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National Weather Association 40th Conference, October 2015 This presentation discusses the early history (~1990s) of using “Total Lightning Information” in day-to-day National Weather Service (NWS) operations at NWS Melbourne FL.
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National Weather Association 40th Conference, October 2015
Early History of Using “Total Lightning Information” in National Weather Service Operations
Stephen HodanishNOAA/NWS Pueblo, CO
National Weather Association 40th Conference, October 2015
Total Lightning Information has recently become available to NWS forecasters (CG + IC + CC)
ENTLN PULSEENTLN Cloud FlashNLDN
National Weather Association 40th Conference, October 2015
This presentation discusses the early history (~1990s) of using “Total Lightning Information” in day-to-day National Weather Service (NWS) operations at NWS Melbourne FL.
National Weather Association 40th Conference, October 2015
Starting in 1989, NWS Melbourne had access to real-time CG data. • LPATS (Lightning Positioning and Tracking System),
courtesy of Atmospheric Research Systems Incorporated (ARSI). – Time of Arrival based lightning detection system.– PC based.
• Permitted forecasters to observe CG lightning locations across the Florida peninsula and
coastal waters...
CG Detection System
National Weather Association 40th Conference, October 2015
Starting in 1989, NWS Melbourne had access to real-time CG data. • LPATS (Lightning Positioning and Tracking System),
courtesy of Atmospheric Research Systems Incorporated (ARSI). – Time of Arrival based lightning detection system.– PC based.
• Permitted forecasters to observe CG lightning locations across the Florida peninsula and
coastal waters...• 10 Years prior to most other WFO’s
CG Detection System
PC based CG system at NWS MLB. Circa 1992
National Weather Association 40th Conference, October 2015
In 1993, a more robust lightning detection system became available to NWS MLB forecasters.• Lighting Detection and Ranging - LDAR• LDAR used to give increased lead time to overall
lightning activity for lightning sensitive operations in the vicinity of the Kennedy Space Center.
• Very accurate in and around KSC, but could detect lighting as far away as the extreme eastern Gulf of Mexico.
• Displays “discharge points sources” in 3D space (x,y,z).– Detects each “step” in the step-leader process.
• Detected all types of lightning (CG, IC, CC).• Data displayed real-time to forecasters at KSC and NWS
MLB.
NASA LDAR System
National Weather Association 40th Conference, October 2015
• A dedicated T1 line delivered the LDAR data to the WFO.
NASA LDAR System
LDAR display at NWS MLB. Circa 1996
National Weather Association 40th Conference, October 2015
• Example of “point sources” associated with a single flash:
NASA LDAR System
National Weather Association 40th Conference, October 2015
In 1996, in a truly landmark event, the data streams of the CG lightning data (known as NLDN by this time), KSC LDAR point source data and KMLB radar data were merged.• This system, known as the Lightning Imaging Sensor
Data Applications Display (LISDAD) was designed to do 2 things:– 1.) Compare ground-based total lightning data
(LDAR) to a satellite-based lightning detection system (Lightning Imaging Sensor).
– 2.) Observe how total lightning relates to severe convective storm morphology over the central Florida peninsula.
LISDAD
National Weather Association 40th Conference, October 2015
The LISDAD system was a collaborative agreement between NASA (Dr. Steve Goodman), the Massachusetts Institute of Technology (MIT; Dr. Earle Williams) and NWS Melbourne.
LISDAD
National Weather Association 40th Conference, October 2015
3 Lightning Systems in NWS MLB Ops area, circa ~1997
National Weather Association 40th Conference, October 2015
• First...Lightning “flashes” had to be created from the LDAR point source data. This was done using the MIT Lincoln Lab “Fixed D” flash algorithm: All LDAR point sources which occurred within 5000 m and 300 ms were defined as a “flash”.
• Storm cells were identified using the NSSL SCIT algorithm, and the lightning flashes were then linked to each storm cell using a flash association algorithm.
• Total lightning information was updated every 60 seconds while the 88D data was updated every 5 minutes (“VCP-11”).
