winter 1998 nssl briefings volume 2 no. 2 winter...

Winter 1998 NSSL Briefings

since 1959, 91% of lightning incidents involvingdeaths had only one fatality. Lightning is a single-victim event.

Watches, warnings, statements, and advisoriesfor weather hazards ranging from thunderstorms toblizzards are issued to the public by the NWSthrough the media. Since lightning is so wide-spread and so frequent, it would not be possible toissue lightning warnings for every flash for eachperson. The responsibility of lightning safety mustbe shouldered by each individual.

Stories of surviving close lightning strikes,which are well publicized in the media, have leadto a wide public misperception of the risk of deathfrom lightning exposure. These misperceptionslead one to take risks based on casual attitudestowards lightning. There is a need for the public tounderstand basic characteristics of lightning e.g.how to identify safe shelter from lightning, andhow lightning travels along the ground andthrough water.

Using new knowledge about lightning, NSSL isleading an effort to collaborate with other groupsto develop educational resources aimed towardsinforming the public of lightning hazards andimproving planning for lightning avoidance.Flashes detected by the NLDN have been used todevelop climatologies that better define thelightning risk for several states including: Arizona,Colorado, Florida, New Mexico, Georgia andSouth Carolina. This information was even used,more specifically, to identify the lightning risk atvarious venues during the Summer OlympicGames in Atlanta. Climatologies for other statesare planned. Another study is using NLDN data to

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NSSL BriefingsA newsletter about the employees and activities of the National Severe Storms LaboratoryVolume 2 No. 2 Winter 1998

In Brief.....

News Briefs 2

Support staff 3

MEaPRS 4

Spotlight:J.T. Johnson 6

Tornado forecastanniversary 7

Excerpts from "TheUnfriendly Sky" 8

TIMEX 10

WDSS integration intoAWIPS 12

by Ron Holle, Raúl López, and Susan Cobb

Lightning is the most dangerous andfrequently encountered weather hazard thatmost people experience each year. Sum-

maries of weather-related fatalities continue toshow lightning as the second most-frequent killerin the United States (flooding and flash floodingare number one). The National Lightning Detec-tion Network (NLDN) shows that lightning strikesthe ground in most locations of the country eachyear. It also occurs every day in the summer andon all but a few days during the rest of the year.The NLDN locates an average of over 20 millioncloud-to-ground flashes a year in the U.S.! About100 people are killed and more than 500 areinjured by lightning every year-- and, in the U.S.

NSSL promotesimprovements inlightningeducation

Photo courtesy of Frankie Lucena who was photographing Jupiter from the south coast ofPuerto Rico. Jupiter is the white dot on the right edge of the picture.

Average annual number of storm-related deaths in theU.S. from 1966 to 1995

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NSSL Briefings Winter 1998

NSSL News Briefsfind the distances between successive flashes; this knowledge will improveplanning for lightning avoidance.

Recent studies of lightning victims revealed commonly-occurring highly-vulnerable situations and activities. For example, taking shelter under treeshas been found to be a widespread problem. A poster on this threat wasdeveloped in English and Spanish with Ken Howard of NSSL. Over 12,000copies have been distributed to teachers, NWS staff, and others. A large andgrowing portion of lightning casualties in the last few decades has occurredduring recreation and sports situations. We work with sports medicine staff atWilliam and Mary College and at East Carolina University to spread informa-tion about lightning, and we assisted in the development of a lightning policyfor sports that was recently published by the National Collegiate AthleticAssociation. A broader audience for soccer, baseball, and other leagues forschool children and adults also exists.

In addition, we are collaborating on guides and studies with medically-oriented people and others at the Lightning Data Center in Denver, its out-growth at the National Lightning Safety Institute, with medical staff at theUniversity of Illinois at Chicago and the University of Queensland in Austra-lia, and with staff members of the NWS at Chicago IL, Denver CO, Fort WorthTX, Medford OR, Melbourne FL, Sioux Falls SD, and Tampa FL.

We have also written papers with a science teacher for education publica-tions to bridge the gap between textbooks that often do not treat new topics inweather, and the meteorological literature that tends to be too complex forgeneral science teachers. These articles describe the flash-to-bang method,lightning safety and other weather subjects, and received a wide positiveresponse. They have been published in The Earth Scientist of the NationalEarth Science Teachers Association, and in state teachers magazines forIllinois and Indiana.

