Marathon runners to face humid conditions

Later Sunday, storms could cause flooding.

If you’re running in this year’s 26th annual Austin Marathon on Sunday, be prepared to see some rain.

Friday and Saturday are expected to be mostly sunny with high temperatures in the upper 70s and mid-80s, according to the National Weather Service. Normally, daytime highs for this time of year are at least 10 degrees cooler.

Lows for Friday and Saturday will be in the upper 40s and lower to mid-50s, which is closer to the seasonal norm.

Early Sunday morning, moisture will likely be moving into Texas from the Gulf of Mexico, which means light showers will be possible around the start of the marathon. For the duration of the 26.2mile race, forecasters expect winds of 5 to 10 mph with humidity levels as high as 80 to 90 percent.

By Sunday afternoon and evening, the light showers will turn into storms that could produce 2 to 4 inches of rain. However, meteorologists say it’s possible the rainfall could total up to 5 to 6 inches to the east of Interstate 35 and possibly cause some isolated flooding Sunday evening into Monday morning.

No severe weather such as hail or tornadoes is expected, only heavy rains and possible storms with lightning. Meteorologists with the weather service said they are closely monitoring conditions and will alert people in the Austin area if more severe flooding or storms appear in the forecast.