Steve Caparotta WAFB

Check this out!

A beautiful 22-degree solar halo was spotted today over the Youngsville Sports Complex, captured by John Lewis.

These halos form when sunlight passes through millions of tiny ice crystals suspended within the thin cirrus clouds seen in this pic. As the light is refracted, it bends at a specific angle, creating the bright ring around the sun.

The 'normal' high reaches 90° in Baton Rouge on Thursday & doesn't drop below 90° until Sept. 13. Thoughts? 😏

⚠️ FLOOD ADVISORY

A Flood Advisory has been posted for portions of West Baton Rouge and Iberville parishes through 6:15 PM. Very heavy rain extends from around Erwinville through Rosedale, Grosse Tete, and Ramah. Watch out for flooded roads!

What happened in Zachary Tuesday night? Several of you submitted pictures and videos of flooding, including the video below at Groom Road and Plaza Drive from Tami Dugas. The immediate assumption is that there must be a drainage problem.

I can't tell you with any confidence if there are drainage issues or not, but what I can tell you is that RAIN RATES were intense and likely to produce at least some flash flooding. The USGS has a gauge on White Bayou at Highway 64. Note in the second graphic below that 1.84" of rain fell in 30 minutes, and more than 2 inches fell in 45 minutes. The third graphic shows 15-minute accumulations, and with nearly an inch in 15 minutes around 7 PM, that equates to a rain rate of ~4 inches per hour.

Finally, in the last graphic, notice that flash flood guidance from the National Weather Service leading into last night's event suggested that 1-hour rains of 2.75"-3.00" would be enough to lead to flash flooding. This rain gauge was close and others may have achieved those values. Either way, it's close enough. We have to also account for a very wet May when considering flash flood risk.

The takeaway -- flooding is complicated and there are often multiple variables in play.