LISDAD – How it worked
National Weather Association 40th Conference, October 2015
• Storm cells were then numbered and color coded on the LISDAD display. Forecasters had to simply click on the cell IDs, ...
LISDAD – How it worked
LISDAD display at NWS MLB. Circa 1997
National Weather Association 40th Conference, October 2015
• Storm cells were then numbered and color coded on the LISDAD display. Forecasters had to simply click on the cell IDs, and a “pop-up” box displaying a variety of lightning data and radar data for that cell would display.
LISDAD – How it worked
LISDAD display at NWS MLB. Circa 1997
National Weather Association 40th Conference, October 2015
• NWS Melbourne forecasters soon recognized warm season storms which produced rapid increases in Total Lightning activity (or “Lightning Jumps”) were conducive to severe weather activity...
LISDAD – Warm Season Pulse Severe Storms
National Weather Association 40th Conference, October 2015
• NWS Melbourne forecasters soon recognized warm season storms which produced rapid increases in Total Lightning activity (or “Lightning Jumps”) were conducive to severe weather activity…
LISDAD – Warm Season Pulse Severe Storms
National Weather Association 40th Conference, October 2015
• NWS Melbourne forecasters soon recognized warm season storms which produced rapid increases in Total Lightning activity (or “Lightning Jumps”) were conducive to severe weather activity…
LISDAD – Warm Season Pulse Severe Storms
The first “lightning jump” definition was “an increase in total lighting over a time period of at least 2 minutes, in which the total flash rate increase at least 50 flashes during the entire lightning jump time period” (AMS SLS 1998).
National Weather Association 40th Conference, October 2015
• An analysis of 18 warm season pulse severe storms in 1997 showed that a large majority (14/18) showed this “Lightning Jump” characteristic. The jump occurred about 25 minutes prior to reported severe weather.
LISDAD – Warm Season Pulse Severe Storms
National Weather Association 40th Conference, October 2015
• LISDAD captured several cool season supercells that occurred over the Florida peninsula.– Supercells typically had very high flash rates…
LISDAD – Tornadic Supercells
National Weather Association 40th Conference, October 2015
LISDAD – Tornadic Supercells
x xX = TornadoX = HailTotal lightning
flash rate of supercell storm which occurred Oct 31 1997 .
Total lightning flash rate of supercell storm which occurred Feb 23 1997.
Total lightning flash rate of supercell storm which occurred Feb 23 1998.
xX = Wind
F3 F1
National Weather Association 40th Conference, October 2015
LISDAD – Tropical Cyclone Rainband Tornadoes
• These mini-supercells did not show much lightning activity…but the lightning data did imply stronger updrafts in the strongly sheared environment
National Weather Association 40th Conference, October 2015
Shifting Gears To “Day To Day” Operational Public Products...
National Weather Association 40th Conference, October 2015
Total Lightning in Public Forecast Products: AVIATION
• Alert areas were configured with LISDAD and LDAR for NWS MLB TAF sites:– Intent was to optimize TSRA and VCTS in and around
TAF sites during the first 2 hours of the TAF
National Weather Association 40th Conference, October 2015
Total Lightning in Public Forecast Products: HWO
• HWO product was used to forecast the geographical distribution and timing of expected lightning activity (collision of sea-breezes), especially in sensitive areas where large numbers of people were gathered (tourist attractions, beaches, major golf courses, marine events)
National Weather Association 40th Conference, October 2015
Total Lightning in Public Forecast Products: Short Term Forecast “NOW” Product
• With real time lightning information and radar data (imminent outflow/sea-freeze collisions), NOW-cast were written to discuss short term lightning threat:
• “LIGHTNING STORMS WILL BE SCATTERED FROM LAKE GEORGE AND LAKE HELEN...TO LISBON...TO APOPKA AND THE CENTRAL FLORIDA ATTRACTIONS AREA. THEY WILL MOVE SLOWLY AND STRENGTHEN AS THEY COLLIDE WITH THE EAST COAST SEA BREEZE. STORMS PRODUCING EXCESSIVE LIGHTNING WILL BE POSSIBLE FROM KISSIMMEE/ST CLOUD...TO ORLANDO AND SANFORD...NORTHWARD INTO VOLUSIA COUNTY FROM DELAND TO THE COAST FROM DAYTONA BEACH NORTHWARD.”
