Winter Weather advisory
A Winter Weather Advisory is issued by the National Weather Service of the United States when a low pressure system produces a combination of winter weather (snow, freezing rain, or sleet) that presents a hazard, but does not meet warning criteria. A Winter Weather Advisory is similar to significant weather advisory, but a winter weather advisory is an official product. A similar warning is issued by Environment Canada's Meteorological Service of Canada offices.
The advisory criteria vary from area to area. For example, any measurable snow will constitute the advisory in Florida, while 3 to 5 inches will do so in New England. If other forms of wintry precipitation are expected, then a Winter Weather Advisory or Winter Storm Warning can be issued, also depending on the amount of precipitation that is expected.
Prior to the 2008-09 winter storm season, there was the Snow Advisory, specific for when snow was the only hazard expected in the advised area, the Sleet Advisory, specific for when sleet was the only hazard expected in the advised area, the Blowing Snow Advisory, specific for when blowing snow was the only hazard expected in the advised area, and the Snow and Blowing Snow Advisory, specific for when snow and blowing snow were the only hazards expected in the advised area. The Winter Weather Advisories for Snow, for Sleet, for Blowing Snow, and for Snow and Blowing Snow, respectively, have since replaced them.
Because of the changes with the 2008-09 winter storm season, several varieties have been noted throughout the US.
- Winter Weather Advisory for Snow (Replaced the Snow Advisory)
- Winter Weather Advisory for Snow and Blowing Snow (Replaced Blowing Snow Advisory, when conditions are not close enough to blizzard to warrant a Winter Storm Warning for Heavy Snow and Blowing Snow)
- Winter Weather Advisory for Sleet (Replaced the Sleet Advisory)
- Winter Weather Advisory for Sleet and Freezing Rain (or for Freezing Rain and Sleet) (When both the criteria for a WWA for sleet and an Freezing Rain Advisory are met) 
- Winter Weather Advisory for Freezing Rain (When the criteria for a Freezing Rain Advisory are met, and some other mentionable winter weather hazards prevent the issuance of a pure freezing rain product)
Also to be noted:
- Winter Storm Watch is given when a winter storm is likely to occur.
- Winter Storm Warning is given when a winter storm is moving into the area and that the public should take protective action.
- Also, the generic term, Winter Weather Advisory, may be used on its own, typically to indicate that all three winter precipitation types are expected in moderate amounts. However, the generic term may be used at the forecaster's discretion regardless of whether or not the condition applies
Example of a snow advisory
URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE GREAT FALLS MT 657 PM MST SUN DEC 9 2007 MTZ008>015-044-045-047-048-050>055-101100- /O.CON.KTFX.SN.Y.0025.071210T1100Z-071211T0000Z/ BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL- CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON- TOOLE-LIBERTY-BLAINE-SOUTHERN ROCKY MOUNTAIN FRONT-JUDITH BASIN- FERGUS-JEFFERSON-BROADWATER-MEAGHER-GALLATIN- INCLUDING THE CITIES OF...DILLON...BROWNING...CUT BANK...HAVRE... GREAT FALLS...FORT BENTON...HELENA...LINCOLN...ENNIS...SHELBY... CHESTER...CHINOOK...CHOTEAU...STANFORD...LEWISTOWN...BOULDER... TOWNSEND...WHITE SULPHUR SPRINGS...BOZEMAN...WEST YELLOWSTONE 657 PM MST SUN DEC 9 2007 ...SNOW ADVISORY REMAINS IN EFFECT FROM 4 AM TO 5 PM MST MONDAY FOR ELEVATIONS ABOVE 4500 FEET... A SNOW ADVISORY REMAINS IN EFFECT FROM 4 AM TO 5 PM MST MONDAY FOR ELEVATIONS ABOVE 4500 FEET. PERIODS OF LIGHT SNOW ARE EXPECTED TO FALL OVER THE ROCKY MOUNTAIN FRONT...THE CENTRAL MOUNTAINS...AND ACROSS MUCH OF SOUTHWEST MONTANA FROM MONDAY MORNING THROUGH MONDAY AFTERNOON. EXPECT NEW SNOW ACCUMULATIONS ON MONDAY TO RANGE FROM 2 TO 6 INCHES FOR ELEVATIONS ABOVE 4500 FEET...WHILE SNOW ACCUMULATIONS WILL GENERALLY BE LESS THAN 1 INCH AT LOWER ELEVATIONS. AREAS OF BLOWING AND DRIFTING SNOW WILL REDUCE VISIBILITIES AT TIMES. A SNOW ADVISORY MEANS THAT PERIODS OF SNOW WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE DRIVING. LISTEN TO NOAA WEATHER RADIO...OR YOUR LOCAL MEDIA FOR THE LATEST UPDATES ON THIS SITUATION. $$
Example of a winter weather advisory
URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE ALBUQUERQUE NM 4:12 PM MDT TUE OCT 14 2008 ...ACCUMULATING SNOW LIKELY FOR WESTERN AND NORTHERN NEW MEXICO... .A FAIRLY POTENT MID AND UPPER LEVEL LOW PRESSURE SYSTEM WILL INTENSIFY OVER ARIZONA AND HEAD SLOWLY TO THE EAST TONIGHT INTO EARLY WEDNESDAY. VERY MOIST AIR ACROSS EASTERN NEW MEXICO WILL BE LIFTED NORTH AND NORTHWESTWARD OVER A CHILLY AIRMASS THAT WILL ADVANCE TO THE SOUTH AND EAST ACROSS NEW MEXICO OVER THE NEXT 24 HOURS. THE POTENTIAL EXISTS FOR SEVERAL INCHES OF SNOW OVER THE NORTHERN AND WEST CENTRAL MOUNTAINS...THE UPPER RIO GRANDE VALLEY AND THE WESTERN REACHES OF THE NORTHEAST HIGHLANDS. NMZ003-140400- /O.NEW.KABQ.WW.Y.0016.081014T0600Z-081015T0000Z/ UPPER RIO GRANDE VALLEY- INCLUDING THE CITY OF...ESPANOLA 412 PM MDT TUE OCT 14 2008 ...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 6 PM MDT WEDNESDAY... THE NATIONAL WEATHER SERVICE IN ALBUQUERQUE HAS ISSUED A WINTER WEATHER ADVISORY FOR HEAVY SNOW...WHICH IS IN EFFECT FROM MIDNIGHT TONIGHT TO 6 PM MDT WEDNESDAY. PRECIPITATION WILL GRADUALLY INCREASE IN COVERAGE THIS EVENING AND BECOME WIDESPREAD THROUGH TUESDAY MORNING. SNOW LEVELS WILL INITIALLY BE ABOVE 8500 FEET THEN GRADUALLY FALL TO AROUND 6500 FEET BY WEDNESDAY MORNING. THE POTENTIAL EXISTS FOR 1 TO 2 INCHES ABOVE 6500 FEET...MAINLY BETWEEN EMBUDO TO NAME PUEBLO INCLUDING CHIMAYO. LESSER SNOW AMOUNTS AROUND A DUSTING ARE POSSIBLE IN THE VALLEY FLOOR. A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE DRIVING. $$ DPORTER/GUYER/CHJ