National Weather Service Wilmington, OH Seth Binau Dan Hawblitzel NOAA/NWS Wilmington OH June 23...

National Weather ServiceWilmington, OH

Seth Binau Dan Hawblitzel NOAA/NWS Wilmington OH

June 23 2010

TDWR Detection of Small-Scale Thunderstorm Events

National Weather ServiceWilmington, OH

Outline• Overview of ILN TDWR network

• Severe cases caught by TDWR, but not 88D– Height above ground level– Viewing angle– Temporal resolution

• Hints of severe weather occurring on 88D data

National Weather ServiceWilmington, OH

TDWR Overview – Locations

WDTB TDWR Training – Part One

National Weather ServiceWilmington, OH

TDWR Locations – WFO ILN• A nearly ideal setup• 3 TDWRs

– TCVG (Cincinnati)– TDAY (Dayton)– TCMH (Columbus)

• Cover nearly all of the ILN forecast area with VCP80 data– One volume scan/minute– Redundancy if 88-D fails

National Weather ServiceWilmington, OH

TDWR Locations – WFO ILN

• 90% of CWA covered by at least one TDWR• 49 of 52 counties

• 20% of CWA covered by two TDWRs

• 65% of CWA closer to TDWR than 88D

National Weather ServiceWilmington, OH

Examples To Follow

Falmouth KY Downburst

Ripley IN TornadoDarke County Straight-Line Winds

Mason KY Downburst

National Weather ServiceWilmington, OH

Ripley (IN) Tornado – Mar 8 2009

Courtesy: Charles Woodrum (PBZ)

National Weather ServiceWilmington, OH

Ripley (IN) Tornado – Mar 8 2009

Courtesy: Charles Woodrum (PBZ)

TCVG 0.1 Reflectivity Loop TCVG 0.1 SRM Loop

KILN 0.5 Reflectivity Loop KILN 0.5 SRM Loop

National Weather ServiceWilmington, OH

Ripley (IN) Tornado – Mar 8 2009

Courtesy: Charles Woodrum (PBZ)

National Weather ServiceWilmington, OH

• Evident on TDWR: Tight spin-up as convergence acts on kink in storm-scale boundary

• Evident on 88D: Boundary, convergence

Ripley (IN) Tornado – Mar 8 2009

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

TDAY 0.3 Reflectivity – 0045Z KILN 0.5 Reflectivity – 0047Z

TDAY 0.3 Velocity – 0045Z KILN 0.5 Velocity – 0047Z

~350ft AGL ~3000ft AGL

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

TDAY 0.3 Reflectivity – 0047Z KILN 0.5 Reflectivity – 0047Z

TDAY 0.3 Velocity – 0047Z KILN 0.5 Velocity – 0047Z

~350ft AGL ~3000ft AGL

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

TDAY 0.3 Reflectivity – 0049Z KILN 0.5 Reflectivity – 0051Z

TDAY 0.3 Velocity – 0049Z KILN 0.5 Velocity – 0051Z

~350ft AGL ~3000ft AGL

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

TDAY 0.3 Reflectivity – 0051Z KILN 0.5 Reflectivity – 0051Z

TDAY 0.3 Velocity – 0051Z KILN 0.5 Velocity – 0051Z

~350ft AGL ~3000ft AGL

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

TDAY 0.3 Reflectivity – 0056Z KILN 0.5 Reflectivity – 0056Z

TDAY 0.3 Velocity – 0056Z KILN 0.5 Velocity – 0056Z

~350ft AGL ~3000ft AGL

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

TDAY 0.3 Reflectivity – 0100Z KILN 0.5 Reflectivity – 0100Z

TDAY 0.3 Velocity – 0100Z KILN 0.5 Velocity – 0100Z

~350ft AGL ~3000ft AGL

National Weather ServiceWilmington, OH

Darke County (OH) – May 7 2010

TDAY 0.3 Reflectivity – 0104Z KILN 0.5 Reflectivity – 0104Z

TDAY 0.3 Velocity – 0104Z KILN 0.5 Velocity – 0104Z

~350ft AGL ~3000ft AGL

National Weather ServiceWilmington, OH

Darke County (OH) Straight-Line Winds May 7 2010

• Evident on TDWR: Intensifying RIJ; near-ground divergence; ground-relative velocity >70 kt

• Evident on 88D: deepening/strengthening MARC (weak!)