It is important that research results are synthesized into concepts that areunderstood by the public. Presenting this information in various forms such asposters, policy statements, and educational materials seems to be effective.We also present talks to groups, with an emphasis on speaking to educators inorder to reach as many people as possible. As expected, interviews with themedia have become frequent during the spring and summer, and the effects oflightning are receiving more visibility: Lightning is highlighted at the "Powersof Nature" exhibit that recently opened at Philadelphia's Franklin Institute. Wehope that our efforts with collaborators will reduce the number of lightningvictims.

Erik Rasmussen, a Research Meteorologist withNSSL and the Cooperative Institute for Mesos-cale Meteorology Studies (CIMMS), hasreceived the Presidential Early Career Award forScientists and Engineers. This is the highesthonor bestowed by the U.S. Government uponoutstanding scientists and engineers at thebeginning of their careers. Erik is one of 60chosen for the award, which gives him $10,000a year for the next five years to conductindependent research of his choosing.

Erik was honored for his work to plan anddirect VORTEX, a field experiment designed toimprove tornado predictions and warnings bystudying them at close range. He is currently amember of SRAD at NSSL facilities in Boulder,Colorado.

The American Meteorological Society'sMeisinger Award was given to DaveStensrud, NSSL Meteorologist, during aceremony at the AMS Annual Meeting inPhoenix, AZ. Dave was recognized for hisinnovative research into the structure,dynamics, and predictability of mesoscaleconvective systems and their impact on largerscale weather patterns.

NSSL scientist receivesPresidential Award

AMS's Meisinger Awardgoes to NSSL scientist

NSSL's VORTEX web pagevoted best in OARAt the NOAA Webshop at EnvironmentalResearch Lab headquarters in Silver SpringMD, NSSL was awarded first place for havingthe Best Webpage in Oceanic and AtmosphericResearch located at: (www.nssl.noaa.gov/noaastory). This webpage is a prototypedeveloped by Ann McCarthy and JoanO'Bannon to become part of the recentlyrevised NOAA Homepage. It is the first in aseries of "NOAA stories" that will be developedby various ad hoc groups to tell some of theinteresting stories within NOAA as part of anaccelerated outreach effort. In this case,"VORTEX, Unraveling the Secrets" tells the"true" story about tornado intercept using theVerifications of the Origins of Rotation inTornadoes Experiment project as an example.

u For more information contact Ron Holle at: [email protected] orRaúl López at [email protected]

Most people are faced with a large number of acronyms every day.We pay taxes to the IRS, mail things through the USPS, UPS,FedEx, and others, and when we get home from work we turn on

the TV to watch ABC, CBS, CNN, or NBC. We here at NSSL, an ERL labunder the OAR umbrella and part of NOAA which is a branch of the DOCrealize that this acronamia is unavoidable.

In this issue of NSSL Briefings we define at least 26 acronyms, and they areused 46 times on the first two pages alone. With no strict rules on how tohandle acronyms, the task of defining each one is laborious. So, in this andfuture issues of NSSL Briefings, we will try to have a short section at thebeginning of the newsletter where we define the most commonly used acro-nyms. We will call the section "AUITI" , or "Acronyms Used In This Issue."We hope you find it helpful.

On acronyms. . .

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NSSL STAFFDirector...............................................................................Jeff KimpelDeputy Director...............................................................Doug ForsythChief, MRAD.......................................................................Dave RustChief, SRAD.........................................................................Mike Eilts

NEWSLETTERExecutive Editor....................................................................Mike EiltsWriter/Editor.....................................................................Susan Cobb

NSSL Briefings is a publication from the National Severe StormsLaboratory (NSSL) intended to provide federal managers, staff, andother colleagues in the meteorological community with timelyinformation on activities and employees. If you would like to beadded to the NSSL Briefings mailing list, or have a change in youraddress, please forward requests to Kelly Lynn, NSSL, 1313 HalleyCircle, Norman OK, 73069; or email: [email protected].

In previous editions of NSSL Briefings, we have recognized thescientific divisions of NSSL: the Mesoscale Research and ApplicationsDivision and the Stormscale Research and Applications Division. The

accomplishments of these two divisions over the last several years has beenoutstanding, but another part of our team shares in these outstanding achieve-ments, and that is the staff assigned to the Director's Office. With a total staffof 19, the Director's Office includes the Central Support Services (CSS) group(bottom photo) and the Administrative group (top left photo) along with oneposition assigned to the Joint Operational Support Services Division of theUniversity Corporation for Atmospheric Research. Those in the Director'sOffice management are in the top right photo.

