The following weather and atmosphere-related links have been recommended to me by meteorologists with years of experience. Check them often, but, most importantly, pay attention to your local weather starting three days before the eclipse. Scroll down for Traffic Links.
1. The National Weather Service's Eclipse Weather Page
2. Skippy Sky (recommended by Jay Anderson)
3. Clear Outside (another favorite of Jay Anderson)
4. The Weather Channel — Be sure to check your local forecast often.
5. Intellicast — another site to check more and more as the eclipse approaches.
6. The NOAA Single-image Fire View
7. Wildfire Today's Smoke Map
T1. Safe Travel USA (Clicking on a state will bring up its highway department website, many of which have a link to roadside webcams.)