| After the cold front last weekend, bright
sunshine in a dry atmosphere led to an increase in ozone and its
precursors. A strong low-pressure
system will develop on the Canadian prairies today and induce southerly wind,
but the hurricane in the Gulf of Mexico will induce northerly wind to cancel
those southerlies and leave Oklahoma with light and variable winds. This stagnation will contribute to
unhealthy ozone for sensitive groups in and near Oklahoma City and Tulsa and
moderate air quality away from the urban areas. Prescribed and agricultural fires will
contribute to the problem and may cause locally unhealthy smoke. After the hurricane makes landfall and
weakens, the southerly flow will predominate and bring pollution northward
from Texas tomorrow; therefore, ozone will reach near or above the top of the
moderate category across a swath of central Oklahoma. Meanwhile, another tropical storm will
approach California on Sunday and enhance the southerly flow, which
ultimately will bring an increase in humidity and clean air from the Gulf of
Mexico in time for Columbus Day. The
summerlike warmth will continue until another Pacific tropical system may
lead to rainfall toward the end of next week. |