The CSS staff carries out numerous tasks that include computer hardwareand software support and maintenance, network support, data management,graphics support, library support, equipment maintenance and preventivemaintenance, World Wide Web support, outreach, public relations, andproperty management.

The Administrative staff also has numerous functions in support of NSSLthat include procurement, budget tracking and analyses, invoice and billing,payroll transmission, facility maintenance, safety, security, personnel actions,record keeping, supplies and secretarial support.

Our Joint Operational Support Services position supports and facilitates ourdata management efforts and field programs.

People are our most important resource. We have excellent people provid-ing outstanding support for our research and application programs. As wereflect on the past and look toward the future, let us remember the excellentwork that has been accomplished as a result of our outstanding teamwork.

Everyone contributes to our successes. Let us continue to work together, notonly internally, but externally, to improve the quality of our nation's severeweather forecasts and warnings.

OAR has awarded the Department ofCommerce's Bronze Medal to J.T. Johnson,DeWayne Mitchell, Phillip Spencer, Arthur Witt,Greg Stumpf and Pam MacKeen for their workin developing and transferring severe weatherdetection algorithms to the WSR-88D. J.T.Johnson, in addition to the team award, alsoreceived a Bronze Medal for his work with theOlympic Weather Support Office at the 1996Summer Olympic Games.

The Bronze Medal is granted to employeesand offices that have made contributions ofexceptional value in support of overall Depart-mental goals that serve the nation.

SRAD team receives DOCBronze Medals

NSSL News Briefs

NSSL's web site can be found at: http://www.nssl.noaa.gov

by Doug Forsyth, Deputy Director

Support staff integral partof the NSSL team

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AUITI (Acronyms Usedin this Issue)NLDN - National Lightning Detection NetworkNWS - National Weather ServiceAMS - American Meteorological SocietyNOAA - National Oceanic and Atmospheric AdministrationERL - Environmental Research LaboratoriesOAR - Office of Oceanic and Atmospheric ResearchVORTEX - Verifications of the Origins of Rotation in Tornadoes

ExperimentMRAD - Mesoscale Research and Applications DivisionSRAD - Stormscale Research and Applications DivisionCSS - Central Support ServicesWDSS - Warning Decision Support SystemAWIPS - Automated Weather Information Processing SystemWWW - World Wide WebDOC - Department of CommerceNASA - National Aeronautic and Space AdministrationOU - University of OklahomaSPC - Storm Prediction CenterNCAR - National Center for Atmospheric Research


Figure 3: NSSL's Cimarron radar (CIM) will obtainmeasurements of polarimetric quantities along withreflectivity and Doppler velocities.

by Conrad Ziegler

Mesoscale Convective Systems (MCSs)are large complexes of thunderstormsthat account for over half of the annual

warm-season precipitation in the United States eastof the Rocky Mountains. MCSs generate frequentcloud-to-ground lightning and additionally mayproduce severe weather including hail, tornadoes,and strong straight-line winds. Hence, MCSspresent a major public safety concern owing toeffects on flooding, agriculture, transportation,communications, and property. NSSL is planninga field experiment called the "MCS Electrificationand Polarimetric Radar Study" (MEaPRS), toinvestigate polarization radar signatures andelectrification processes in MCSs. In July 1997,NSSL hosted a meeting with collaboratingscientists from Colorado State University, theUniversity of Mississippi, Texas A & M Univer-sity, the University of Oklahoma, NASA/MarshallSpace Flight Center (MSFC), National Center forAtmospheric Research (NCAR), the Los Alamos

National Laboratory (LANL), and the AtlanticOceanographic and Meteorological Laboratory(AOML) to refine the scientific focus forMEaPRS. An operations plan for MEaPRS (http://www.nssl.noaa.gov/projects/meaprs) is presentlynearing completion.

MEaPRS will be conducted over the Oklahoma-Texas-Kansas region during the period from 15May to 15 June 1998, seven days a week, using anarray of fixed and mobile sensors to simulta-neously sample a target MCS (Fig. 1). Thesespecial mesoscale observing facilities include a P-3 Orion "hurricane hunter" aircraft (Fig. 2),operated out of Oklahoma City by the NOAA/Aircraft Operations Center (AOC), the NSSLCimarron radar (Fig. 3), and several mobilelaboratories (Fig. 4a) from which atmosphericsounding profiles of the MCS will be obtained

Figure 1: Operational domain of the MEaPRS experiment. Cross-hatching denotesthe area of combined 100 km-in-range coverage of CIM and the Oklahoma City(KTLX) and NEXRAD-OSF (KCRI) WSR-88D.

