Publications
Medium Intensity Airport Weather System (MIAWS)
September 11, 2000
Conference Paper
Published in:
Ninth Conf. on Aviation, Range, and Aerospace Meteorology, 11-15 September 2000, pp. 122-126.
Summary
Operational experience with the Integrated Terminal Weather Systems (ITWS) and Airport Surveillance Radar, Model 9, (ASR-9) Weather System Processor (WSP) demonstration systems, studies of pilot weather avoidance decision making), and recent accidents have demonstrated the need to provide timely, accurate information on the location and movement of storms to air traffic controllers, pilots, and airline dispatch. At medium-intensity airports, generally those with too few flight operations to justify the presence of Doppler radar systems like the Terminal Doppler Weather Radar (TDWR) or the WSP, terminal air traffic surveillance is currently provided with the ASR-7 and ASR-8 radar systems. The ASR-7 and ASR-8 do not provide calibrated precipitation intensity products or any storm motion information. The Medium-Intensity Airport Weather System (MIAWS) program is intended to address these terminal weather information deficiencies. MIAWS-generated products would be displayed to tower and Terminal Radar Approach Control (TRACON) supervisors and delivered to aircraft cockpits and airline dispatchers to assist pilots during landings. Initially, the MIAWS will provide a real time display of storm positions and motion based on Next Generation Weather Radar (NEXRAD) product data using a product generation and display system derived from the WSP. Airport wind and wind shear information will be acquired from an FAA Low Level Wind Shear Alert System (LLWAS). A demonstration system will be installed and demonstrated at experimental sites in Memphis, TN and Jackson, MS in 2000 and potentially at a third site in 2001. This demonstration system will be used to assess technical and operational issues such as compensation for the relatively slow updates of the NEXRAD products and, Anomalous Propagation (AP) ground clutter. The ASR-11 is a replacement for the ASR-7/8 radars that feature a weather reflectivity processing channel. When it becomes available at MIAWS locations, the MIAWS processor will acquire and display precipitation and storm movement products derived from the ASR-11. Likewise, when an LLWAS Relocation/Sustainment (LLWAS-RS) (Nilsen, et al., 1999) becomes available at MIAWS locations, the MIAWS will acquire wind and wind shear information derived from the LLWAS-RS.
Summary
Operational experience with the Integrated Terminal Weather Systems (ITWS) and Airport Surveillance Radar, Model 9, (ASR-9) Weather System Processor (WSP) demonstration systems, studies of pilot weather avoidance decision making), and recent accidents have demonstrated the need to provide timely, accurate information on the location and movement of storms to air...
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The behavior of total lightning activity in severe Florida thunderstorms
July 1, 1999
Journal Article
Published in:
Atmos. Res., Vol. 51, Nos. 3-4, July 1999, pp. 245-265.
Summary
The development of a new observational system called LISDAD (Lightning Imaging Sensor Demonstration and Display) has enabled a study of severe weather in central Florida. The total flash rates for storms verified to be severe are found to exceed 60 fpm, with some values reaching 500 fpm. Similar to earlier results for thunderstorm microbursts, the peak flash rate preceeds the severe weather at the ground by 5-20 min. A distinguishing feature of severe storms is the presence of lightning 'jumps' -- abrupt increases in flash rate in advance of the maximum rate for the storm. The systematic total lightning precursor to severe weather of all kinds -- wind, hail, tornadoes -- is interpreted in terms of the updraft that sows the seeds aloft for severe weather at the surface and simultaneously stimulates the ice microphysics that drives the intracloud lightning activity.
Summary
The development of a new observational system called LISDAD (Lightning Imaging Sensor Demonstration and Display) has enabled a study of severe weather in central Florida. The total flash rates for storms verified to be severe are found to exceed 60 fpm, with some values reaching 500 fpm. Similar to earlier...
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Total lightning activity associated with tornadic storms
June 7, 1999
Conference Paper
Published in:
11th Int. Conf. on Atmos. Electr., 7-11 June 1999, pp. 515-518.
