PA Ozone/PM2.5 Forecast
March 3, 2015
Date: Tuesday, March 3, 2015
A multi-day stretch of wintery precipitation will impact the Philadelphia metropolitan area Tuesday-Thursday. It will be clear on Tuesday morning as surface high pressure moves overhead. But snow and sleet will overspread the area from west to east starting early Tuesday afternoon before turning to all rain in the evening. A brief surge of cold and dry air overnight will help to inhibit particle formation. The arrival of much warmer air aloft in the afternoon and steadily rising humidity will act to increase particle concentrations later in the day, with overall daily average air quality in the mid-Moderate range.
Rain will continue overnight and through the day on Wednesday as a slow-moving cold front makes its way across the Mid-Atlantic region. Light southerly flow and continued high atmospheric humidity will allow particles to rise higher into the Moderate range. The cold front will stall across the Mid-Atlantic on Thursday, and a wave of low pressure will ride along the front, bringing periods of heavy rain to Philadelphia. As cold air filters in behind the front, the rain will change to snow, with several inches of accumulation possible. Breezy winds and heavy precipitation will clean out the atmosphere and drop particle concentrations to the Good range.
Go to the new Air Quality Partnership of the Delaware Valley web site!