southern Franklin-Western Clinton- Western Essex-Eastern Essex-Southwestern St. Lawrence-Grand Isle- Western Franklin-Orleans-Essex-Western Chittenden-Lamoille- Caledonia-Washington-Western Addison-Orange-Western Rutland- Eastern Franklin-Eastern Chittenden-Eastern Addison- Eastern Rutland-Western Windsor-Eastern Windsor- Including the cities of Massena, Norfolk, Fort Covington, Malone, Champlain, Plattsburgh, South Colton, Star Lake, Saranac Lake, Tupper Lake, Dannemora, Ellenburg, Lake Placid, Newcomb, Port Henry, Ticonderoga, Ogdensburg, Potsdam, Gouverneur, Alburgh, South Hero, St. Albans, Swanton, Derby, Newport, Island Pond, Lunenburg, Burlington, Shelburne, Johnson, Stowe, Hardwick, St. Johnsbury, Montpelier, Waitsfield, Middlebury, Vergennes, Bradford, Randolph, Fair Haven, Rutland, Enosburg Falls, Richford, Richmond, Underhill, Bristol, Ripton, East Wallingford, Killington, Bethel, Ludlow, Springfield, and White River Junction 317 PM EST Wed Feb 1 2023 ...WIND CHILL WARNING IN EFFECT FROM 1 AM FRIDAY TO 1 PM EST SATURDAY... * WHAT...Dangerously cold wind chills expected. Wind chills as low as 30 to 45 below zero. * WHERE...All of northern New York and Vermont. * WHEN...From 1 AM Friday to 1 PM EST Saturday. * IMPACTS...The dangerously cold wind chills could cause frostbite on exposed skin in as little as 10 minutes. * ADDITIONAL DETAILS...The lowest wind chills will occur Friday into early Saturday morning. PRECAUTIONARY/PREPAREDNESS ACTIONS... Have a plan for extreme cold conditions. Prepare your car for cold weather and ensure your home has sufficient heat. During the event, cover exposed skin and wear multiple layers of loose- fitting, light weight, and warm clothing. && $$ For more information from the National Weather Service visit http://weather.gov/btv/winter
The following is an example of a particularly dangerous situation Wind Chill Warning issued by the National Weather Service office in Chanhassen, Minnesota.[6]
WWUS43 KMPX 050957 WSWMPX URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 357 AM CST SUN JAN 5 2014 ...HISTORIC AND LIFE-THREATENING COLD AIR HAS ARRIVED... ...THIS IS A PARTICULARLY DANGEROUS SITUATION... .THE COLDEST AIRMASS SINCE 1996 CONTINUES TO MOVE SOUTHEAST OUT OF CANADA AND INTO MINNESOTA AND WISCONSIN. WIND CHILL VALUES WILL RANGE BETWEEN 30 AND 45 BELOW TODAY AND CONTINUE TO FALL THROUGH MONDAY MORNING. AIR TEMPERATURES TONIGHT WILL DROP INTO THE 20S AND 30S BELOW ZERO. GUSTY WEST OR NORTHWEST WINDS COMBINED WITH THESE EXTREMELY COLD TEMPERATURES WILL PRODUCE WIND CHILLS OF 50 TO 65 BELOW ZERO LATE TONIGHT AND EARLY MONDAY. WIND CHILLS COLDER THAN 50 BELOW CAN CAUSE EXPOSED FLESH TO FREEZE IN ONLY 5 MINUTES. A WIND CHILL WARNING IS IN EFFECT FOR CENTRAL AND SOUTHERN MINNESOTA AND WEST CENTRAL WISCONSIN THROUGH NOON TUESDAY. THE GUSTY WINDS WILL ALSO BRING AREAS OF BLOWING SNOW TO MUCH OF THE AREA TODAY AND TONIGHT. WHERE GUSTS REACH 35 TO 45 MPH OVER WESTERN AND SOUTHERN MINNESOTA...VISIBILITIES MAY OCCASIONALLY BE REDUCED TO LESS THAN A HALF MILE IN NEAR BLIZZARD CONDITIONS. THIS WILL BRING AN ADDITIONAL LEVEL OF DANGER TO ANYONE