Summary
Severe storms often have high flash rates (in excess of one flash per second) and are dominated by intracloud lightning activity. In addition to the extraordinary flash rates, there is a second distinguishing lightning characteristic of severe storms that seems to be important. When the total lightning history is examined, one finds sudden increases in the lightning rate, which we refer to as lightning "jumps", that precede the occurrence of severe weather by ten or more minutes. These jumps are typically 30-60 flashes/min, and are easily identified as anomalously large derivatives in the flash rate. This relationship is associated with updraft intensification and updraft strength is an important factor in storm severity (through the accumulation of condensate aloft and the stretching of vorticity). In several cases, evidence for diminishment of midlevel rotation and the descent of angular momentum from aloft is present prior to the appearance of the surface tornado. Based on our experience with severe and tornadic storms in Central Florida, we believe the total lightning may augment the more traditional use of NEXRAD radars and storm spotters. However, a more rigorous relation of these jumps to storm kinematics is needed if we are to apply total lightning in a decision tree that leads to improved warning lead times and decreased false alarm rates.
Summary
Severe storms often have high flash rates (in excess of one flash per second) and are dominated by intracloud lightning activity. In addition to the extraordinary flash rates, there is a second distinguishing lightning characteristic of severe storms that seems to be important. When the total lightning history is examined...
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Comparisons between total lightning data, mesocyclone strength, and storm damage associated with the Florida tornado outbreak of February 23 1998
September 14, 1998
Conference Paper
Published in:
19th Conf. on Severe Local Storms, 14-18 September 1998, pp. 681-684.
Summary
During the late evening and early morning hours of February 22/23 1998, the worst tornado outbreak in recorded history occurred over the peninsula of central Florida. Analysis of KMLB Doppler radar data indicated at least 9 supercells developed over the region, with 4 of the supercells producing tornadoes. These 4 tornadic supercells produced a total of 7 tornadoes, some of them on the ground for tens of miles (Fig. 1.). A total of 42 fatalities were reported with over 260 injured. Monetary losses totaled over 100 million dollars. During this severe weather outbreak, National Weather Service Melbourne, in collaboration with the National Aeronautics and Space Administration and the Massachusetts Institute of Technology, was collecting data from a unique lightning observing system called Lightning Imaging Sensor Data Applications Display (LISDAD). This system has the capability to combine radar reflectivity data collected from the KMLB WSR-88D, cloud to ground data collected from the National Lightning Detection Network, and total lightning data collected from NASA's Lightning Detection And Ranging (LDAR) system. The object of this study is to compare total lightning data collected from the LISDAD system to mesocyclone strength as observed from the KMLB WSR-88D. These data will then be compared to the times of tornadic winds.
Summary
During the late evening and early morning hours of February 22/23 1998, the worst tornado outbreak in recorded history occurred over the peninsula of central Florida. Analysis of KMLB Doppler radar data indicated at least 9 supercells developed over the region, with 4 of the supercells producing tornadoes. These 4...
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Observations of total lightning associated with severe convection during the wet season in Central Florida
September 14, 1998
Conference Paper
Published in:
19th Conf. on Severe Local Storms, 14-18 September 1998, 635-638.
Summary
This paper will discuss findings of a collaborative lightning research project between the Massachusetts Institute of Technology, the National Weather Service (NWS) office in Melbourne (MLB), Florida and the National Aeronautics and Space Administration. In August 1996, NWS MLB received a workstation which incorporates data from the KMLB WSR-88D, Cloud to Ground (CG) stroke data from the National Lightning Detection Network (NLDN), and 3D volumetric lightning data collected from the Kennedy Space Centers' Lightning Detection And Ranging (LDAR) system. The two primary objectives of this lightning workstation, called Lightning Imaging Sensor Data Applications Display (L1SDAD), are to: a.) Observe how total lightning relates to severe convective storm morphology over central Florida, and, b.) Compare ground based total lightning data (LDAR) to a satellite based lightning detection system. This presentation will focus on objective #1.