Figure 2: The P-3 (NOAA-42) will make in-situmeasurements of pressure, temperature, humidity, andwinds (i.e. “state variables”), while also sampling cloudand precipitation content. The helically scanning tailradar alternately points ahead of and behind the aircraftaxis, thus providing crossing or “pseudo-dual Doppler”wind and reflectivity measurements as the P-3 fliesthrough the storm.

NSSL plansfield experimentto study MCSs

MEaPRS will beconducted overthe Oklahoma-Texas-Kansas

region from May15 to June 151998, sevendays a week.

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Figure 4a: A mobile laboratory.

Figure 4b: Each mobile laboratory will release alinked “train” of instrument packages for measuringatmospheric profiles of temperature, humidity, winds,electric field strength, and other cloud properties.

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(Fig. 4b). A lightning mapping system willprovide detection of all in-cloud and cloud-to-ground flashes produced by a target MCS.

A typical operations day in MEaPRS will beginwith the preparation of a forecast for deep convec-tion and MCSs for the current day and an outlookfor MCSs for the following day over the targetregion. During the afternoon, nowcasters (short-range forecasters using observations) will monitorthe initial convection, and the P-3 and mobile labswill be vectored toward the developing MCS.Both forecasting and field coordination will beconducted from the Science Support Area jointlymaintained by the National Centers for Environ-mental Prediction (NCEP)/Storm PredictionCenter (SPC) and NSSL. The nowcasters willremain on duty through the night, passing informa-tion on MCS location, movement, and evolution tothe P-3 and mobile labs in the field. The P-3 willperform multiple horizontal passes and ascent ordescent soundings, both ahead of the leadingconvective line and within the trailing, non-convective or stratiform precipitation region of theMCS. In close coordination with the P-3 legs,soundings with the balloon-borne electric fieldmeters will also be obtained within the leading-lineconvection and the trailing stratiform region. As atarget MCS moves into the central Oklahoma area,polarization measurements of the MCS will becollected by the Cimarron radar. A typical MCSmission may last around seven hours, endingsomewhere between midnight and sunrise thefollowing morning.

The MEaPRS data set will be used to advanceNOAA’s forecasting and warning capabilities by:l determining the usefulness of polarization

radar to identify precipitation types and intensity

(this will set the stage for a possible upgrade of theWSR-88D network to include the polarizationdetection capability);l refining conceptual models of how thunder-

storms and MCSs develop charges and electricfields strong enough to produce lightning;l developing new conceptual models to explain

how MCSs form, move, and change their rainfallrates and airflow circulation intensities.

These advances in understanding and monitor-ing MCSs will assist the NWS by setting the stagefor improved forecasts of dangerous flash floodingand hazardous cloud-to-ground lightning.For more information, contact Conrad Ziegler at:[email protected]


to find a school. He decided to attend HendersonState University to work on the basics whilecontinuing to check out colleges that offeredmeteorology. J.T. had not even considered comingto OU until his dad, while teaching a week-longcourse in Norman, investigated the meteorologyprogram. His dad insisted that he take a look thenext week. J.T. says, "I was sold in 10 minutes."He transferred to OU after his first semester andearned his B.S. and M.S., working at NSSL theentire time. NSSL hired him full time in 1992.

A career-defining experience and a "crowningsuccess," J.T. says, was his participation in the1996 Summer Olympic Games in Atlanta, GA.He moved his family to Atlanta and spent 20months helping set up the Olympic WeatherSupport Office (OWSO) and providing expertiseon NSSL's Warning Decision Support System(WDSS). He was also able to help with hardware,software, and forecaster training for the OWSO.J.T. loved being involved in everything fromdefining what new variable needed to be added tothe database to how many people need to be onshift to cover storms. "It was the ideal situation formy left-brain, organized personality -- I helpeddefine the goals, develop a strategy, work on theproject for 20 months, finish the project, and claimthat it was a success."

His experiences in Atlanta helped J.T. betterdefine his career goals: to further develop therelationship between research and operations. As aresult, one of his current roles is to dialogue withthe weather service community to find out whattheir needs are from a severe weather warningperspective. With that information he helps director redirect research strategies and tool develop-ment at NSSL. J.T.'s second role is in the broadarea of applications development. The develop-ment of NSSL systems, such as WDSS andWATADS and development of applications forAWIPS are under his management. A third role isto find out how people are using the tools thatNSSL has developed and determine what can bedone to improve them.

