Winter Weather Meeting

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Winter Weather Meeting

• Leonard Vaughan
• NWS Meteorologist

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Winter Storm Outlook (HWO)

• Winter Storm Outlook (HWO)
• 1-7 day time period       
• 30 or greater probability of meeting local
  warning criteria
• Update if threat changes.

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Winter Weather Watch (WSW)

• Winter Weather Watch (WSW)
• Winter Storm, Blizzard, Wind Chill Watch
• 12-48 hour time period (2nd, 3rd, or occasionally
  4th periods)
• 50 or greater probability of meeting local
  warning criteria
•  

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Winter Weather Watch Criteria

• (Winter Storm)2 to 4 ( 3) inches of snow/sleet
  or ¼ in. of freezing rain 24 hrs. 
• (Blizzard)heavy snow/vsyb lt ¼ mile and wind gt
  35 mph for 3 hrs, 12-36 hour period.
• (Wind Chill)-15 degrees or colder

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Winter Weather Warning (WSW)

• Winter Weather Warning (WSW)
• Winter Storm, Heavy Snow, Ice Storm, Sleet,
  Blizzard, Wind Chill Warning
• 12-36 hour time period (1st, 2nd, or occasionally
  3rd periods)
• 80 or greater probability of meeting local
  warning criteria

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Winter Weather Warning Criteria

• (Winter Storm)2 inches snow in 12 hrs
• 2 to 4 ( 3) inches of snow/sleet in 24 hrs
• ¼ inch of freezing rain in 12-24 hrs.
• (Blizzard)heavy snow/vsyb lt ¼ mile and wind gt
  35 mph for 3 hrs within first 12 hrs.
• (Wind Chill)-15 degrees or colder

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Winter Weather Advisory (WSW)

• Winter Weather Advisory (WSW)
• Winter Weather, Snow and Blowing Snow, Snow,
  Blowing Snow, Freezing Rain, Sleet, Wind Chill
  Advisory
• 12-36 hour time period (1st, 2nd, or occasionally
  3rd periods)
• 80 or greater probability of meeting local
  warning criteria
• For freezing rain event, POP for FZRA should be
  60 or higher

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Winter Weather Advisory Criteria

• Snow/Sleet Advisory1 in. or less
• Freezing Rain Advisorylt ¼ in.
• Wind Chill Advisory0 to -14 degrees F
• Blowing Snow Advisoryheavy snow/vsby lt ¼ mile
  and wind and wind lt 35 mph for 3 hrs within first
  12 hrs.

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Criteria for Winter Weather Advisories

• Snow and/or Sleet 1/2 inch regardless of time
  period
• Can be worded as around an inch
• Freezing Rain Any accretion of freezing rain or
  freezing drizzle on roads and/or sidewalks

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Criteria for Winter Storm Warning Freezing Rain

• 1/4 inch regardless to time period

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Criteria for Winter Storm Warning Snow and/or
Sleet

• 12-hr criteria 2 inches
• Can word as 1 to 3 inches or around 2 inches
• 24-hr criteria 3 inches
• Can word as 2 to 4 inches or around 3 inches

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OutlooksLead Times

• Strive for 48 to 60 hours
• Long holiday weekends may require longer lead
  times

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WatchesLead Times

• Strive for 24 to 36 hours
• Long holiday weekends may require longer lead
  times

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Warnings and Advisories Lead Times

• Strive for 12 to 24 hours
• Longer in exceptionally high confidence
  situations
• Long holiday weekends may require longer lead
  times

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Lead Time Summary

• Warnings 12 - 24 hrs
• Watches 24 36 hrs
• Outlooks 48 - 60 hrs

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Winter Outlook
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Winter Outlook El Nino
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Effects
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• Course will run through March 3rd.
• Any questions you can e-mail Jim or Leonard at
• Jim.Kilmer_at_noaa.gov
• Leonard.Vaughan_at_noaa.gov