12th Conference on Aviation Range and Aerospace Meteorology


Recent Weather Support Improvement Initiatives by the 45th Weather Squadron

William P. Roeder, 45th Weather Squadron, Patrick AFB, FL; and J. Weems and W. H. Bauman

The 45th Weather Squadron provides comprehensive weather service to America's space program at Cape Canaveral Air Force Station and NASA Kennedy Space Center. The 45th Weather Squadron (45 WS) continually strives to improve the quality of their weather support. Seven of the most recent weather support improvement initiatives will be summarized.

1. A new Lightning Launch Commit Criteria for anvil clouds was implemented in the summer of 2005. The Lightning Launch Commit Criteria are a set of 11 rules to avoid natural and rocket triggered lightning to in-flight space launch vehicles. These new Anvil Lightning Launch Commit Criteria increase launch availability under anvil clouds by an estimated 30% without compromising safety. The new rules was based on the research from the Airborne Field Mill experiment that was funded by NASA, the Titan launch program and the National Reconnaissance Office and included collaboration with NASA, USAF, NCAR, NOAA, NSSL, University of North Dakota, University of Arizona, Aerospace Corporation, and the Applied Meteorology Unit.

2. A new tool to predict the probability of lightning during the summer thunderstorm season (late May-early September) in the 45 WS lightning advisory area was implemented in April 2005. This new tool has 48% better skill than the previous tool. This new tool considers the statistically most important indexes and other parameters from the local radiosonde, the lighting flow regime across the peninsula of Florida, the 24 hour persistence, and the daily climatology of lightning frequency. This tool was developed by the Applied Meteorology Unit and integrated the results from several research projects over the past several years including M.S. theses from the Air Force Institute of Technology, Florida State University, and local studies. A graphical user interface was developed for accuracy and ease of use.

3. A new procedure to predict minimum temperatures was implemented during the winter of 2004-2005. This new procedure improved the accuracy of minimum temperature forecasts by 11F over the old tool and improved the performance of the 45 WS low temperature advisories with a 42% more meeting desired lead-time and 29% decrease (better) in false alarm rate.

4. A new climatology of downburst winds and a performance evaluation of RAOB-based downburst indexes has begun during the summer 2005. This study is being performed by Plymouth State University in NH and is funded under a NASA Space Grant.

5. A climatology of lightning probability by flow regime within 20 NM of Kennedy Space Center and within 5 NM of Patrick AFB was created by an undergraduate intern from Pennsylvania State University during the summer of 2004. This was done to supplement the new lightning probability tool previously described and was funded by Kennedy Space Center. The same student returned for an abbreviated internship during the summer of 2005 to develop other lightning climatology and is funded by Pennsylvania State University.

6. A new technique to forecast local lightning using timelines of precipitable water measured by Global Positioning Satellites is being investigated. A preliminary thesis was done at the University of Hawaii in 2000, which showed that the technique has promise. A follow-on study was done with the University of Florida during early 2005. This study verified the previous technique on independent data and developed two new operationally focused techniques for the 30-minute of desired lead-time of the 45 WS lightning advisories and the 6-8 hours of desired lead-time for major ground processing operations such as rollout of the Space Shuttle from the Vehicle Assembly Building to the launch pad. The performance of the original technique could not be duplicated. However the two new techniques showed new promise. Further development is needed before this technique is ready for operational use.

7. A new approach to forecast the end of lightning is being explored. The NASA Faculty Fellowship Program funded a visiting scientist from Oral Roberts University during the summer of 2004 to investigate the 45 WS proposed statistical forecasting of lightning cessation. A climatological distribution of times between last and second-last flashes can provide general guidance on how long to wait after a candidate last lightning flash to achieve a desired level of low probability that it was indeed the last lightning. Also, a continually-updated best fit decay curve of lightning flash rate in dying thunderstorms might be used to predict how long to wait until the probability of no more lightning reaches a desired level. This proof-of-concept study showed that the approached have good promise. Florida State University is beginning a Ph.D. dissertation in the summer of 2005 to further explore statistical forecasting of lightning.

The contributions of all the participants in these projects is gratefully acknowledged, but unfortunately the list of names is too long to be included as authors. The 45 WS is also interested in facilitating other operational research to improve weather support to America's space program. Interested researchers are encouraged to contact the 45 WS to discuss proposals.

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Poster Session 10, Range and Aerospace Posters
Wednesday, 1 February 2006, 2:30 PM-4:00 PM, Exhibit Hall A2

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