1. (PI: Peter Ojiambo) NCSU, Department of Plant Pathology August 8, 2014
Forecasting Cucurbit Downy Mildew Outbreaks in Eastern North America Thomas Keever
(PI: Peter Ojiambo)
NCSU, Department of Plant Pathology
In conjunction with the NC State Climate Office and many others
August 8, 2014

2. Cucurbit Downy Mildew on Cantaloupe

3. Why are we here?
The goal of the forecasting effort is to help the cucurbit growing community manage the CDM epidemics by supporting …
Research – determining how the epidemics move and tracking their progress
Extension – providing important information that enables the growing community to make better decisions in the most timely fashion
Education – in various fields: biology, pathology, epidemiology, meteorology, etc. via the forecasts themselves and the historical record.

5. Dispersal Transport Deposition
Atmospheric Transport of Spores (Transport Event)
Distance
(1-5,000 km)
Atmospheric Boundary Layer
Rainout &
Washout
Sedimentation
Height (1-3,000 m)
SOURCE
STRENGTH
SURVIVAL
INFECTION
Ground Level
Dispersal
Transport
Deposition

6. Point source release. Bulletin of the American Meteorological
Society Vol. 80 Jan 1999

9. Aerobiological Factors
Spore Production (Source Strength) Transport and Survival Deposition Infection

10. Source size / Incidence / Severity Morning humidity (spore release)
Spore Production / Source Strength
Source size / Incidence / Severity
Recent rainfall
Overnight humidity
Temperature
Morning humidity (spore release)
Derived from Disease Reports / Source-Site Observations, Weather Observations, Forecaster Evaluation

11. Dispersion simulations
Transport and Survival Where is the event going? How many spores will survive? Atmospheric trajectories
Dispersion simulations
Cloud cover Derived from ARL’s HYSPLIT, FLEXPART, Real-time Observations, NWS Forecasts, Forecaster Evaluation

14. Deposition and Infection What is the chance of precipitation
Deposition and Infection What is the chance of precipitation? In what manner will it occur? How much will fall? Current and forecast rainfall
Temperatures
Derived from Real-time observations, NWS / HPC forecasts, Forecaster Evaluation

16. Analysis / Evaluation / Combination / Synthesis How do you handle risk prediction for events with a variety of conditions? What happens when events from separate sources converge on a new region? Do the risk predictions make sense when considered as a whole? Derived from Forecasting Rules-of-Thumb, Forecaster Evaluation, and (sometimes brutal) Forecasting Experience

17. Presentation / Communication How can we get the word out?
How does one illustrate the Risk of Epidemic Spread to a diverse audience in a manner that maximizes usefulness and understanding and minimizes confusion and misinterpretation?
How can we get the word out?