national weather service wilmington, oh seth binau dan hawblitzel noaa/nws wilmington oh june 23...
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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?