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

Classic Pulse Severe/Downburst Sounding

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2308Z

TCVG 0.1 Velocity – 2308Z

KILN 0.5 Reflectivity – 2308Z

KILN 0.5 Velocity – 2308Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2309Z KILN 0.5 Reflectivity – 2308Z

TCVG 0.1 Velocity – 2309Z KILN 0.5 Velocity – 2308Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2310Z KILN 0.5 Reflectivity – 2308Z

TCVG 0.1 Velocity – 2310Z KILN 0.5 Velocity – 2308Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2311Z KILN 0.5 Reflectivity – 2313Z

TCVG 0.1 Velocity – 2311Z KILN 0.5 Velocity – 2313Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2312Z KILN 0.5 Reflectivity – 2313Z

TCVG 0.1 Velocity – 2312Z KILN 0.5 Velocity – 2313Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2313Z KILN 0.5 Reflectivity – 2313Z

TCVG 0.1 Velocity – 2313Z KILN 0.5 Velocity – 2313Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2314Z KILN 0.5 Reflectivity – 2313Z

TCVG 0.1 Velocity – 2314Z KILN 0.5 Velocity – 2313Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

TCVG 0.1 Reflectivity – 2315Z KILN 0.5 Reflectivity – 2317Z

TCVG 0.1 Velocity – 2315Z KILN 0.5 Velocity – 2317Z

~750ft AGL ~4200ft AGL

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

• Evident on TDWR: Near-ground divergence associated with downburst; 1-min of 40-kt V

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

• Evident on 88D: Descending core aloft

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

• Evident on 88D: Descending core aloft

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

• Evident on 88D: Descending core aloft

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

• Evident on 88D: Descending core aloft

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

• Evident on 88D: Descending core aloft

National Weather ServiceWilmington, OH

May 28 2010 – Falmouth KY Downburst

• Evident on 88D: Descending core aloft

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0033Z KILN 0.5 Reflectivity – 0034Z

TCVG 0.1 Velocity – 0033Z KILN 0.5 Velocity – 0034Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0034Z KILN 0.5 Reflectivity – 0034Z

TCVG 0.1 Velocity – 0034Z KILN 0.5 Velocity – 0034Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0035Z KILN 0.5 Reflectivity – 0034Z

TCVG 0.1 Velocity – 0035Z KILN 0.5 Velocity – 0034Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0036Z KILN 0.5 Reflectivity – 0038Z

TCVG 0.1 Velocity – 0036Z KILN 0.5 Velocity – 0038Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0037Z KILN 0.5 Reflectivity – 0038Z

TCVG 0.1 Velocity – 0037Z KILN 0.5 Velocity – 0038Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0038Z KILN 0.5 Reflectivity – 0038Z

TCVG 0.1 Velocity – 0038Z KILN 0.5 Velocity – 0038Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0039Z KILN 0.5 Reflectivity – 0038Z

TCVG 0.1 Velocity – 0039Z KILN 0.5 Velocity – 0038Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

Mason County KY Downburst – June 15, 2010

TCVG 0.1 Reflectivity – 0040Z KILN 0.5 Reflectivity – 0038Z

TCVG 0.1 Velocity – 0040Z KILN 0.5 Velocity – 0038Z

~800ft AGL ~4100ft AGL

National Weather ServiceWilmington, OH

• Evident on TDWR: 60+ kt winds 800 ft AGL 24-kt winds 2400 ft AGL

at time of damage 12 min AFTER damage

Mason County KY Downburst – June 15, 2010

National Weather ServiceWilmington, OH

• Evident on 88D: 25-kt MARC at 9300 ft AGL Almost no MARC at

12 min BEFORE damage time of damage

Mason County KY Downburst – June 15, 2010

National Weather ServiceWilmington, OH

Conclusions• Low level scans of TDWR reveal much goes on

below lowest 0.5 scan of 88D• Tornado “spin ups”

– May have to rely on conceptual model – Upward tilting/stretching acting on storm-scale

boundary (landspout mechanism)• eg storm merger + “kink” in boundary

– Warn on conceptual model even if no rotation?

National Weather ServiceWilmington, OH

Conclusions• Highest winds at base of downburst may be

significantly below radar beam

• Must rely on indicators before core hits the ground

• MARC– Poor viewing angle?– Consider trends

National Weather ServiceWilmington, OH

Bottom Line: Many small-scale tornado and wind events will go undetected on 88D data

Even IF event is detected (eg TDWR), lead time will be very little if not negative

What do we do to anticipate severe winds or non-descending tornadoes?

National Weather ServiceWilmington, OH

Thanks!

Seth.Binau@noaa.govDaniel.Hawblitzel@noaa.gov