About his life away from the lab J.T. says, "Idon't relax--I feel like I have to get a lot out oflife." He describes himself as in constant motion.He likes to spend as much time as he can with hiswife, Lori, and their two sons Ryan (3 1/2) andKyle (1 1/2). J.T.'s other activities include Biblestudy, maintaining a web page for his church,playing softball, and skiing. He sees himself as a"pretty positive person" and likes to "find good ineverything." Amazed as he is at the process, it isevident to J.T. that he met the right people at theright time and ended up in the right place.

Employeespotlight

by Susan Cobb

Bio Box

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J.T. Johnson

J.T. Johnson is still amazed how he got here--"Things just seemed to happen the right way."Mike Eilts, SRAD Chief, hired him when he

was a sophomore in college to work on a variety ofprojects including researching downbursts andmicrobursts. But being hired wasn't the amazingthing: It was how he ended up in Oklahoma in thefirst place.

J.T. grew up watching the weather from theoutfield of his high school baseball team inArkansas. "I had a lot of time to stand around," hesays. When he graduated, he thought he mightpursue meteorology, but the job potential seemeduncertain. J.T. had spent a little time at the NWSin Little Rock, AR, but he admits he didn't have afeel for research. But, first things first, he needed

Current position: Team Leader, NWS Liaison/Real-time Application Prototyping and Idea DevelopmentTeamCurrent pr oject: WDSS integration into AWIPS anddevelopment of a prototype AWIPS applicationEducation: B.S. Meteorology, 1989University of OklahomaM.S. Meteorology, 1992 University of Oklahoma


The Golden Anniversary Celebration will also highlight theexciting future which lies ahead for integration of better scientificunderstanding and rapidly advancing computer systems intooperational meteorological forecasting.

Since NSSL and SPC in Norman are direct descendants of thefirst tornado forecast 50 years ago, special events will be sched-

uled highlighting severe weather researchand forecasting. Special tours of NSSLand SPC will be available for interestedgroups. Included in the tours will be theopportunity to view SPC forecasters atwork issuing severe thunderstorm andtornado watches for the U. S. A number ofdistinguished guests are invited toparticipate in the ceremonies including theSecretary of Commerce, NOAA Adminis-trator and Directors of the NWS andOffice of Oceanic and AtmosphericResearch, officials from Tinker AFB andDirector of the U.S. Air Force WeatherAgency. Invitations have also beenextended to the Vice President, federal,state and local elected officials, andconstituents.

For latest information about the celebration, use the internet toaccess the Golden Anniversary of Tornado Forecasting homepageat: http://www.nssl.noaa.gov/GoldenAnniversary/ Come join usin celebrating the Golden Anniversary of Tornado Forecasting: 50years of Service to the American Public.

by Charlie A. Crisp

On the evening of March 25, 1948, a tornado roaredthrough Tinker Air Force Base, Oklahoma, causingconsiderable damage, a few injuries, but no fatalities.

However, the destruction could have been much worse. A fewhours earlier Air Force Captain Robert C. Miller and MajorErnest J. Fawbush correctly predicted that atmospheric conditionswere ripe for tornadoes in the vicinity ofTinker AFB. This first official tornadoforecast was instrumental in advancing thenation's commitment to protecting theAmerican public and military resourcesfrom the dangers caused by naturalhazards.

On March 23-25, 1998, NOAA's NWS(including the SPC, Norman ForecastOffice, and WSR-88D OperationalSupport Facility) and NSSL, in coopera-tion with the University of Oklahoma,Tinker AFB and the U.S. Air ForceWeather Agency will host an extendedcelebration in Norman, Oklahoma, and atTinker AFB as a tribute to the first 50years of tornado forecasting. Thiscelebration will recognize the milestonesin tornado forecasting over the past half-century, including therapid advancements in severe weather watches and warnings thathave been realized during the past few years through newobservational systems (WSR-88D, GOES), increased knowledge,and better interactive computer systems (AWIPS).

50th Anniversary of the first tornado forecast

to be celebrated March 23-25, 1998

Fawbush and Miller, 1951. Photo courtesyof Take-Off, Tinker AFB newspaper.

