A Lake Effect Snow Warning is a bulletin issued by the National Weather Service in the United States to warn of heavy snowfall amounts that are imminent from convective snow generated by very cold airmass passing over unfrozen lakes (lake effect snow). The criteria for amounts may vary significantly over different county warning areas.
Environment Canada's Meteorological Service of Canada issues similar warnings but they are called Snowsquall warnings.
Examples
URGENT - WINTER WEATHER MESSAGENATIONAL WEATHER SERVICE SALT LAKE CITY UT314 PM MST THU DEC 30 2010UTZ004-310700-/O.NEW.KSLC.LE.W.0001.101230T2214Z-101231T1700Z/SOUTHERN WASATCH FRONT-INCLUDING THE CITIES OF...LEHI...PROVO...NEPHI314 PM MST THU DEC 30 2010...LAKE EFFECT SNOW WARNING IN EFFECT UNTIL 10 AM MST FRIDAY...THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A LAKEEFFECT SNOW WARNING...WHICH IS IN EFFECT UNTIL 10 AM MST FRIDAY.* AFFECTED AREA: THE SOUTHERN WASATCH FRONT...MAINLY SOUTH OF PROVO INCLUDING THE TOWNS OF SPRINGVILLE...SPANISH FORK...PAYSON AND SANTAQUIN.* SNOW ACCUMULATIONS: AN ADDITIONAL THREE TO SIX INCHES OF SNOW...MAINLY IN THE FAVORED AREA SOUTH OF PROVO.* TIMING: LIGHT SNOW SHOWERS LATE THIS AFTERNOON WILL BECOME STRONGER LATE THIS EVENING AND TONIGHT...DIMINISHING AROUND MID MORNING FRIDAY.* IMPACTS: THE VERY COLD TEMPERATURES WILL CAUSE NUMEROUS ICY SPOTS TO DEVELOP TONIGHT. WHERE ADDITIONAL SNOW FALLS...ROADS WILL BECOME SNOW PACKED AND VISIBILITIES MAY LOCALLY BE REDUCED BELOW A HALF MILE. DANGEROUS TRAVEL CONDITIONS MAY MATERIALIZE OVERNIGHT. MOTORISTS SHOULD USE CAUTION.PRECAUTIONARY/PREPAREDNESS ACTIONS...A LAKE EFFECT SNOW WARNING MEANS SIGNIFICANT AMOUNTS OF LAKE-EFFECT SNOW ARE EXPECTED OR OCCURRING. LAKE-EFFECT SNOW SHOWERSTYPICALLY ALIGN THEMSELVES IN BANDS AND PRODUCE HEAVY SNOW WITHSUDDEN RESTRICTIONS IN VISIBILITY. DRIVING CONDITIONS MAY BEHAZARDOUS AT TIMES. USE CAUTION. KEEP AN EXTRA FLASHLIGHT...FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.FOR WINTER ROAD CONDITIONS FROM THE UTAH DEPARTMENT OFTRANSPORTATION VISIT...HTTP://WWW.COMMUTERLINK.UTAH.GOV OR DIAL511.&&$$References
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