Urgent Dense Fog Advisory: How Today’s Near-Zero Visibility Could Disrupt Your Morning Commute

Early commuters in several corners of the country are waking up to a National Weather Service (NWS) dense fog advisory that could make the Tuesday-morning drive treacherous. Where the advisory is active • Central Alabama – Jefferson, Shelby, Talladega, Clay and Randolph counties until 9 a.m. CST • Southwest Washington – Olympia, Southern Puget Sound, Lewis and Thurston lowlands and the Middle Chehalis River Valley until 9 a.m. PST • Additional patchy dense fog is being reported across parts of the Upper Midwest and Gulf Coast, and local offices may expand advisories as visibility drops below a quarter-mile. What to expect Visibilities could fall to 200 ft (60 m) at times, creating “pea-soup” conditions on interstates, rural highways and airport runways. Temperatures hovering near the dew point will allow the fog to thicken through sunrise before gradual improvement by late morning. Travel impacts • Driving: Reduced visibility, slick spots on bridges and overpasses. • Aviation: Possible departure delays at Birmingham-Shuttlesworth, Seattle–Tacoma and regional airports. • School buses: Districts in affected counties advise parents to expect slower routes. Safety tips from NWS forecasters 1. Slow down and switch to low-beam headlights; high beams reflect off water droplets and cut your sight distance. 2. Leave extra following distance and watch lane markers to stay oriented. 3. If visibility hits zero, pull into a safe parking area; if that’s impossible, move well onto the shoulder, keep hazard lights on and foot off the brake pedal so tail lamps aren’t lit. When will the fog lift? Radiational cooling, clear skies and light winds helped the fog form overnight. As solar heating mixes the lower atmosphere, visibilities should improve between 9 a.m. and 10 a.m. local time. However, valleys and low-lying areas may see lingering pockets through midday. Looking ahead A weak cold front sliding through the Southeast tonight and strengthening onshore flow in the Pacific Northwest tomorrow will increase low-level mixing, limiting another round of widespread dense fog on Wednesday. Motorists are still urged to monitor the latest forecasts in case new advisories are issued.