National Weather Association 40th Conference, October 2015
Total Lightning in Public Forecast Products: SVR/SVS
• Specific CG lightning amounts were mentioned in Severe Weather Statements:
• “AT 529 PM DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 5 MILES EAST OF THE DISNEY COMPLEX.THIS STORM WILL BE CAPABLE OF PRODUCING DAMAGING WINDS…LARGE HAIL AND RAINFALL ACCUMULATIONS IN EXCESS OF 2 INCHES PER HOUR. IN ADDITION…LIGHTING DETECTION EQUIPMENT WAS INDICATING EXCESSIVE FLASH RATES OF 20 FLASHES PER MINUTE. OTHER STRONG STORMS…”
National Weather Association 40th Conference, October 2015
Boldi, R., Hodanish, S. J., Sharp, D., Williams, E., Goodman, S., Raghavan, R., Matlin, A., and M. Weber, 1998: The design and evaluation of the lightning imaging sensor data applications display (LISDAD). 19th Conf. On Severe Local Storms, Bloomington, MN, Amer. Meteor. Soc.
Hodanish, S. J., Williams E., and B. Boldi, 2013: Early history of using total lightning data at NWS Melbourne, Florida. Electronic Journal of Severe Storms Meteorology. 8(6), 1-26
Hodanish, S. J., D. Sharp, E. Williams, R. Boldi, S. Goodman, R. Raghavan, A. Matlin, and M. Weber, 1998: Comparisons between total lighting data, mesocyclone strength, and storm damage associated with the Florida tornado outbreak of February 23 1998. 19th Conf. On Severe Local Storms, Bloomington, MN, Amer. Meteor. Soc.
Hodanish, S. J. ., D. Sharp, E. Williams, R. Boldi, S. Goodman, R. Raghavan, A. Matlin, and M. Weber, 1998: Observations of total lightning associated with severe convection during the wet season in central Florida. 19th Conf. On Severe Local Storms, Bloomington, MN, Amer. Meteor. Soc.
Hodanish, S. J., 1996: Integration of lightning detection systems in a modernized national weather service office. Preprints 18th Conf. on Severe Local Storms. San Francisco, Ca., Amer. Meteor. Soc., Boston Ma
Williams, E, Boldi, B., Matlin, M., Weber, M., Hodanish, S.J., Sharp, D., Goodman, S., Raghavan, R., and D. Buechler. 1999: The behavior of total lightning activity in severe Florida thunderstorms. Atmospheric Research, 51, 245-265.
National Weather Association 40th Conference, October 2015
Summary
• This presentation reviewed the early history (1990s) of using Total Lightning Information (TLI) at NWS Melbourne Florida.
• For the first time, NWS forecasters were able to observe TLI in real-time with all types of convection.
• TLI was found to be quite useful in Severe Storm Discernment, especially warm season pulse storms (“Lightning Jumps”).
• Supercell storms in the cool season were found to have very large total flash rates.
National Weather Association 40th Conference, October 2015
Summary
• Tornadic min-supercells associated within rain-bands of tropical cyclones did not produce much total lightning, however, even the presence of infrequent lightning activity was found to be an important indicator, by serving as a proxy for enhanced updrafts, and potential for tornado-genesis.
• When storms were not severe, the word “Lightning Storm(s) were used in NWS public products.
• The amount of CG lightning was defined operationally. Excessive (CG) Lightning was defined as storm producing more than 12 flashes per minute, and was used in public products (especially NOWcasts)
• Having TLI helped considerably in aviation forecasting.
National Weather Association 40th Conference, October 2015
The End
Questions?
A special thanks goes out to many folks who made the “NWS Melbourne years” a special time…including Dave Sharp, Scott Spratt, Dr. Steve Goodman, Dr. Bob Boldi and especially Dr. Earle Williams.
