1 Ted Keller Senior Meteorologist KOLR/KSFX-TV Springfield, Missouri The Functionality of a New Radar Software Package: GRLevel2 Analyst EditionTed KellerSenior MeteorologistKOLR/KSFX-TVSpringfield, Missouri
2 I’m from Springfield, Missouri Much of our “skyline” is due to this guyMissouri State UniversityPerhaps many of you may be more familiar with Branson, Missouri
3 This Presentation Why I decided to give this talk Review of AE software capabilitiesUsing AE in real-timeConsiderations for using AE on airEstablishment of a radar resource or dialog program (via a web site?)
4 My Radar Experience WSR-57C (first hook echo) Kavorus RADAC WSI 1010N (level 3, NIDS)Baron FasTrac Millennium
5 The NIDS Years Useful for quick diagnostic; storm attributes NIDS images poor quality; hard to “see” many featuresStorm attributes delayed from imagesStorm attributes not perfectThe whole NIDS set up discouraged any detailed analysis
6 Why This Talk?I’m excited! AE has opened a whole new world of radar analysisI come from background with no live radar experienceI’m certainly no radar expert but I believe I represent many of you with similar backgrounds and experiencesAE has improved severe weather coverage!
7 GR2 Analyst Edition (AE) AE reads Level II data from the NWS 88D radar (real-time or archived)It was designed as a volume-rendering tool allowing users to view radar data in three dimensions plus time (4D)AE is also a very slick 2D radar viewer with lots of useful features
8 GR2 Analyst Edition (AE) AE uses hail detection algorithms patterned after those developed by the National Severe Storms Lab (NSSL)The environmental data used by the algorithms can be entered by hand or automatically input using RUC objective analysis dataAE generates two hail parameters:POSH, Probability of Significant HailMEHS, Maximum Estimated Hail Size
9 GR2 Analyst Edition (AE) The user can input storm motion vectors used in the calculation of storm relative velocity (SRV)AE calculates vertically integrated liquid (VIL) density (VILD)VILD takes the entire storm height into consideration and uses all reflectivity (including hail) in its calculation
10 AE 2D Fields Base reflectivity (BR) Base Velocity (BV) Storm Relative Velocity (SRV)Spectrum Width (SW)Echo Top (ET)Vertically Integrated Liquid (VIL)Vertically Integrated Liquid Density (VILD)Probability of Significant Hail (POSH)Maximum Expected Hail Size (MEHS)
11 2D Features Elevation scan selection Derived products Screen markers Storm motion vector2D “slice”Placefiles and shapefilesExporting images
12 Note: the radar data is level 3 in this example Place and Shape FilesNote: the radar data is level 3 in this example
13 The Volume Rendering Engine Four viewable fields:Base reflectivityBase velocityStorm relative velocitySpectrum widthAllows storms to be viewed in three dimensionsTwo modes:Lit Surface, uses an alpha table to produce semi-transparent dBZ surfacesIsosurface, users can step through dBZ levels
14 Lit Surface Example Solid 50 dBZ surface (red) What is this?Solid 50 dBZ surface (red)Semi-transparent 45 dBZ “shell” (gold)
15 Isosurface Example An externally produced animation showing successive layers of dBZ being stripped away
16 3D Alpha TableUsers can select which dBZ levels are visible and their degree of transparency by manipulating an alpha color tableSolid above 50 dBZ“shell” at about 45 dBZ
18 Where Are the Attributes? At present, there are none in AEThe issues are what to offer and how to display it, not whether it should be doneVelocity data: noisy data subject to aliasing issues
19 Current Cut-In Policy Definite: Subjective: At least one live cut-in for all tornado warningsSubjective:“Preemptive Strike”: a cut-in for a storm likely to become tornadicOngoing coverage of tornado warnings that fall short of “wall-to-wall”Most severe thunderstorm warnings are not covered with a cut-in
20 Preemptive/Ongoing Tornado Coverage Just using AE in 2D with Level II data is a huge improvement!!In 3D, features such as BWER’s are plain to seeWhat about the “tornado finger”? (“fickle finger of fate”)AE definitely aids the decision making process
21 Noteworthy 3D Features Tornado tube Hail cores Bounded Weak Echo Regions (BWER’s)OverhangsTriple BackscatterOvershooting Tops
22 An Example of a Three Body Scatter Spike (TBSS)
23 Non-Tornadic StormsCut-in decision based on general storm intensity, weighed heavily by population density!Can AE provide enough detailed storm information to justify more cut-ins for non-tornadic events?
24 Finding Hail Cores in 4DAE makes it easier to visualize developing and descending hail cores using the volume rendering engineAE also has sophisticated hail probability and estimated hail size algorithms
26 Hail Size - MEHS Tennis Ball (2.5”) sized hail near Moody, MO AE estimated 2.76” 4 minutes before the reported time of the hail
27 Using AE On-AirIt should first be stated that AE in its present form was not designed specifically for on-air useIf future builds lean in this direction, there are only two considerations:Would AE add meteorological value?How does it look? Is it understandable?
28 Just the FactsI tend to lean toward the “Joe Friday” approach to live cut-ins meaning I believe the public is best served by clear graphics which state what, where and whenOn the other hand, this is TV and where would we be without a certain level of enthusiasm for new products and visualization techniques?
29 How Does it Look? Is it Understandable? AE has done a great job giving the user graphical options to make the product look fantastic!Will viewers understand what they are looking at? Perhaps.Need accurate geographical reference pointsMust be selective about what to show and careful in your explanationFor stations already committed to 3D radar views, AE is an improvement!
30 Would AE Add Meteorological Value? This is a tougher questionA few candidates:Timing of hail core descentTornadic signaturesOther undiscovered signatures
31 Future Investigations and Projects Database of hail size verificationNew 3D structures or signatures?New 3D velocity structures or signaturesConvincing management to invest in a stand alone computer for proper on-air testingEstablishing a radar resource web site
32 Helical FlowExample of twisted inbound/outbound couplet in 3D velocity dataNew signatures here? I don’t know, I’ve never seen images like this before, real-time or otherwise.
33 Level 2 Radar Data (not a comprehensive list!) Allison House (placefiles and data)University of Iowa (non-commercial)National Climate Data Center (archive only)