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Florida State Univ.: "Joint regional studies, conceptual model of southern supercells, VIL and hail occurrence"

Final Report


1.1 Introduction

This report describes research completed as part of Subaward S96-71863. It also describes collaborative efforts sponsored by Subaward S94-49193 that spanned the years 1994 and 1995. Project participants at Florida State University (FSU) were Profs. Henry E. Fuelberg and Paul H. Ruscher, graduate students Eric Lenning , Doug Tunney and Darrin Lunsford (the latter two funded by the Air Force Institute of Technology), and undergraduates David Knollhoff, James Wieland, and Parks Camp. Project participants at National Weather Service (NWS)--Tallahassee (TLH) were MIC Paul Duval, SOO Andrew I. (Irv) Watson, former SOO Josh Korotky, WCM Bob Goree, DAPM Mike Vise, meteorologists David Faciane, Jeff Wallenfang, and Pat Moore, and intern Ken Gould (a former FSU graduate student). In addition, Chris Herbster received some support for his doctoral studies at FSU from the COMET project; most funding for his research came from other sources. He now is serving as a COMET post doctoral fellow at NWS TLH.

Our collaborative research consisted of three major thrusts. One objective was to examine severe local storms over the southeastern United States--both their structures and their pre-convective environments. We wanted to better understand how to discriminate between these damaging storms and their non-severe counterparts. We also investigated the detection of severe hail using Doppler radar. The second area of research was investigating the local sea breeze and determining those conditions when convection was associated with it. Finally, our third objective has examined the tropical boundary layer.

1.2 Accomplishments

Severe Storm Studies

COMET supported Mr. Eric Lenning, a graduate research assistant for Prof. Fuelberg. Mr. Lenning also was employed by NWS TLH during summer 1995 and served as a teaching assistant at COMAP ‘96 in Boulder. During the initial phase of the grant, he collaborated with WCM Bob Goree to prepare a severe storm climatology for the new TLH county warning area (CWA) using the SELS data base. This was a timely study since the warning area was greatly expanded during 1995. A paper describing these activities was presented at the 1996 Severe Local Storms Conference.

Lenning, Korotky, and Fuelberg completed a case study of the Thomasville, GA hail event of 28 January 1995. This supercell storm dropped 4 inch hail on Thomasville, causing extensive, costly damage. These were the largest hailstones ever recorded in the new TLH CWA. A paper describing this study also was presented at the 1996 Severe Local Storms Conference.

Mr. Lenning is about to complete his M.S. thesis at FSU. His thesis topic has explored the possibility of improved radar detection of hail in the Southeast. Specifically, software Build 9.0 for the WSR-88D has two algorithms which forecasters can use to identify large hail. The first provides vertically integrated liquid water content (VIL) which has been related to hail occurrence. The second is the Hail Detection Algorithm (HDA) which was introduced to replace the somewhat unsuccessful Build 8.0 hail algorithm. Both current algorithms show skill in detecting severe hail; however, each has its limitations and regional biases. Lenning’s research has developed a new method for evaluating the performance of these algorithms by incorporating census track information. He then has employed this method to determine how well each algorithm performs over the northeastern Gulf Coast region. Finally, he suggests new ways to optimize and use these algorithms to obtain the best possible hail detection. This research has included collaborations with NWS-Mobile, the National Severe Storms Laboratory, and the Operational Support Facility (OSF). The research will be completed in mid 1997 as part of the new COMET grant between FSU and NWS-TLH.

Sea Breeze Studies

The Tallahassee Area Sea Breeze Experiment (TASBEX) was conducted during summer 1994 as an experimental field program. It was supported by this project, the NWS Southern Region, and a small internal FSU grant. TASBEX exposed 25 undergraduate meteorology students to field programs and pseudo-operational forecasting for the first time. Over a three week period an intensive effort was undertaken to examine the summertime atmospheric boundary layer over the Florida panhandle. Results are summarized in a number of publications listed below. The primary findings of TASBEX were validating Ken Gould's M.S. thesis research on the sea breeze of the Florida panhandle, specifically the synoptic and mesoscale controls of sea breeze development. Fundamental atmospheric datasets (not yet fully analyzed) have been gathered for future work on the sea breeze and boundary layer structure.

