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Watches, Warnings and Wind on February 11, 2009

National Weather Service Partners Workshop

June 25, 2009

Ken ReevesDirector, Forecasting Operations

AccuWeather, Inc.814-235-8751

Reeves@accuweather.com

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Brief Weather Setup• Large synoptic storm moving through the

Midwest

• Lifting warm front and aligned winds

• Strong 500mb low and cold front

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NWS Products Issued• High wind warnings out for most locations east of the

Mississippi for February 11th• Wind warnings extended to East Coast in wake of front

February 12th• 7 severe weather watches issues• Many severe weather warnings issued -- offices

averaging 10 to 30 -- most tornado warnings through mid-afternoon

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Thunderstorm and Tornado Watches

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Thunderstorm and Tornado Watches

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High Wind Watches, Warnings and Advisories

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Thunderstorm and Tornado Warnings

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The Outcome• Three tornadoes reported• 335 wind report to SPC of which 18% had

verified wind speeds reaching severe criteria• Damage continued February 12th but no wind

reports to SPC• Strongest winds in the wake of the cold front

– Wind increase upon arrival of precipitation/cold front generally 10 to 30% higher than pre-frontal synoptic winds

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Surface Data from Louisville, Kentucky

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Items For Consideration• User confusion• Tornado fatigue (watch/warn)

– Another hurricane eye wall warning problem

• Optimizing for effective delivery– Large short fuse warnings areas in a storm warning

environment

• “Severe” weather reports

http://nws.met.psu.edu/severe/2009/12Feb2009.pdf

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Watches, Warnings and Wind on February 11, 2009

National Weather Service Partners Workshop

June 25, 2009

Ken ReevesDirector, Forecasting Operations

AccuWeather, Inc.814-235-8751

Reeves@accuweather.com