BORTAS A (2010) BORTAS Meteorological and Air Quality Forecast for Halifax region (Boundary Layer and Free Troposphere) Issued: Tuesday, July 20, 2010 Issued by: Doug Steeves AM/PM : AM Valid Today, Tonight and Wednesday with an outlook for Thursday Quick overview: Low Potential influence from biomass burning aerosols through the period. Low Potential influence from LRT anthropogenic through period. Synopsis/Synoptic Discussion: Northern Saskatchewan and northwestern Manitoba continue to be the area of interest for biomass burning. However the upper flow in that region remains light which is not conducive to long range transport. US Smoke model shows no smoke over Atlantic Canada through period. There has been little change in the weather pattern with a large low over Labrador both at the surface and aloft. A zonal flow persists across southern Canada and northern US. This pattern will break down Wednesday night as an upper low forms in a sharp trough over Montreal then moves over the Maritimes by Thursday. GEM-MACH is showing a bogus area of high anthropogenic aerosols greater than 35 ug/m3 over much of mainland Nova Scotia this morning. This is not substantiated by the monitoring network. Otherwise the main anthropogenic plume remains south of the Maritimes. Today: Cloudy with sunny periods. No significant aerosols. Tonight: Cloudy periods. No significant aerosols. Wednesday: Sunny with cloudy periods. A slight chance of showers in the afternoon. No significant aerosols. Outlook for Thursday: Periods of rain. Low potential for anthropogenic aerosols. Low potential for biomass aerosols. Contact: Doug Steeves Contact number: 426-1717