Extreme Weather Events
Discussion Leaders—Robert Crane & Janet Gamble
Notes by Robert Swanson
What information products would you need to address this topic?
Weather events of greatest concern to planners and the general public:
- Hurricanes
- Convective storm events
- Rapid snowmelt
- Rainfall on frozen ground
- Severe ice storms
- Large-scale Nor’easters
- Droughts
- Tornadoes & strong wind events
Some of these were discussed with regard to what information people want as well as what type of information scientists and modelers conceivably could provide.
Hurricanes
Stakeholders want:
- Fact sheets on watches/warnings
- Frequency & severity information (in climate change scenarios)
- Storm track information
Short-term information, such as fact sheets and adaptation strategies for an impending storm already exist but need a better distribution system. However, due to the complex nature of hurricanes and the spatial resolution of climate models, no model is currently able to predict hurricanes. MARA might serve as a clearinghouse for historical severe events in the region. Resulting pattern recognition may improve predictions of frequency and better preparedness for future storms.
Convective Storm Events
Stakeholders want:
- Frequency & severity information (in climate change scenarios)
Twenty-five percent of the floods in the Susquehanna River basin are associated with convective events, and current trends show that more precipitation is coming in such events. Along with their strong winds and lightning strikes, convective storms can affect electricity availability. Improved ability to detect MCCs (Mesoscale Convective Complexes) would affect insurance premiums. The big question is whether these MCCs can be modeled, or are they too small in scale? Work being done with 100 mb divergence fields might fingerprint the development and movement of these storms.
Rapid Snowmelt/Rain on Frozen Ground
Two of this century’s three biggest floods in the Susquehanna River basin were rapid snowmelt events. In these events, water filtration plants get inundated by sediment, with the irony of being without water during a flood—this points out the need to regionalize water supplies to ensure access to clean water. Another consideration would be the health effects and disease vectors due to these flooding events. Modeling these events will require a model for storm tracks.
- What techniques would you use for disseminating information about the issue?
- PowerPoint presentations using web-available graphics, tailored to each audience. Use the historical climate record and assess the impacts if such events were to happen again.
- Grassroots efforts to enhance assimilation of "common sense" information (such as the need for flood insurance), congressional briefings
- Speakers bureau, articles to general journals and newsletters; improve accessibility of information.
Discussion:
- Is it practical to tailor talks to small civic groups?
- Product(s) must be very general—suitable for both congress and the lay public.
- Stress what is known and what is uncertain. Indexing climate change to ENSO and La Nina might be more relevant to the public, because people extrapolate personal experience with extreme weather to understand climate change.
Miscellaneous comments
- There may be a threshold of public awareness associated with the extent of disruption or costs incurred. They may not know, e.g., that ice storms and heavy snowfall are very detrimental to the forestry industry. Flooding restricts access to forests.
- Tornadoes and wind events are significant to electric utilities
- Extreme event information dissemination allows for real preparedness planning, which may be most effective if storm trends are NOT coupled with climate change discussions
- Positive aspects of climate change should be noted as well as negative. The decrease in winter’s severity and duration might extend the tourist season for southern portions of the MARA region.
- Will there be changes in public perception as climate change occurs; that is, will people become acclimated to a "rainy season"? How will human thresholds change?