1. NCAR Research on Thunderstorm Analysis & Nowcasting
James Pinto & Wiebke Deierling
Lead Project Scientists
NCAR / Research Applications Laboratory
Disclaimer: This research is in response to requirements and funding by the Federal Aviation Administration (FAA). The views expressed are those of the authors and do not necessarily represent the official policy or position of the FAA.

2. Research in Thunderstorm Prediction at NCAR
Lightning Detection and Nowcasting
Predicting initiation of large convective storms
High Resolution Ensemble Post-processing
Data Fusion Techniques
Friends and Partners of Aviation Weather : 23 October 2013

3. Lightning Detection Uncertainties
Source A
Source B
Source C
LMA
DIA
“Lightning Truth Field” from Colorado Lightning Mapping Array (LMA) recently installed by New Mexico Tech University
Friends and Partners of Aviation Weather : 23 October 2013

4. Probabilistic Lightning Nowcasts
Nowcast utilizes WSR-88D radar data to monitor radar reflectivity characteristics above the freezing level.
Valid 30 min into future
Forecasts lightning in cores, anvil, initiation and mature phases of convection.
LMA
Friends and Partners of Aviation Weather : 23 October 2013

5. Storm Initiation Prediction
Satellite and VIL from MIT-LL CIWS
MIT-LL CIWS Extrapolation Forecast
2 hour movie of obs VIL satellite imagery shows rapid storm initiation and growth to over 100 km in length over Iowa
2 hour loop for extrapolation forecast does well with existing storms
But, does not give indication of new storm formation…..
Friends and Partners of Aviation Weather : 23 October 2013

6. High Resolution Ensemble Model Post-processing for CI Prediction
NOAA/GSD HRRR forecasts from different issue times valid at 22:00 UTC
HRRR Ensemble Storm Initiation Likelihood and Extrapolation Forecasts
12:00 utc
16:00 utc
CI Likelihood
High
17:00 utc
18:00 utc
Moderate
Image processing technique used in algorithm to identify LCS, determines which ones are initiation events.
Requires high-res ensemble data to get storm structure information.
Valid 22:00 utc
19:00 utc
20:00 utc
Friends and Partners of Aviation Weather : 23 October 2013

7. Data Fusion to Predict Storm Initiation
Terrain
HRRR CAPE
Statistical Data Mining using
Decision Trees
Satellite Trends
HRRR DPT
Satellite
HRRR RH / PSLV
Friends and Partners of Aviation Weather : 23 October 2013

8. Friends and Partners of Aviation Weather : 23 October 2013
Summary Points
Be aware that there are uncertainties in observations and nowcasts.
Focus of work in RAL on quantifying uncertainty in short term prediction of convection and its characteristics
Friends and Partners of Aviation Weather : 23 October 2013

9. Friends and Partners of Aviation Weather : 23 October 2013
Extras
Friends and Partners of Aviation Weather : 23 October 2013

10. Conveying Uncertainty
Confidence is generally described as the level of certainty that a hypothesis or prediction is correct.
Statistical definition – “The Confidence Interval provides a range of values that bracket the mean outcome at a given level of certainty.”
Probability is the likelihood that an uncertain event will occur.
95% confidence interval
Most likely category
Precip Category
P(7) = 16% -> ” in 3 hr period
Friends and Partners of Aviation Weather : 23 October 2013