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Transcribed by Charlie A. Crisp from parts of anunpublished manuscript (written middle to late1970's)

I was assigned forecasting duty in the TinkerAir Force Base Weather Station, undercommand of Major E. J. Fawbush, on the

first of March 1948. The evening of March 20th,while on the evening shift, I was rudely awak-ened to the sometimes vicious vagaries ofMother Nature. There were two of us on shiftthat night. My backup forecaster was a StaffSergeant, also new to the T inker WeatherStation. In course of idle conversation we foundwe had much in common - we were both fromSunny Southern California and had no weatherexperience in the Midwest portion of the UnitedStates. We analyzed the latest surface weathermaps and upper charts and arrived at the sageconclusion that except for moderately gusty

Excerpts from "The Unfriendly Sky"by

Robert C. Miller, Colonel USAF-Ret

by Jeff Trapp

The Central Oklahoma Chapters of theAmerican Meteorological Society andthe National Weather Association will

conduct a scientific symposium on tornadoforecasting and research on March 24, 1998, onthe University of Oklahoma campus in Norman,Oklahoma. This is one of several activitiesscheduled for the three-day celebration of the 50thAnniversary of the First Tornado Forecast,sponsored by the Oklahoma Weather Center andTinker Air Force Base (see related article byCharlie Crisp). Nine internationally-recognizedscientists will deliver invited presentations ontopics ranging from tornado forecasting techniques

Tornado forecastingand research symposium

Nineinternationally-

recognizedscientists willdeliver invitedpresentations

and future activities of the Storm Prediction Centerto the history of storm and tornado interceptefforts. In addition, a tribute to Air Force Col.Robert Miller will be paid by Dr. Robert Maddox,who will also discuss the first tornado forecast ofMiller and Maj. Ernest Fawbush.

Registration forms and additional informationcan be found on the World Wide Web at http://www.nssl.noaa.gov/symposium or requested [email protected] or Tornado Sympo-sium, c/o NSSL, 1313 Halley Circle, Norman, OK73069. Early registration is encouraged becauseseating is limited. u

surface winds, we were in for a dry and dullnight. We were not astute enough to note thatthe upper-air analyses, received in completedform over the facsimile net from the USWB inWashington, depicted erroneously analyzedmoisture fields. We issued a Base warning forgusty surface winds up to 35 mph withoutthunderstorms, effective at 9 p.m. local time.

Shortly after 9 p.m., stations to our west andsouthwest began reporting lightning and by 9:30thunderstorms were in progress and, to oursurprise, detectable only twenty miles to thesouthwest of the Base. The Sergeant begantyping up a warning for thunderstorms accom-panied by stronger gusts even though we weretoo late to alert the Base and secure the aircraft.At 9:52 p.m. the squall line moved across WillRogers Airport 7 miles to our west southwest. T oour horror they reported a heavy thunderstormwith winds gusting to 92 miles per hour andworst of all at the end of the message, “TOR-NADO SOUTH ON GROUND MOVING NE!”

The rest of this story can be found on the webat: http://www.nssl.noaa.gov/GoldenAnniversary.


Monday, March 23: Open House at NOAA'sfour facilities in Norman.

Tuesday, March 24: The local chapter of theAmerican Meteorological Society and the NationalWeather Association will sponsor a scientificsymposium at the University of Oklahoma (OU).The symposium will be followed by a celebrationdinner Tuesday evening at OU.

Wednesday, March 25: All sponsors will host aspecial memorial dedication ceremony at TinkerAFB to commemorate the first tornado forecast,with the ceremonies concluding after lunch at theTinker Officers' Club.

Other items of interest associated with thecelebration:l the U.S. Postal Service is issuing a canceled

post card using the 50th Anniversary of TornadoForecasting logo as the cancellation symboll schools in Oklahoma are holding an essay

and poster contest on tornado safety as encour-aged by the Oklahoma Climate Survey'sEarthstorm Project.l Fly-over by aircraft from Tinker AFB.l A special edition of the AMS's technical

journal, "Weather and Forecasting", highlightingadvances in severe weather forecasting.l Participation by Chambers of Commerce of

the surrounding cities in central Oklahoma.l T-Shirts and baseball caps with the 50th

Anniversary of Tornado Forecasting logo should beavailable for purchase.

