# Presentation: 493069

## SAFETY, HEALTH AND ECONOMIC IMPACTS OF WEATHER AND CLIMATE IN THE URBAN ENVIRONMENT

- Raymond J. Ban
- The Weather Channel, Inc.

## MY MISSION TODAY

- Provide an overview of certain weather/climate events that when occurring in urban environments produce unique challenges and impacts.

## Selected Weather/Climate Events

- Winter Storm
- Heat Wave
- Flood
- Tropical Cyclone
- Wildfire

## WINTER STORM

- Urbanization results in:

- Increased threat for more damage and delays .
- Hundreds killed, tens of thousands injured in auto accidents.
- Millions marooned at home and work, disrupting commerce.
- Tremendous costs in road, rail and highway maintenance.

- Implications for the forecaster:

- Small events (such as a dusting of snow or a light glaze) can have a huge over a short period of time – information must be collected and communicated rapidly.
- Large snow events can impact tens of millions of people for several days to a week or more
- forecast lead time is important for industry and emergency management.
- Icing can result in power outages affecting millions.

**WINTER STORM**

**Notes:**
**Deaths during heat wave in Chicago: 465-739

## HEAT WAVE

- The Chicago heat wave of July 1995 caused somewhere between 465-739 deaths.  It was exacerbated by the urban heat island which keeps night-time temps warmer.

- Global Change Scenario:

- Very likely:  More hot days.
- Very likely:  Higher heat index.
- Likely:  Higher night time temperatures.
- Likely:  More heat waves.

**HEAT WAVE**

**Chicago Heat Wave**

**July 13-16, 1995**

- HIGH TEMP:  104° F (O’Hare)

- DEW POINT:  75° TO 82°F

- NIGHT-TIME TEMP: >75°

**U.S. WEATHER-RELATED DEATHS**

- AVERAGE PER YEAR

- (approx.)

- Hurricanes	          20
- Tornadoes	          60
- Flooding		          85
- Lightning                    70-100

-        **HEAT WAVES           235**

- Heat waves are the #1 weather related killer and are likely to increase.

**Notes:**
**Deaths during heat wave in Chicago: 465-739

## FLOOD

- Urbanization results in:

- Reduced infiltration of rainfall.
- Accelerated runoff rates.
- Artificial flood-control channels with excessive rates of flow (where children sometimes play).

- Implications for the forecaster:

- Reduced flash flood guidance values (lighter rain results in flooding).
- To have the desired warning lead time, sometimes must warn of flooding based upon rainfall in storms approaching area (before they arrive).
- In urban areas near mountains, must warn for rain falling over adjacent hills that will rush down streams and rivers (e.g., Las Vegas).
- Each new housing or business development changes the flood threshold and runoff characteristics of the urban watershed.

**FLOOD**

**Notes:**
**Deaths during heat wave in Chicago: 465-739

## TROPICAL CYCLONE

- Urbanization results in:

- Implications for the forecaster:

- “Warning – Response” model is stressed.
- Increased difficulty in evacuation due to road constraints.
- A flood catastrophe to inland urban areas from a tropical storm or hurricane could be as costly as impacts at the coast (e.g. tropical storm Allison).
- Increased demand for safe shelters.
- More boats in the water make more people vulnerable to marine impacts.

**TROPICAL CYCLONE**

- Lead time
- Lead Time
- Lead Time

**Notes:**
**Deaths during heat wave in Chicago: 465-739

## WILDFIRE

- Urbanization results in:

- Increasingly expanding housing areas into hilly, wooded suburbs.
- Many communities in the West are in semi-arid environments, prone to long dry summer seasons and especially vulnerable to drought.
- Population growth outstripping water supply.
- Desire for trees near homes for shade and rural atmosphere as “escape” from the city.

- Implications for the forecaster:

- Recognition of dangerous fire weather conditions is relatively easy.
- Prediction of in-fire weather conditions is VERY difficult.
- Scale of the wind phenomena usually smaller than observations or numerical models.  Special mesoscale models now exist that integrate fires into models: e.g., Terry Clark, NCAR).

- Urban Flooding

**WILDFIRE**

**Notes:**
**Deaths during heat wave in Chicago: 465-739

## TWC has large interest in this area.

**IN CLOSING....**

- 70% of TWC viewing households are in urban environments.