Summary
This paper will discuss findings of a collaborative lightning research project between the Massachusetts Institute of Technology, the National Weather Service (NWS) office in Melbourne (MLB), Florida and the National Aeronautics and Space Administration. In August 1996, NWS MLB received a workstation which incorporates data from the KMLB WSR-88D, Cloud...
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The design and evaluation of the Lightning Imaging Sensor Data Applications Display (LISDAD)
September 14, 1998
Conference Paper
Published in:
19th Conf. on Severe Local Storms, 14-18 September 1998, pp. 631-634.
Summary
The ultimate goal of the LISDAD system is to quantify the utility of total lightning infomation in short-term, severe-weather-forecasting operations. Secondary goals were to collect times series of various storm-cell parameters that relate to storm development and electrification and subsequently make these data available for post-facto analysis. To these ends scientists from NASA, NWS, and MIT/LL organized an effort to study the relationship of lightning and severe-weather on a storm-by-storm, and even cell-by-cell basis for as many storms as possible near Melbourne, Florida. Melbourne was chosen as it offers a unique combination of high probability of severe weather and proximity to major relevant sensors, specifically: NASA's total lightning mapping system at Kennedy Space Center (the LDAR system) at KSC [Lennon and Maier, 1991], a NWS / NEXRAD radar at Melbourne, and a prototype Integrated Terminal Weather System (ITWS), at Orlando. The ITWS system obtains cloud-to-ground lightning information from the National Lightning Detection Network (NLDN) via a link to Lexington, MA, and also uses NSSL's Severe Storms Analysis Package (NSSL / SSAP) to obtain information about various storm-cell parameters
Summary
The ultimate goal of the LISDAD system is to quantify the utility of total lightning infomation in short-term, severe-weather-forecasting operations. Secondary goals were to collect times series of various storm-cell parameters that relate to storm development and electrification and subsequently make these data available for post-facto analysis. To these ends...
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Automated storm tracking for terminal air traffic control
September 1, 1995
Journal Article
Published in:
Lincoln Laboratory Journal, Vol. 7, No. 2, Fall 1994, pp. 427-448.
Topic:
R&D area:
Summary
Good estimates of storm motion are essential to improved air traffic control operations during times of inclement weather. Automating such a service is a challenge, however, because meteorological phenomena exist as complex distributed systems that exhibit motion across a wide spectrum of scales. Even when viewed from a fixed perspective, these evolving dynamic systems can test the extent of our definition of motion, as well as any attempt at automated tracking of this motion. Image-based motion detection and processing appear to provide the best route toward robust performance of an automated tracking system.
Summary
Good estimates of storm motion are essential to improved air traffic control operations during times of inclement weather. Automating such a service is a challenge, however, because meteorological phenomena exist as complex distributed systems that exhibit motion across a wide spectrum of scales. Even when viewed from a fixed perspective...
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Extrapolating storm location using the Integrated Terminal Weather System (ITWS) storm motion algorithm
March 29, 1994
Project Report
Published in:
MIT Lincoln Laboratory Report ATC-208
Summary
Storm Motion (SM) is a planned Initial Operational Capability (IOC) algorithm of the FAA's Integrated Terminal Weather System (ITWS). As currently designed, this algorithm will track the movement of storms/cells and convey this tracking information to the ITWS user by means of a graphic display of vectors (for direction) with accompanying numeric reports of storm speed, rounded to the nearest 5 nmi/hr increment. Recognizing that there are occasions when ITWS users could benefit from a more extended product format, Storm Extrapolated Position (SEP) was conceived to supplement the SM product and thereby increase the latter's accessibility as a planning aid. This communication describes a prototype SEP design along with an analysis of its accuracy and observed performance during 1993 ITWS demnstrations in Orlando (FL) and Dallas (TX).
Summary
Storm Motion (SM) is a planned Initial Operational Capability (IOC) algorithm of the FAA's Integrated Terminal Weather System (ITWS). As currently designed, this algorithm will track the movement of storms/cells and convey this tracking information to the ITWS user by means of a graphic display of vectors (for direction) with...
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