Use of LDAR II Data at WFO Fort Worth During Spring 2005

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Use of LDAR II Data at WFO Fort Worth During
Spring 2005

• Greg Patrick
• NOAA/NWS Fort Worth TX

Southern Thunder Workshop July 25, 2005
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Overview

• WFO FWD Operations
• Background and Dataset
• Examples of LDAR II applications at WFO FWD
• Severe Weather
• Aviation
• Summary and Ideas for Future Work

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46 Counties of Responsibility for Warnings and
Forecasts
Tornado, Severe Thunderstorm, Flash Flood
Warnings Hazardous Weather Events warnings,
watches, advisories, statements Short Term and 7
Day public forecasts
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46 Counties of Responsibility for Warnings and
Forecasts
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Aviation Forecasts

• Five TAF sites
• Airport Weather Warnings for KDAL and KDFW (35
  kts or ½ Hail)
• Brief Airport Operations Personnel
• Coordinate with CWSU

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WSR - 88D sites used by WFO FWD
Dedicated KFWS, KGRK Others KDYX, KFDR KSHV,
KEWX KTLX
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NCAR Auto-Nowcaster Project

• Nic Wilson (OU SOM)
• Research Goals
• Explore applications of total lightning data
  taken from LDAR II, specifically in the area of
  nowcasting
• Research the effectiveness of Flash Extent
  Density as a representation of total lightning
  data and its applications toward identifying
  storm cells and their attributes

Initiation Likelihood Field from ANC July 13, 2005
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• LDAR II Data

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LDAR II Network and Data

• 7 sensors in DFW area
• VHF pulses used to reconstruct individual cloud
  and CG flashes in 3D
• Range approx 150 km
• Data file (netCDF) arrives at WFO Fort Worth
  every 2 min
• Nine data products available for display on AWIPS
• Flash Extent Density (FED) is concise integration
  of data

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Flash Extent Density

• Individual sources shown as red dots...
• Flashes can be visualized better if you connect
  the dots in a realistic way, converting sources
  to branches.

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Flash Extent Density

• Individual sources shown as red dots...
• Flashes can be visualized better if you connect
  the dots in a realistic way, converting sources
  to branches.
• Define Flash Extent Density as the number of
  branches/minute that pass through a grid box area

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Flash Extent Density

• Flash Extent Density is the number of lightning
  branches that pass through a specific grid box
  area during a specific time interval
• Computed after all lightning sources are grouped
  together into flashes
• FED units are Flashes km-2 min-1

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Gridded LDAR II Data in AWIPS

• Available via Volume Browser
• Flash Extent Density
• 0-20 km Source Density
• Flash Initiation Point Density
• 0-3 km Source Density
• 3-6 km Source Density
• 6-9 km Source Density
• 9-12 km Source Density
• 12-15 km Source Density
• 15-18 km Source Density

• Available via main D2D Menu
• Flash Extent Density
• 0-20 km Source Density

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AWIPS Display of LDAR II Data
Option 1 Use Volume Browser
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AWIPS Display of LDAR II Data
Option 2 Use D2D Main Menu - Obs
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Current FWD Color Scale for LDAR II Gridded
Imagery
Units - Flash Products Flashes km-2 min-1 Units
- Source Products Discharges km-2 min-1
Highest Value of FED observed 30
0-20 km Source Density values can be in this
range
Compressed the scale used for radar
imagery Customized based on values of FED
observed during spring 2005
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• AWIPS Examples
• Increase in Total Lightning Activity and Patterns
  in FED imagery highlight severe weather potential
• April 10, 2005

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FED 4 Panel 2324 UTC to 2330 UTC
FED 5 VIL 53
FED 8 VIL 53
2324Z
2326Z
FED 13 VIL 51
FED 15 VIL 51
2328Z
2330Z
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FED 2338 UTC on 10 April 2005
FED 11 VIL 44
2338Z
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FED 2340 UTC on 10 April 2005
FED 13 VIL 48
2340Z
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0.5Z 2345 UTC on 10 April 2005
85 mph Tstm Gust at 2348 UTC
2345 UTC
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• AWIPS Examples
• New updraft development on the southern flank of
  a supercell
• April 25, 2005

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FED 2114 UTC 25 April 2005
2114 UTC
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FED 2116 UTC 25 April 2005
2116 UTC
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FED 2118 UTC 25 April 2005
2118 UTC
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4 Panel Reflectivity 2112Z
0.5 deg 600 AGL
10.0 deg 10,000
19.5 deg 19,000
14.0 deg 14,000
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4 Panel Reflectivity 2117Z
0.5 deg 600 AGL
10.0 deg 10,000
19.5 deg 19,000
14.0 deg 14,000
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• AWIPS Examples
• Pulse Severe Thunderstorm over Dallas County in
  a high CAPE and weak shear environment
• July 11, 2005

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FED 2206 UTC 11 July 2005
FED 5 VIL 50
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FED 2210 UTC 11 July 2005
FED 15 VIL 54
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FED 2222 UTC 11 July 2005
FED 12 VIL 56
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FED 2230 UTC 11 July 2005
FED 15 VIL 55
G60 and ¾ in hail at 2230 UTC
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FED 2240 UTC 11 July 2005
FED 20 VIL 46
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FED 2252 UTC 11 July 2005
FED 6 VIL 41
Wind Damage near Mesquite 2250 UTC
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• AWIPS Examples
• Interesting Branching and Anvil Lightning
• April and May, 2005

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Anvil Lightning 25 April 2005
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Branching 14 May 2005
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Branching 14 May 2005
-
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Branching 14 May 2005
-
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Summary and Ideas for Future Work

• FED imagery, with a 2 minute update frequency,
  has been used as a complement to WSR-88D imagery
  to help forecasters detect important storm-scale
  clues on convective organization
• Total lightning has proven valuable in aviation
  forecasting, specifically with regard to the
  inclusion or exclusion of thunderstorms in TAFs.
  FED imagery helps forecasters visualize and
  understand the thunderstorm and CG lightning
  threat.
• A time-integrated source density product could be
  developed and used to disseminate a graphical
  lightning hazard message. This product would be
  especially useful for delineating the CG threat
  in thunderstorm anvils and stratiform regions of
  MCSs.
• Explore the application of Source Density and
  Flash Initiation Point Density products

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Acknowledgements

• Matt Sardi (ITO FWD) and Jason Burks (ITO HUN)
  accomplished the special configuration needed to
  allow LDAR II data to be displayed in AWIPS D2D
• Nick Demetriades (Vaisala Corp) is the co-author
  on the conference presentation and supplied some
  of the images used in this presentation.