North Alabama and DC Lightning Mapping

1
North Alabama and DC Lightning Mapping

• presented at the
• SPoRT Science Advisory Committee (SAC) Meeting
• 12-14 June 2007
• Richard J. Blakeslee, NASA/MSFC
• Dennis E. Buechler, UAH

2
Approach to Lightning Mapping

• New Mexico Tech Lightning Mapping Array
• Time-of-arrival system
• 10-12 stations over 50-70 km diameter area
• Passive system locates impulsive radio frequency
  signals produced by lightning (static)
• Listens in a locally unused VHF TV channel
  (e.g., Ch3, 5, 8, 10, etc.)
• Produces observations in near real-time (4-D maps
  of the lightning channel)
• Detects total lightning (i.e., CG and IC) with
  good spatial accuracy, temporal resolution, and
  high detection efficiency

3
Time-of-Arrival (TOA) Technique
Impulsive lightning event at (x, y, z, t)
Signal arrives at station i (x , y , z ) at time
t

• Measure ti at Ngt4 locations ( 50 ns accuracy)
• Solve for x, y, z, t (4 unknowns)

4
LMA Hardware

• North Alabama LMA
• LMA Sensor Sites
• VHF ground plane antenna
• Sensor electronics / site computer
• Communications (mostly 2.4 GHz wireless Ethernet
  network link)
• Relay Sites and Central Station
• PC router (up to 4 network links)
• Communications (multiple antennas require great
  care in channel selection)

5
North Alabama Lightning Mapping Array
- 10 stations over 65 x50 km diameter area -
Operational since Nov. 2001
North Alabama LMA
One hour of real-time data
6
Example of LMA Flash
7
North Alabama Observing Systems

• The LMA is a component of the Severe Thunderstorm
  Observation, Research, and Monitoring Network
  (STORMnet) providing total lightning mapping.
• STORMnet (as part of SPoRT) is a project to
  improve severe and hazardous weather forecasting
  and warning through collaboration among NASA and
  University scientists, NWS forecasters, and
  commercial partners.

ASOS
8
Total Lightning Data to the WFO
LMA AWIPS Area

• Scientific Benefits to WFOs
• Increased Situational Awareness, Confidence
  Limits
• Rapid Update- Potential for increased lead time,
  reduced FAR
• Identification of intensifying and weakening
  storms, potential severe storms, microburst wind
  shears, CG threat area
• Fills gaps in radar coverage (e.g., edge of radar
  coverage)
• Use in Warning Event Simulator for office
  training

HUN CWA
9
Flow of LMA data into AWIPS
WFO
Gridded LMA data
Forecaster at Workstation
10
NALMA Imagery in AWIPS

• Source density grids in netCDF format
• 17 height levels (0-16 km)
• Lowest level is composite
• Auto-loads 2 min grids
• 2 km horizontal grid
• 1 km vertical
• LMA image can display side-by-side with NEXRAD
  reflectivity and velocity, satellite, or other
  fields
• LMA covers 7 WFO CWAs
• Data provided to HUN, BMX, DGX, and OHX NWS
  offices

11
History of NALMA data at HUN

• November 2001 LMA operations begin
• May 2003 Started ingesting LMA data into AWIPS
• May 6, 2003 First case LMA used to warn
• August 27, 2003 First case used to not issue a
  warning
• Summer 2003 Helped install LMA data at BMX and
  OHX
• Building cases for training on WES
• Two sent to SRH WES case library
• Many more cases archived (more than 30 so far)
• Assisted other offices with software and advice

12
Alternate LISDAD II Display

• Along with AWIPS forecasters can interrogate data
  using LISDAD II software
• Provides location and number of LMA/NLDN samples
• Alternate to the AWIPS display
• Heritage Melbourne, FL (NASA, NWS, MIT/LL)

13
Washington DC Metropolitan Lightning Mapper
Demonstration

• Conceived at Southern Thunder Alliance Workshop
  (Ft Worth, TX, 2005 endorsed by SAC, 2005)
• Due to cancellation of VORTEX-II Experiment in
  2007, pursue newly available opportunity to
  deploy, evaluate, and assess the scientific and
  technological merits of total lightning mapping
  with the NMT portable LMA in an additional
  operational setting.
• Why DC Metro Area?
• Transitional climatic regime, yet still many
  severe storms
• Coverage of 3 major heavily used airports
• Complex terrain to west, urban environment
• Sterling WFO history of supporting new
  technology assessments
• Leverage with on-going TDWR evaluations
• Proximity of MDL developers to WFO forecasters
• Access to students, faculty for system
  operations/maintenance
• Local interest (broadcast community,
  researchers, forecasters)

14
Portable LMA Station(note NSSTC now building 20
portable stations)

• Electronics housed in shielded
• thermoelectric cooler enclosure
• Operate from external 12 VDC battery and/or
• power supply. 12 watts power
• Battery operation 48hours (w/out cooling)
• 20 hours (with cooling)
• Lightweight (10 lbs)

15
Washington DC LMA

• Channel 10, 192-198 MHz (upper VHF)
• 8 stations operational, 10 stations planned
  (2007)
• Data ingested into AWIPS at higher spatial and
  temporal resolution (1 km x 1 km x 1 km x 1 min)

16
DC Severe Thunderstorms 4 July 2006

• I used the DC-LMA web site to view updates on
  lightning activity during my shift at the command
  center (through about 345 PM). It was VERY
  useful, since I had no other "real-time"
  lightning data available. I used various links to
  NWS forecasts, radar, and satellite data via the
  Internet to conduct weather briefings to the
  command center staff. In addition, our WFO staff
  kept an eye on the DC area via all of the data
  available in AWIPS. the DC-LMA data were VERY
  useful in monitoring storm activity. I was able
  to show the center staff where the lightning was
  occurring. In addition, I monitored changes in
  lightning coverage/intensity as a rough gauge of
  thunderstorm changes in intensity.
• Steve Zubrick, WFO Sterling (LWX)

17
Severna Park, MD F1 Tornado28 Sept. 2006
Severna Park
DC LMA 2100-2300 UTC
DC LMA 2230-2232 UTC
18
Public Web
http//branch.nsstc.nasa.gov/PUBLIC/DCLMA

• DC LMA
• Public Web
• Site (2006)
• Model that will be used for the NALMA