NWS-TLH was a test site for the RAMSDIS hardware/software package that is used to manipulate and display GOES 8/9 imagery. NWS intern Ken Gould has used RAMSDIS to prepare a climatology of visible imagery over the Tallahassee Gulf Coast region. Fuelberg and Ruscher have assisted with this study. The goal has been to understand the local sea breeze, as evidenced by the satellite cloud patterns. Images from several warm seasons have been collected and stratified according to prevailing wind direction and time of day. Results have shown that there are preferred locations in the TLH area for sea breeze-induced convection, and that these are related to the shape of the coast line and wind direction with respect to the coast line.

COMET graduate student Douglas Tunney (USAF) completed his M.S. thesis examining the sea breeze along the Georgia Coast, with particular emphasis on the Savannah area where portions of the 1996 Olympic Games were held. Tunney, Ruscher, and Herbster were observers to the U.S. Olympic Committee/National Weather Service forecast efforts for the Olympic Games and participated in forecast seminars and supported forecast efforts for the pre-Olympic regatta in Savannah. Pat Moore, an NWS TLH meteorologist, also participated on the Olympic Forecast Team in Atlanta.

FSU undergraduate Parks Camp has been preparing a lightning climatology of the Tallahassee and Jacksonville, FL areas. He has collaborated extensively with SOO Irv Watson; Prof. Fuelberg is his FSU supervisor. This climatology is stratified according to prevailing wind direction and time of day so that it is consistent with the satellite image climatology prepared by NWS employee Ken Gould. Results for the TLH area are especially interesting because they show the effects of the complex coastline. The results are consistent with model simulations made by COMET post doctoral fellow Chris Herbster. This study will be completed in mid 1997 as part of the new COMET award between FSU and NWS-TLH.

Tropical Boundary Layer Studies

This effort, involving Mr. Darrin Lunsford and Prof. Ruscher, was initiated after several weeks of high resolution (6 second data) radiosonde data were collected for TASBEX by NWS TLH. Initial real-time assessments of these data showed that they were far more helpful in determining atmospheric boundary layer stability than are the standard mandatory/significant level data only. Thus, there was the potential for improved forecasts from Ruscher's one-dimensional column model of the atmospheric boundary layer (ABL).

With the assistance of NWS TLH and NWS Southern Region HQ, we began to acquire the data necessary for examining the tropical boundary layer in more detail. Ruscher and Lunsford now are examining 6 sec data from six rawinsonde stations during summer months. There are two primary purposes: a) document the structure of the tropical ABL, using the high-resolution soundings versus the ordinary mandatory/ significant level (TTAA/TTBB) parts of the sounding; and b) document the forecast impacts of such higher resolution, using the 1D column model. This model has shown applicability in a wide variety of forecast settings. Datasets have been procured, and work will be completed during summer 1997, under a newly-funded COMET project to Profs. Fuelberg and Ruscher.


There were numerous interactions between FSU and NWS in addition to the formal research activities described above. Some of these activities are only peripherally related to this research program. However, they could not have taken place as effectively without the good working relationship between FSU and NWS TLH that has been established through the COMET cooperative efforts.

