BORTAS A (2010)
BORTAS Meteorological and Air Quality Forecast for Halifax region (Boundary
Layer and Free Troposphere)
Issued: Tuesday, August 10, 2010 AM/PM: AM
Issued by: David Waugh
Valid Today , Tonight and Wednesday with an outlook for Thursday
Quick overview: Moderate potential influence from boreal biomass today, High tonight then tapering off Wednesday.
Low potential LRT of anthropogenic aerosols.
Synopsis/Synoptic Discussion:
The NRCan Hotspots map shows a considerable number of fires over northwest
Manitoba -northeast Saskatchewan extending to Great Slave Lake. Isolated fires in southern Yukon, BC, and southern Manitoba.
Blocking pattern over North America with upper low over northern Labrador, a mid continent ridge southward from Nunavut and a trough over BC. Very slow eastward drift of these expected for next 48 hours as upper trough sharpens over
Newfoundland. 500 hPa flow pattern suggests smoke from northern Prairies will drift northward over Nunavut then stream southeastward across Quebec to the Maritimes in strengthening upper flow on the west side of the sharpening upper trough.
Generally light southwesterly surface flow continues with bands of mid cloud forecast to rotate around Labrador low today and tonight. Weak cold front crosses NS tonight with northerly surface flow in its wake for Wednesday and Thursday.
GEOS-5 run commencing 10 th 00UTC has low to moderate CO values below ~7 km today then a strong impulse overnight, particularly below ~3km then tapering off late
Wednesday.
GEM-MACH shows weak plume of anthropogenic aerosols in west-east line just south of Halifax this morning with little movement today but then pushing southeastward
Wednesday.
Today:
Clearing to become a mix of sun and cloud later this morning. Fog retreating to the coast. Moderate levels of boreal biomass CO below ~7 km. Low potential for LRT of anthropogenic aerosols.
Tonight:
Cloudy periods with chance of an overnight shower and risk of a thundershower.
Moderate levels of boreal biomass CO below ~7km but increasing to high CO overnight below ~4 km. No significant LRT of anthropogenic aerosols.
Wednesday:
Sunny with cloudy periods and slight chance of an afternoon or early evening shower.
Moderate to high potential boreal biomass CO in the morning below ~ 6 km then tapering off later in the day. No significant LRT of anthropogenic aerosols.

Outlook for Thursday: . Sunny. Low - Moderate potential for boreal biomass CO. No significant LRT of anthropogenic aerosols.
Contact: David Waugh Contact number: 426-9136