Saturday, May 24, 2008:
Ozone (O3) – Code GREEN
Fine Particulates (PM 2.5) – Code GREEN
Sunday, May 25, 2008:
Ozone (O3) – Code YELLOW
Fine Particulates (PM 2.5) – Code YELLOW
Monday, May 26, 2008: *** Memorial Day Holiday ***
Ozone (O3) – Code YELLOW
Fine Particulates (PM 2.5) – Code YELLOW
Tuesday, May 27, 2008:
Ozone (O3) – Code GREEN
Fine Particulates (PM 2.5) – Code YELLOW
Regional Maximum PM 2.5 Concentrations:
Thursday, May 22, 2008:
Ozone - GREEN (19 AQI or 23 ppb)
PM 2.5 – GREEN (29 AQI or 8.9 µg/m3)
Short-Term Discussion: Pleasant weather is expected for the remainder of the afternoon though we will begin to transition to warmer more seasonal temperatures in the next day or so. While the weather should be quite nice over the Memorial Day weekend, air-quality levels will begin to deteriorate as warm stagnant conditions briefly set up before a cool front slowly crosses the state on Tuesday. Ozone concentrations will probably peak on Monday while fine-particulate concentrations are expected to on Tuesday. We will not issue an Air-Quality Action! alert for the Lehigh Valley/Berks forecast area due to frontal-passage uncertainty later in the forecast period. This, however, does not mean that Monday’s ozone concentrations and Tuesday’s fine-particulate concentrations will not push beyond the upper moderate threshold.
Mainly clear overnight and chilly once again with temperatures expected to fall into the upper 40s. Becoming mostly sunny and pleasant with afternoon temperatures expected to be in the low 70s. Northerly winds and dry air should keep Saturday’s ozone and fine-particulate concentrations in the upper code GREEN (good) range.
Mainly clear overnight with temperatures expected to fall into the mid 40s. Mostly sunny and a bit warmer on Sunday with temperatures rising into the upper 70s. Winds will switch to the southwest late in the day bringing more humid air into the region. Sunday’s ozone and fine-particulate levels are both expected to work their way into the code YELLOW(moderate) range.
Mainly clear overnight with some patchy fog possible by sunrise and temperatures expected to fall into the low 50s. Mostly sunny early with increasing clouds expected later in the afternoon. There is an outside chance of a shower or late afternoon thunderstorm, especially to our north. Temperatures on Memorial Day could reach 80 degrees. We expect Monday’s ozone concentrations to push into the upper code YELLOW (moderate) range. Fine-particulate concentrations are also expected to reach the code YELLOW(moderate) range.
Cloudy with showers and possibly a thunderstorm overnight; low temperatures will be in the 60s. Mostly cloudy with showers and possibly thunderstorms on Tuesday as a cool front slowly crosses the region. Afternoon temperatures will probably be in the 70s. Clouds and showers should keep Tuesday’s ozone concentrations in the code GREEN (good) range while high humidity levels and relatively dirty air ahead of the cool front will allow fine-particulate concentrations to remain in the code YELLOW (moderate) range.
Extended: Our brief bout with warm and humid air should come to a close after Tuesday. We expect pleasant seasonal weather for the middle of next week as a ridge of high pressure builds over the forecast area. With light northerly winds, drier air and near normal temperatures, air-quality readings should fall in the good to moderate range for the extended period.
Tags: air quality forecast, AQI, AQP
