Sunday, February 3, is forecast to be Code Orange for particulate concentrations in Delaware!
Particle concentrations rose much faster than expected on Saturday morning, due to an extremely strong surface inversion enhanced by Friday’s snowfall. As of 2 PM Saturday, hourly particle concentrations are dropping in response to increasing surface winds and a break in the strong temperature inversion at the surface. Daily average particle concentrations will end up in the upper Moderate for Saturday, however, which is much higher than normal for this time of year. **Sunday’s Forecast: Sunday’s weather conditions are expected to be extremely stagnant. Surface winds will be calm all day. Another very strong morning surface inversion will form, but the difference from Saturday is that this inversion is not forecasted to break in the afternoon. As a result, atmospheric mixing will be minimal for the entire day. Given how quickly particles rose on Saturday, in conjunction with the very stagnant forecast, particle concentrations will reach the Code Orange (Unhealthy for Sensitive Groups) range on Sunday.
A Code Orange air quality forecast for ozone is a level of pollution that can be unhealthy for sensitive groups, such as young children, the elderly, and those with heart and/or respiratory conditions. Such persons should limit outdoor activities, especially those that require a high level of exertion. Any health related questions should be directed to the Division of Public Health at 302-739-6619. All other questions should be directed to the Division of Air Quality at 302-739-9402.