50th Anniversaryevents:

These damage photos of Tinker AFB from 1948 havebeen provided by the Tinker AFB historian

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Planning TIMEX:The Thunderstorm InitiationMobile Experiment

by Conrad Ziegler

Anticipating thunderstorm initiation is a very difficult and challengingproblem of considerable importance to both warm season quantitativeprecipitation and severe weather forecasting. To help improve the

accuracy and specificity of storm forecasts, NSSL scientists Jeanne Schneider,Conrad Ziegler, and Erik Rasmussen are leading the planning of the "Thun-derstorm Initiation Mobile Experiment" (TIMEx), a field study designed toinvestigate convective initiation on the mainland United States. Communitydiscussions of the proposed field study are taking place via an interactive webpage (http://www.nssl.noaa.gov/srad/timex). NSSL has organized two TIMExplanning meetings, the initial meeting hosted in Norman in November 1997and the second meeting held in Phoenix, Arizona in January 1998 during theAMS Meeting. The TIMEx planning meetings have brought together scien-tists from several universities, NCAR, other Oklahoma Weather Centerelements, the National Weather Service, and other federal laboratories todiscuss hypothesized convective initiation processes and the observationalstrategies required to detect those processes in actual cases. We intend forTIMEx to be one of a series of field programs designed to answer specificquestions about the life cycles of storms and Mesoscale Convective Systems(MCSs). (See also the article on the "MCS Electrification and PolarimetricRadar Study - MEaPRS" page 4 in this issue.) As realized in TIMEx we beginwith a focus on convective storm initiation.

Figure 2: Radars capable of measuring clear air velocity are key mobile sensorsproposed for deployment during the TIMEx experiment. The "Doppler-on-Wheels"radar is operated under a cooperative agreement between the JMRF and the NationalCenter for Atmospheric Research (NCAR). Coordinated measurements from two DOWradars that have been deployed near boundaries will permit finely resolved analyses ofthe evolution and spatial structure of airflow in the planetary boundary layer.

Figure 1: Photograph looking north at newly-developing deep dryline convection at 0040 UTC on 16May 1991 during the COPS-91 field experiment(courtesy C. Hane, NSSL). The NSSL-2, a mobileballooning laboratory operated by the Joint MobileResearch Facility (JMRF) of the Oklahoma WeatherCenter, is in foreground while a developing WheelerCounty, Texas storm is in background. Valuableexperience gained from COPS and the later VORTEXproject on obtaining mobile soundings and otherobservations both preceding and near developing stormswill be applied during TIMEx.

TIMEx is a field study designed toinvestigate convective initiation on

the mainland United States.


more comprehensive TIMEx field phase will beconducted. Though the site of the preliminaryfield phase has not been firmly decided upon, thescientists attending the planning meetings favoredthe Texas-Oklahoma-Kansas region owing to theexcellent visibility for ground-based mobileDoppler radar observations and the possibility ofutilizing dense observing networks already inplace on the U.S. Southern Plains.

In TIMEx we plan to collect data on as manytypes of boundaries aspossible, includingstationary fronts, warmfronts, outflowboundaries, drylines,and the myriad ofother low-altitudefeatures detectable asradar fine lines inWSR-88D reflectivitydata but of unknownorigin and character.Additionally, a varietyof low-altitude shear, temperature, and humidityregimes will be sampled. Analysis of this uniqueset of observations will assist the NWS by provid-ing the basis for conceptual models of the convec-tive initiation process that in turn will helpimprove forecasts of storm development.

One of the fundamental issues in precipitationforecasting is the timing and location of theinitiation of storms, or in many cases, the failure ofinitiation. Clearly, any precipitation forecast willfail completely if initiation is forecast and fails tooccur, and vice versa. Further, quantitative errorsare strongly dependent on errors in the locationand time of storm initiation. Moreover, largeerrors in forecast temperature may be caused bypoor forecasts of storm development. Recent casestudies of seabreeze lines, drylines, and othersharply defined zones of contrasting winds,temperature, and moisture near ground havedocumented how airflow convergence and liftingof moist air along such "boundaries" can initiatestorms (Fig. 1). Atmospheric airflow disturbancessuch as gravity waves or strong, localized aircurrents known as "jet streaks" may help triggerstorms along boundaries by providing additionallifting of moist, unstable air. Strong vertical windshear and mixing of moist rising air with drier airfrom higher in the atmosphere may limit thetendency to achieve water saturation and cloudformation, thus suppressing the development ofdeep convective clouds and storms. None of theseprocesses are adequately understood, and may bemisrepresented or completely unresolved inmesoscale numerical weather prediction models.