STRANDED. MNZ041-047-048-054>057-064-065-067-073>075-082>085-091>093-052115- /O.CON.KMPX.WC.W.0001.000000T0000Z-140107T1800Z/ DOUGLAS-STEVENS-POPE-LAC QUI PARLE-SWIFT-CHIPPEWA-KANDIYOHI- YELLOW MEDICINE-RENVILLE-SIBLEY-REDWOOD-BROWN-NICOLLET-WATONWAN- BLUE EARTH-WASECA-STEELE-MARTIN-FARIBAULT-FREEBORN- INCLUDING THE CITIES OF...ALEXANDRIA...MORRIS...GLENWOOD... MADISON...BENSON...MONTEVIDEO...WILLMAR...GRANITE FALLS... OLIVIA...GAYLORD...REDWOOD FALLS...NEW ULM...ST. PETER... ST. JAMES...MANKATO...WASECA...OWATONNA...FAIRMONT...BLUE EARTH... ALBERT LEA 357 AM CST SUN JAN 5 2014 ...WIND CHILL WARNING REMAINS IN EFFECT UNTIL NOON CST TUESDAY... A WIND CHILL WARNING REMAINS IN EFFECT UNTIL NOON CST TUESDAY. * THIS IS A PARTICULARLY DANGEROUS SITUATION! * WIND CHILL VALUES: 35 TO 65 BELOW...WITH THE COLDEST READINGS TONIGHT AND MONDAY MORNING. * IMPACTS: EXPOSED FLESH WILL FREEZE IN 10 MINUTES WITH WIND CHILLS OF 35 BELOW...AND IN 5 MINUTES WITH WIND CHILLS OF 50 BELOW OR COLDER. * OTHER IMPACTS...WINDS GUSTING BETWEEN 35 AND 45 MPH THIS AFTERNOON AND TONIGHT WILL LEAD TO BLOWING SNOW WITH VISIBILITIES OCCASIONALLY DROPPING TO 1/2 MILE OR LESS IN NEAR BLIZZARD CONDITIONS. SHOULD YOUR VEHICLE BECOME STRANDED...YOUR LIFE WILL BE AT RISK. CONSIDER POSTPONING ALL TRAVEL. PRECAUTIONARY/PREPAREDNESS ACTIONS... A WIND CHILL WARNING MEANS THE COMBINATION OF VERY COLD AIR AND STRONG WINDS WILL CREATE DANGEROUSLY LOW WIND CHILL VALUES. THIS WILL RESULT IN FROST BITE AND LEAD TO HYPOTHERMIA OR DEATH IF PRECAUTIONS ARE NOT TAKEN. && $$ MNZ042>045-049>053-058>063-066-068>070-076>078-WIZ014>016-023>028- 052115- /O.CON.KMPX.WC.W.0001.000000T0000Z-140107T1800Z/ TODD-MORRISON-MILLE LACS-KANABEC-STEARNS-BENTON-SHERBURNE-ISANTI- CHISAGO-MEEKER-WRIGHT-HENNEPIN-ANOKA-RAMSEY-WASHINGTON-MCLEOD- CARVER-SCOTT-DAKOTA-LE SUEUR-RICE-GOODHUE-POLK-BARRON-RUSK- ST. CROIX-PIERCE-DUNN-PEPIN-CHIPPEWA-EAU CLAIRE- INCLUDING THE CITIES OF...LONG PRAIRIE...LITTLE FALLS... PRINCETON...MORA...ST. CLOUD...FOLEY...ELK RIVER...CAMBRIDGE... CENTER CITY...LITCHFIELD...MONTICELLO...MINNEAPOLIS...BLAINE... ST. PAUL...STILLWATER...HUTCHINSON...CHASKA...SHAKOPEE... BURNSVILLE...LE SUEUR...FARIBAULT...RED WING...AMERY... BALSAM LAKE...RICE LAKE...BARRON...LADYSMITH...HUDSON... NEW RICHMOND...RIVER FALLS...PRESCOTT...MENOMONIE...BOYCEVILLE... DURAND...PEPIN...CHIPPEWA FALLS...BLOOMER...EAU CLAIRE...ALTOONA 357 AM CST SUN JAN 5 2014 ...WIND CHILL WARNING REMAINS IN EFFECT UNTIL NOON CST TUESDAY... A WIND CHILL WARNING REMAINS IN EFFECT UNTIL NOON CST TUESDAY. * THIS IS A PARTICULARLY DANGEROUS SITUATION! * WIND CHILL VALUES: 35 TO 65 BELOW...WITH THE COLDEST READINGS TONIGHT AND MONDAY MORNING. * IMPACTS: EXPOSED FLESH WILL FREEZE IN 10 MINUTES WITH WIND CHILLS OF 35 BELOW...AND IN 5 MINUTES WITH WIND CHILLS OF 50 BELOW OR COLDER. * OTHER IMPACTS...AREAS OF BLOWING SNOW ARE POSSIBLE AS WINDS GUST AS HIGH AS 35 MPH THIS AFTERNOON AND TONIGHT. PRECAUTIONARY/PREPAREDNESS ACTIONS... A WIND CHILL WARNING MEANS THE COMBINATION OF VERY COLD AIR AND STRONG WINDS WILL CREATE DANGEROUSLY LOW WIND CHILL VALUES. THIS WILL RESULT IN FROST BITE AND LEAD TO HYPOTHERMIA OR DEATH IF PRECAUTIONS ARE NOT TAKEN. && $$ BORGHOFF