Duval and Korotky taught a senior course at FSU entitled "NWS Operational Meteorology" during the Spring 1994 and 1995 semesters. This course is very popular with seniors and graduate students who are contemplating NWS employments. Duval taught the course in Spring 1996, and it continues with Watson and Duval during Spring 1997.
Ruscher is a member of the NW Florida 88D Unit Radar Committee (URC) at Eglin AFB through his involvement in this project.
FSU hosted the award-winning TLH NWS home page on its computers from 1994-1996.
Fuelberg was co-lead instructor for COMAP ‘96, while Lenning was the teaching assistant.
FSU feeds NWS TLH the IDD Family of Services products through the Unidata LDM, and continues with its McIDAS agreement (although that is superfluous with RAMSDIS now installed).
NWS TLH has agreed to provide FSU with a LDM feed of the meso-eta model.
NWS has provided FSU with various types of archived meteorological data, in support of this COMET project. They also have provided data to other faculty and students
Two labs on Doppler radar interpretation were developed by Ruscher and Gould for use in Ruscher's Synoptic Meteorology II course. In addition, two sea breeze development labs have been developed under this 1994 support.
NWS TLH and NWS MLB continue to provide numerous pamphlets, publications, and other information to Florida teachers involved in two FSU Meteorology K-12 educational programs, Florida EXPLORES! and the Florida Student Weather Network (FSWN)
Occasional 1800 UTC radiosonde releases have provided more convenient access for students as well as intermediate verification of PBL structure forecasted by the 1D PBL model. On several days, 1500 and 2100 UTC releases were also conducted for TASBEX.
High resolution rawinsonde data were made available in support of TASBEX . The incorporation of these data (at 6 sec intervals) into 1D PBL model forecasts of boundary layer structure provided detailed description of the temporal evolution of the SBF and PBL top.
In December of 1996, FSU resumed operation of the NOAA Dobson spectrophotometer, taking ozone observations three times per day as part of the international ozone monitoring effort. This ended a three year commitment by NWS TLH to maintain the monitoring that had begun at FSU in the 1960s. It was necessitated by the move of the NWS TLH office from the old control tower to the new terminal at the Tallahassee Regional Airport.
Fuelberg has "worked" several shifts at NWS TLH.
NWS TLH personnel participated in the FSU Career Days and have informally assisted FSU students in applying for employment with NWS.
FSU provides library privileges to NWS personnel.
Fuelberg, Korotky, and graduate students attended a meeting at NWS MLB of SOOs and other interested parties in June 1995 concerning mesoscale modeling of the Florida area.
During Spring 1995, NWS TLH sponsored an operations course at their office. The speaker was Dr. Ralph Petersen from NCEP. Fuelberg and Ruscher attended. A special guest was Vickie Johnson of COMET.


Elsner, J.B., H.E. Fuelberg, R.L. Deal III, J.A. Orrock, G.S. Lehmiller, and P.H. Ruscher, 1996: Tallahassee, Florida, minimum temperature anomaly: Description and speculations. Bull. Amer. Meteor. Soc., 77, 721-728.

Fuelberg, H.E., and D.G. Biggar, 1994: The pre-convective environment for summer thunderstorms over the Florida panhandle. Wea. and Forecasting, 9, 316-326.

Gould, K.J., and H.E. Fuelberg, 1996: The use of GOES-8 imagery and RAMSDIS to develop a sea breeze climatology over the Florida panhandle. Preprints Eighth Conf. Satellite Meteor. and Ocean, Atlanta, Amer. Meteor. Soc., 100-104.

Gould, K., P. Ruscher, and B. Hagemeyer, 1997: The interaction of the Florida east coast sea breeze front with a ring outflow boundary. Wea. Forecast., to be re-submitted.

Gould, K., P. Ruscher, and W. D. Korotky, 1997: The central Florida panhandle sea breeze and its interaction with bay breezes and convective boundaries. Wea. Forecast., to be re-submitted.

Herbster, C., P. Ruscher, and S. Chen, 1996: Modelling of the sea breeze in a region of complex coastline shape. Mon. Wea. Rev., submitted and in review.

Herbster, C. H., and P. H. Ruscher, 1996: Results from the Tallahassee Area Sea Breeze Experiment (TASBEX). Preprints, AMS Conference on Coastal Oceanic and Atmospheric Prediction, Atlanta, GA.