The plan for TIMEx is to conduct a relativelysmall, very focused field experiment as early as thespring of 2000 to document structure and morphol-ogy of the planetary boundary layer and lowertroposphere on spatial scales from 2-20 km in thehorizontal dimension. Various remote and in-situmeasurements from mobile platforms will beconcentrated in areas with the potential for deep,moist convection. Airflow in the optically clearplanetary boundary layer will be detected withexisting sensitive airborne and ground-basedDoppler radars (Fig. 2), while "lidars" (laser lightDoppler radars) that measure water vapor contentbased on a differential water vapor absorptionprinciple must be developed for mobile applica-tion. Following a year of analysis of data collectedduring the preliminary field phase, a second and

The NCAR Electra aircraft carries the ELDORA (Electra DOppler RAdar) Dopplerradar, which provides a demonstrated clear air wind field mapping capability. TheELDORA antenna is contained within the “rotodome” assembly mounted behind theElectra’s tail section, allowing ELDORA to effect volume scans by rotating throughcomplete 360 ° sectors at an angle to the flight path of the Electra. The ELDORAradar will be flown in various rectangular patterns oriented along boundaries capableof initiating storms.

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For more information contact Conrad Ziegler at:[email protected]

In TIMEx we plan to collect data onas many types of boundaries aspossible, including stationaryfronts, warm fronts, outflow

boundaries, drylines and a myriadof other low-altitude features.

components have examined them from all possibledata sources. Then, a forecaster wishing to havemore information, can examine data and algorithmproducts using data and products from all indi-vidual radars that scan the storm. We term thisapproach to information presentation as selectivedisclosure.

In addition to the new CWA-centric warningguidance information, the WDSS integration intoAWIPS will include trend displays of new vari-ables not currently available in the operationalWSR-88D displays. Over the past several years,NSSL has demonstrated the utility of using timeseries of variables or trends of certain phenom-enon-specific parameters for making warnings.Some of these trends have been incorporated intothe WSR-88D system. However, it is possible todisplay many more useful parameters as trends.These additional trends will be added during theWDSS integration into AWIPS.

Initial integration activities are expected tobegin in early 1998 and be completed by the endof 1998, resulting in a limited WDSS functionalityas part of AWIPS Build 6.0 (Build 3.0 wasreleased to the field in August, 1997). Build 6.0 isexpected to be released to the field in mid-1999.Plans are to continue to add more WDSS function-ality to AWIPS beyond Build 6.

NSSL Briefings National Severe Storms Laboratory . 1313 Halley Circle . Norman, OK . 73069

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WDSS integration into AWIPSwill bring some changesby J. T. Johnson

The National Weather Service and NSSLhave agreed to incorporate unique compo-nents of the Warning Decision Support

System (WDSS) into the Automated WeatherInformation Processing System (AWIPS).

One component to be integrated will be thesevere weather table, used by forecasters tosupport their decision making. The table informa-tion in the prototype WDSS consists of severeweather prediction and detection algorithminformation from a single radar that is sorted andcolor-coded by severity. During the integrationinto AWIPS, the tabular information will betransformed into a County Warning Area, or CWA-centric rather than a radar-centric set of informa-tion. The reason for this change is that most NWSForecast Offices have an area of responsibility forissuing warnings- their CWA- that is covered bymore than one radar. Therefore, the warningguidance information should include informationfrom all relevant WSR-88D's, not just the primaryone. The new CWA-centric information will takeinto account such things as the range a storm isfrom a radar, the viewing angle the radars have ofthe storm, and the scanning strategy the radars arein. Given this new set of information, the fore-caster will be able to determine quickly the mostsignificant storms, knowing that the WDSS

In October 1997, Loretta McKibben wasnamed by the Jet Propulsion Lab and NASA tobe Oklahoma's first "Ambassador to Jupiter"

in a public educational outreach program for theGalileo spacecraft to Jupiter. Two ambassadors arechosen from applicants in each state to provideeducational activities and workshops for studentsand teachers and host public speeches and activi-ties to inform the general public about knowledgelearned from Galileo. Two public events havebeen held so far with four more planned in 1998,

NSSL's Ambassador to Jupiterin addition to workshops for teachers and studentsin Oklahoma school systems. Loretta and NSSLare sponsoring the "Weather Around the SolarSystem" home page on the WWW as a part of thisproject (http://www.nssl.noaa.gov/srad/solarsystem), which compares and contrasts theweather patterns and weather phenomena ofplanets in our solar system that haveatmospheres. u

One componentto be integrated

will be thesevere weathertable, used byforecasters tosupport their

decisionmaking

winter 1998 nssl briefings volume 2 no. 2 winter...

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