Morphologic Investigation of Thunderstorm Initiates and GIS Attributes with Testing for Improved Operational Nowcasting of Thunderstorms & their Severity in New Jersey Dr. Paul Croft 1, Alan Cope 2, Danielle Fadeski 3, Alexis Ottati 3, Jackie Parr 3 Faculty Research Advisor 1 National Weather Service 2 Undergraduate Student 3

Why Improve the convective initiation forecast? What We Forecast…What Really Happens… “…a 40% chance of showers and thunderstorms…”

Convective Objectives Determine Convective Initiation patterns PHI CWA and nearby region Movement, Intensity and Coverage Use online database to assist in enhanced operational forecasting of thunderstorm initiation, coverage, and severity in real-time Establish operational archive and forecast database

Data Collection & Methods Study Period: 2000 – 2010  10 Summer Seasons: June, July & August (one test season) Mapped daily radar every 3 hours between 12 UTC and 00 UTC  Recorded cell/area radar intensities of 30 & 50 dBz Classification of each day and identify initiation locations/patterns  500mb flow, surface synoptic pattern, and combinations of the two Classification of Convective Activity for 1200 – 0000 UTC EventContaminateNull After 15 UTC Before 15 UTC No Activity Southwest Warm Front EventContaminateNull

Research to Operations: Thunder Dome  Preferred locations of initiation from archive  Empirical probabilities of occurrence developed  Critical threshold values and field patterns associated with activity  Discern an “E” from “C” or “Null” day with greater confidence  500 flow  Sfc Synoptic  Probabilities  Locations  CDC Diagnostics  Pattern of parameters  Causative Factors

Building an Operational Conceptual Model Determine 500 mb flow type (e.g., West flow cases) 500 mb flow- WEST Day TypeEventContaminateNull Sample Size % Chance38%30%32% 68% chance of initiation to occur with West flow

Forecasting with Operational Conceptual Model Determine Surface Feature (e.g., Cold Front) Surface Feature- COLD FRONT Day TypeEventContaminateNull Sample Size % Chance45%41%13% 86% chance of initiation to occur with surface cold front

Applying the Operational Conceptual Model Using a combination (500mb+Surface Feature)  e.g., West flow and Cold Front West-Cold font Day TypeEventContaminateNull Sample Size % Chance47%36%17% 83% chance of initiation with W-CF combination preferred region for initiation for event cold front and 500 mb flow Contaminate cold front cases show no preference for initiation location

Use of Diagnostic Patterns/Thresholds… PWAT Event PWAT Contaminate PWAT Null 32% Chance Event 64% Chance Contaminate4% Chance Null

Operational Testing & Verification Student: Match location to highest MOS POP axis & compare with gridded/zone Number sequence of cell initiation Outline areas of initiation; cells, areas, or lines & where for severe Date/Type: June 1, 2009/Event Indicate whether forecast day of interest will be: E, C, N & if Severe 1200 UTC 500 mb flow: NW Sfc Pattern: High P Severe: Yes Obs/PredictEventContaminateNull Event730 Contaminate270 Null404 How successful?  Lightning Data  STP for Coverage  Severe versus Non-Severe Time of ForecastSuccess Rate Previous Afternoon % Early Morning % Early Morning % Early Morning 2009/201081%

Develop a Lightning Climatology Event Days, SW FlowEvent Days, NW Flow Can break down hourly to show diurnal evolution… Can assist in verification and determining coverage/impacts…

What’s the pattern in time? Event Days, SW FlowEvent Days, NW Flow

What’s the Coverage of Convective Activity? (short term forecasting: 0-6h & 6-12h) Storm Total Precipitation (STP)  Consider the first (12-18z) and second (18-00z) halves of the day  See progression/development of cells after initiation locations Mapped values from website products  0.1 inch signifies “likely” precipitation related to day’s convection  1.0+ inches suggest thunderstorm with heavy rainfall and intensity/severity Composites of Coverage/Intensity  Suggests greater risk regions  Amounts and possible severe storms

What about probability/location of Severity? 48.5 % Severe Half E-COLD create Severe Weather 25.6% Severe One-fourth C-COLD create severe weather

Diagnosing Events: Non-Severe vs. Severe Non-SevereSevere Omega at 700mb for Cold Front EVENT days: Non-SevereSevere Omega at 700mb for Cold Front CONTAMINATE days: 00-09

GIS tie-in to Models & NDFD: Explaining Convection Use high resolution GIS-based grid with 1-km grid of study region with details of the forecast region and locations  Relate specific physiographic features in the area to the preferred locations of convective initiation and its severity  GIS grid calculations focus on land use and land cover, elevation, distance to coast, and slope and can be related to model output  Risk assessment and management; warning specificity & public information statements; visualizations in time and space  Automation and animation for response planning/preparation

GIS Assisted Convective Forecasting If we know the characteristics of the Grid Box (Elevation, Land Cover, Population, etc.) If we know the synoptic regime & 500mb Flow (SW CF, etc.) Combine this information with CDC composite variable or parameter values (PWAT, Omega, etc.) GIS Assisted Prediction of Convective Initiation characteristics, impacts, & risks

Summary & Conclusions Comprehensive Prediction of Convective Initiation  We know: Who, What, Where, How, When, & Why of initiation  We can: Distinguish Coverage and Intensity/Severity  Now Provide: Operational Products with Online Archive  Now Identify: Operational Conceptual Model & Cause/Effect Next: Refine, Enhance, Automate (GIS-based radar data) Future steps: GIS-grid assisted forecasting Future purposes: Risk assessment and management Acknowledgements Thanks to the Kean University Department of Geology & Meteorology Faculty & Staff, Student Majors, and Adam Gonsiewski, undergraduate student of Millersville University for their assistance with this project. This presentation was prepared by Kean University and the National Weather Service under a sub-award with the University Corporation for Atmospheric Research (UCAR) under Cooperative Agreement with the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce (DOC).