Herbster, C. H., and P. H. Ruscher, 1995: The Tallahassee Area Sea Breeze Experiment. Preprints, AMS Symposium on Instruments and Observations, Charlotte, NC.

Kara, A. B., J. E. Elsner, and P. H. Ruscher, 1997: Examination of minimum temperature forecasts using a one-dimensional model of the atmospheric boundary layer. Wea. Forecast., accepted and in revision.

Lenning, E.A., J. Korotky, and H.E. Fuelberg, 1996: The Thomasville, Georgia supercell hailstorm of 28 January 1995. Preprints Eighteenth Conf. Severe Local Storms, San Francisco, Amer. Meteor. Soc., 91-95.

Lenning, E.A., H.E. Fuelberg, and B. Goree, 1996: An analysis of severe weather reports for the new Tallahassee, Florida county warning area. Preprints Eighteenth Conf. Severe Local Storms, San Francisco, Amer. Meteor. Soc., 330- 334.

Lenning, E.A., 1997: Evaluation of the WSR-88D hail detection algorithm. Presentation at the USAF Gulf Coast Workshop, March 1997, Eglin AFB.

Lenning, E.A., H.E. Fuelberg, and A.I. Watson, 1996: A study of WSR-88D hail detection algorithms along the northeastern Gulf Coast. NWA National Conf., Cocoa Beach, FL, National Weather Assoc.

Ruscher, P., K. Gould, B. Hagemeyer, and J. Korotky, 1995: Doppler weather radar studies of the Florida sea breeze and associated mesoscale flow systems. Preprints, AMS Conference on Weather Analysis and Forecasting, Dallas, TX.

Tunney, D. and P. Ruscher, 1996: Model studies of the sea breeze in the Savannah, Georgia region, using a high-resolution numerical model. Preprints, AMS Conference on Coastal Oceanic and Atmospheric Prediction, Atlanta, GA.

Watson, A.I., P. Camp, and K. Gould, 1997: A satellite- and lightning-derived climatology of sea breeze-induced convection along the northeastern Gulf Coast. Presentation at the USAF Gulf Coast Workshop, March 1997, Eglin AFB.


4.1 The Florida State University Perspective

The COMET program has been very beneficial to FSU. Several faculty members have a strong interest in operational meteorology. COMET provides support for them to focus this interest on local forecasting problems. It allows them to investigate issues that turn out to be great fun! Although COMET faculty are interested in forecasting issues, they do not face the day to day challenges of preparing forecasts. They do not have as much time to devote to studying forecast issues. Interaction with NWS personnel provides this needed information. COMET also is a mechanism by which graduate and undergraduate students can interact with NWS personnel in ways that foster their educational experiences.

No problems were encountered.

4.2 The National Weather Service Perspective

The COMET program also continues to be of great benefit to the NWS. It has been the NWS’s pleasure to be a part of this cooperative effort. Graduate and undergraduate students have earned course credit working one-on-one with NWS staff on routine shifts. The NWS Tallahassee internet connection through FSU has continued to provide the critical link to the server for the immensely popular NWS Tallahassee Home Page.

As NWS Tallahassee accepts more forecasting and met-watch responsibilities as part of the NWS modernization program, less time will be devoted to research. This makes the COMET program and the affiliation with the FSU Meteorology Department even more important. Studies such as Eric Lenning’s hail investigation provide the NWS new insights and understandings of the WSR-88D hail and VIL algorithms. His novel approach incorporating census information makes his study more accurate. The NWS Tallahassee twice daily operational MM5 model runs also are an outgrowth of the close cooperation between the NWS and FSU. We would like to recognize all the cooperative efforts. Section 2 contains only a partial listing of the NWS/FSU exchanges. It is important that we continue these endeavors in the upcoming years.

The main impediment to additional cooperative activities continues to be the physical distance separating the NWS Office from the FSU Meteorology Department. This "problem" will be resolved when true collocation is accomplished, sometime early in the year 2000.