1 / 17

NWS St. Louis Decision Support Workshop Watch, Warning, and Advisory Products and Criteria

NWS St. Louis Decision Support Workshop Watch, Warning, and Advisory Products and Criteria. Winter Weather. Watch: Issued 24 – 36 hours in advance when warning criteria is expected to be met Warning: Life threatening conditions Advisory: Inconvenience. Winter Weather: Warning.

fagan
Download Presentation

NWS St. Louis Decision Support Workshop Watch, Warning, and Advisory Products and Criteria

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NWS St. LouisDecision Support WorkshopWatch, Warning, and Advisory Products and Criteria

  2. Winter Weather • Watch: Issued 24 – 36 hours in advance when warning criteria is expected to be met • Warning: Life threatening conditions • Advisory: Inconvenience

  3. Winter Weather: Warning • Blizzard Warning: For 3 hours or more • Sustained wind or frequent gusts of 35 mph or greater • Snow or blowing snow reducing visibility to ¼ mile or less

  4. Winter Weather: Warning • Ice Storm Warning • Ice accumulation due to freezing rain of ¼ inch or greater

  5. Winter Weather: Warning • Winter Storm Warning • 6 inches or more of snow • ½ inch or more of sleet • or a combination of winter precipitation such that the forecaster feels it will create life threatening conditions

  6. Winter Weather: Warning • Wind Chill Warning • Wind chill values -25 F or colder

  7. Winter Weather: Advisory • Freezing Rain Advisory • Ice accumulation due to freezing rain or drizzle of less than ¼ inch

  8. Winter Weather: Advisory • Winter Weather Advisory • Snow of 3 – 5 inches • Combination of winter precipitation types: light amounts • Forecaster discretion

  9. Winter Weather: Advisory • Wind Chill Advisory: • Wind chill values -15 to -24 F

  10. Severe Weather • Hazardous Weather Outlook • Quick summary of hazardous weather expected for the next 7 days • Day 1 • Day 2 - 7

  11. Severe Weather • Severe thunderstorm outlooks: Storm Prediction Center (SPC) • Day 1, Day 2, Day 3, Day 4 – 8 • Slight, Moderate, High • The probability values represent the chance of severe weather within 25 miles of any point in the area. Even a 10% chance of a tornado within 25 miles of a point means a much bigger threat than usual, and should be taken seriously.

  12. Severe Weather

  13. Severe Weather • Severe Thunderstorm/Tornado Watch • Organized episode of severe weather • Issued for 3 – 8 hours • Typically cover 25,000 square miles • Collaborated with local office

  14. Severe Weather • Tornado warning • Radar signature of circulation or spotter reports • Severe thunderstorm warning • Radar signature or spotter reports • 1 inch or larger hail • Wind gusts 50 Knots (58 mph)

  15. Flash Flood/Flood • Watch: excessive rainfall expected over the given period that may cause flooding • Flash Flood: Rapid rise of water causing inundation of normally dry areas over a period of 6 hours or less • Flood: Rise of water due to rainfall over a longer period. Flooding takes more than 6 hours to develop

  16. Excessive Heat • Watch • Excessive heat condition expected within 24 – 48 hours

  17. Excessive Heat • Advisory • Maximum Heat Index (HI) of 105 F • Maximum HI of 100 F – 104 F for 4 days • Warning • Maximum Heat Index of 110 F for 2 days • Advisory criteria met for 4 or more days • City of St. Louis: 2 days

More Related