Smoke hanging over Moose Jaw is expected to gradually improve over the next day, but another round of wildfire smoke could arrive later this week as winds shift. Environment Canada meteorologist Janelle Gergely said the smoke affecting southern Saskatchewan earlier this week originated from wildfires burning in Saskatchewan and the Northwest Territories. "A lot of the smoke that was coming in, it came from fires across northern Saskatchewan and even as far north as the Northwest Territories as those upper-level winds were bringing a northerly flow affecting that smoke southward." Gergely said fresh smoke is not expected to move into the region Wednesday, but lingering smoke could take time to clear because of light winds. She added forecast models show upper-level winds shifting later this week, potentially bringing smoke from British Columbia into southern Saskatchewan. "Smoke from the fires in the interior B.C. could start infecting the Rockies and moving into southern Saskatchewan as early as Thursday evening or Friday." Smoke concentrations remain difficult to predict While forecast models can predict where smoke is likely to travel, Gergely said it's much harder to determine how much will reach ground level. Smoke can remain high in the atmosphere without affecting air quality at the surface. "Our smoke models, they do a fairly good job of telling us where that plume of smoke is going to be, but it struggles with concentrations as well as how it's going to impact the surface." She noted Moose Jaw was experiencing moderate Air Quality Health Index values Tuesday because of fine particulate matter, known as PM2.5, suspended in the air. Related Stories: Fatal crashes up 77 per cent as RCMP urges drivers to make safe choices Saskatchewan sees above-average tornado activity this July Heat wave expected to push Moose Jaw temperatures into the mid-30s Saskatchewan Premier says Canada has to get to the negotiating table to get ahead of tariffs ▶️ Stream this news story: 800 CHAB, Country 100, Mix 103 Monitoring air quality Environment Canada issues an air quality alert when the Air Quality Health Index reaches a value of seven or higher for several hours. Gergely said poor air quality isn't always easy to detect by sight or smell. "Our nose and our eyes aren't always the greatest indicator of how poor the air quality is. It's really these sensors that are the best indicators." Air quality is monitored using sensors that continuously measure PM2.5 — tiny smoke particles that can affect human health. The readings are updated every 10 minutes at monitoring stations across Saskatchewan. Limiting smoke exposure Gergely said most people can continue their normal activities when air quality values are in the moderate range, but they should pay attention to symptoms such as irritated eyes or a sore throat. She recommends limiting time outdoors if smoke levels increase, wearing an N95 mask when necessary, running a HEPA air filter, and keeping windows closed to reduce smoke entering homes. However, she acknowledged the current stretch of hot weather makes that advice more difficult to follow. "When it's smoky, you want to close your windows. But of course, when it's warm in the evening hours, you may want to open your windows to let in that cooler air. So of course, there are complications when these two events are happening at the same time."