A wind chill watch is issued by the National Weather Service of the United States when the wind chill could reach dangerous levels within the next 12 to 48 hours. The exact definition required to issue a watch varies from state to state or from National Weather Service county warning areas to another, but if forecasters believe conditions are favorable for life-threatening wind chills meeting local criteria, a watch will be issued. People going outside should plan to protect themselves against hypothermia and frostbite.[1]
The following is an example of a wind chill watch issued by the National Weather Service office in Detroit, Michigan.[2]
017 WWUS43 KDTX 141646 WSWDTX URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1146 AM EST WED JAN 14 2009 ...LONG DURATION ARCTIC VISIT... .AN ARCTIC AIRMASS WILL BECOME FIRMLY ESTABLISHED OVER THE GREAT LAKES REGION TONIGHT AND WILL PERSIST THROUGH FRIDAY INTO EARLY SATURDAY. THE COMBINATION OF BITTERLY COLD AIR...WITH TEMPERATURES WELL BELOW ZERO AT TIMES...AND A PERSISTENT WIND WILL CREATE DANGEROUSLY LOW WIND CHILL VALUES. WIND CHILL READINGS WILL DIP TO AROUND -20 TONIGHT AND THURSDAY. THE HEART OF THE ARCTIC AIRMASS WILL SETTLE ACROSS THE REGION BEGINNING LATE THURSDAY AND CONTINUING INTO EARLY SATURDAY. THE ADDITION OF A PERSISTENT WIND DURING THAT TIME WILL PROPEL WIND CHILL VALUES BELOW -25 DEGREES. MIZ047>049-053>055-060>063-068>070-075-076-082-083-150100- /O.NEW.KDTX.WC.Y.0001.090115T0300Z-090116T0000Z/ /O.NEW.KDTX.WC.A.0001.090116T0000Z-090117T1500Z/ MIDLAND-BAY-HURON-SAGINAW-TUSCOLA-SANILAC-SHIAWASSEE-GENESEE- LAPEER-ST. CLAIR-LIVINGSTON-OAKLAND-MACOMB-WASHTENAW-WAYNE- LENAWEE-MONROE- INCLUDING THE CITIES OF...MIDLAND...BAY CITY...BAD AXE... SAGINAW...CARO...SANDUSKY...OWOSSO...FLINT...LAPEER... PORT HURON...HOWELL...PONTIAC...WARREN...ANN ARBOR...DETROIT... ADRIAN...MONROE 1146 AM EST WED JAN 14 2009 ...WIND CHILL ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO 7 PM EST THURSDAY... ...WIND CHILL WATCH IN EFFECT FROM THURSDAY EVENING THROUGH SATURDAY MORNING... THE NATIONAL WEATHER SERVICE IN DETROIT/PONTIAC HAS ISSUED A WIND CHILL ADVISORY...WHICH IS IN EFFECT FROM 10 PM THIS EVENING TO 7 PM EST THURSDAY. A WIND CHILL WATCH HAS ALSO BEEN ISSUED. THIS WIND CHILL WATCH IS IN EFFECT FROM THURSDAY EVENING THROUGH SATURDAY MORNING. THE COMBINATION OF BITTERLY COLD AIR AND A PERSISTENT WIND WILL CREATE DANGEROUSLY LOW WIND CHILL VALUES. WIND CHILL READINGS WILL DIP TO AROUND -20 TONIGHT AND THURSDAY. THE HEART OF THE ARCTIC AIRMASS WILL SETTLE ACROSS THE REGION BEGINNING LATE THURSDAY AND CONTINUING INTO EARLY SATURDAY. THE ADDITION OF A PERSISTENT WIND DURING THAT TIME WILL PROPEL WIND CHILL VALUES BELOW -25 DEGREES. A WIND CHILL ADVISORY MEANS THAT VERY COLD AIR AND STRONG WINDS WILL COMBINE TO GENERATE LOW WIND CHILLS. THIS WILL RESULT IN FROST BITE AND LEAD TO HYPOTHERMIA IF PRECAUTIONS ARE NOT TAKEN. IF YOU MUST VENTURE OUTDOORS...MAKE SURE YOU WEAR A HAT AND GLOVES. A WIND CHILL WATCH MEANS THERE IS THE POTENTIAL FOR A COMBINATION OF VERY COLD AIR AND STRONG WINDS TO CREATE DANGEROUSLY LOW WIND CHILL VALUES. MONITOR THE LATEST FORECASTS AND WARNINGS FOR UPDATES ON THIS SITUATION. $$ MANN