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watch_warning_criteria [2017/04/15 01:48]
forsythsnow 		watch_warning_criteria [2017/04/18 14:48] (current)
pcbjr
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 ====== Watch/​Warning Criteria by NWS WFO ====== ====== Watch/​Warning Criteria by NWS WFO ======
 +This is a section in where you can view the criteria for advisories, watches, and warnings issued by the [[nws_offices|NWS]] offices.
  
 ===== AKQ Wakefield ===== ===== AKQ Wakefield =====
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   * Blizzard Warning - Issued up to 36 hours before a potential blizzard with the probability of occurring at 80% or greater. A blizzard is defined as frequent wind gusts exceeding 35mph with heavy snowfall reducing visibility to less than 1/4 mile for at least 3 hours.   * Blizzard Warning - Issued up to 36 hours before a potential blizzard with the probability of occurring at 80% or greater. A blizzard is defined as frequent wind gusts exceeding 35mph with heavy snowfall reducing visibility to less than 1/4 mile for at least 3 hours.
 === Freezing Rain === === Freezing Rain ===
-  * Freezing Rain Advisory - +  * Freezing Rain Advisory - Issued within 36 hours of an ice event that has at least an 80% chance of occurring, but in which the threat does not exceed warning criteria. 
-  * Ice Storm Warning -+  * Ice Storm Warning - Issued within 36 hours of an ice event that has at least an 80% chance of occurring, in which 1/4"+ of freezing rain is possible.
 === Wind Chill === === Wind Chill ===
-  * Wind Chill Watch - Issued 12 - 48 hours before a time in which there is a 50% or greater chance the  wind chill could be -10F or below. +  * Wind Chill Watch - Issued 12 - 48 hours before a time in which there is a 50% or greater chance ​where the wind chill could be -10F or below. 
-  * Wind Chill Advisory - +  * Wind Chill Advisory - Issued within 36 hours before a time in which there is an 80% or greater chance of where the wind chil could be between 5F and -10F. 
-  * Wind Chill Warning - +  * Wind Chill Warning - Issued within 36 hours before a time in which there is an 80% or greater chance of where the wind chil could be -10F or below.
 ===== GSP Greenville Spartanburg ===== ===== GSP Greenville Spartanburg =====
 ===== HUN Huntsville ===== ===== HUN Huntsville =====
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 ===== JAN Jackson ===== ===== JAN Jackson =====
 ===== JAX Jacksonville ===== ===== JAX Jacksonville =====
 +
 +The JAX main page links here - http://​www.weather.gov/​safety/​ - Apparently JAX does not publish its own criteria.
 +
 ===== LCH Lake Charles ===== ===== LCH Lake Charles =====
 +
 ===== LIX New Orleans ===== ===== LIX New Orleans =====
 ===== LZK Little Rock ===== ===== LZK Little Rock =====
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 ===== OHX Nashville ===== ===== OHX Nashville =====
 ===== RAH Raleigh ===== ===== RAH Raleigh =====
 +==== Severe Weather ====
 +
 +**SEVERE THUNDERSTORM WARNING**
 +Thunderstorm winds 58 mph (50 kts) and/or hail 1 inch (2.5 cm) or greater
 +
 +**TORNADO WARNING**
 +A tornado has been spotted or detected on radar
 +
 +**FLASH FLOOD WARNING**
 +Short duration (usually less than six hours), flash flooding resulting from storms with rainfall rates of 1 to 2 inches per hour or greater. Also issued when a dam has failed or when a dam failure is imminent.
 +
 +**FLOOD WARNING (AREAL/​COUNTY)**
 +Long duration (slow to evolve), flooding resulting from steady stratiform rain with rates typically less than 1 inch per hour. Most common during long duration spring rains resulting in widespread flooding.
 +
 +**RIVER FLOOD WARNING**
 +River flooding is occurring or is forecast for a point. Normally issued when flooding is forecast within 24 hours based on accumulated rainfall, but may also be issued when there is a high confidence in a heavy rain event.
 +
 +**HIGH WIND WARNING**
 +Non-convective sustained wind speeds 40 mph (35 kt) and greater and/or frequent wind gusts 50 mph (43 kt) and greater or any winds gusts 57 mph (50 kt) and greater
 +
 +==== Winter Weather ====
 +
 +**WINTER STORM WARNING**
 +Snow accumulations 3 inches or greater in 12 hours (4 inches or more in 24 hours); Freezing rain accumulations ¼ inch (6 mm) or greater; Sleet accumulations ½ inch (13 mm)or more. Issued when there is at least a 60% forecast confidence of any one of the three criteria being met.
 +
 +**BLIZZARD WARNING**
 +Winds 35 mph (30 kts) AND falling and/or blowing snow reducing visibility to less than ¼ mile (1.2 km) for at least three hours
 +
 +**ICE STORM WARNING**
 +Freezing rain accumulations ¼ inch (6 mm) or greater resulting in significant,​ widespread power outages, tree damage and dangerous travel. Issued only in those rare instances where just heavy freezing rain is expected and there will be no "mixed bag" precipitation meaning no snow, sleet or rain.
 +
 +**WIND CHILL WARNING**
 +Wind chill -15ºF or lower with wind speeds 10 mph (9 kt) or greater
 +
 +**FREEZE WARNING**
 +When temperatures will be at or below 32ºF over a large area for a significant time during the growing season
 +
 +
 +
 +**EXCESSIVE HEAT WARNING**
 +Heat Index of 110ºF or greater for any duration
 +
 +**RED FLAG / FIRE WEATHER**
 +Dangerous fire behavior expected within 12-24 hours based on weather conditions and dry fuels. Generally wind gusts 20 mph (17 kt) or greater, minimum humidity 25% or lower and dry fuels. Coordinated with the NC Division of Forestry.
 +
 +==== **Advisories** ====
 +
 +**FLOOD ADVISORY** ​
 +Localized flooding resulting from heavy rain. Water may start to threaten homes and businesses, and minor flooding of roads is possible
 +
 +**WINTER WEATHER ADVISORY**
 +Snow accumulations 1-3 inches; Any freezing rain accumulations less than ¼ inch; Any sleet accumulations less than ½ inch. Winter Weather Advisories are issued in any one of the three criteria are forecast to be met
 +
 +**WIND CHILL ADVISORY**
 +0ºF to -14ºF with wind speeds 10 mph (9 kt) or greater
 +
 +**FROST ADVISORY**
 +When frost is expected during the growing season
 +
 +**WIND ADVISORY**
 +Non-convective sustained wind speeds 31-39 mph (27-34 kt); frequent wind gusts 40-45 mph (35-39 kt); any wind gusts 46-57 mph (40-50 kt)
 +
 +**HEAT ADVISORY**
 +Heat Index of 105ºF to 109ºF for 3 hours or more. Can also be issued for lower values 100ºF to 104ºF for heat lasting several consecutive days
 +
 +**DENSE FOG ADVISORY**
 +Fog reducing visibilities to a ¼ mile (0.4 km) or less
 +
 +**DENSE SMOKE ADVISORY**
 +Smoke reducing visibilities to a ¼ mile (0.4 km) or less and/or smoke expected to cause travel hazards. Could be localized or widespread
 ===== SHV Shreveport ===== ===== SHV Shreveport =====
 ===== TLH Tallahassee ===== ===== TLH Tallahassee =====