Indiana may see above-average winter precipitation

This week's rain got you down?

Thursday's nearly constant drizzle in Indianapolis brought less than 1 inch of rainfall. Paired with a slight breeze and highs in the mid-50s, it was a dreary day.

But a light drizzle might be the least of our worries, especially as we head into the winter months.

With fall in full swing, the National Oceanic and Atmospheric Administration released its U.S. Winter Outlook on Thursday, showing chances for a wetter-than-normal Indiana winter from December through February.

Conditions in the outlook are affected by La Niña, an ocean-atmosphere climate interaction that occurs in the Pacific Ocean and cools sea surface temperatures, leaving the South warm and dry and the North cool and wet, according to NOAA.

Indiana and much of the Great Lakes region have a 33 percent chance of higher-than-usual precipitation this winter.

But that doesn't mean snowfall will be higher than normal, said National Weather Service meteorologist Michael Koch. Some of that precipitation could be rain — it all depends on when it moves in and what the air temperature is.

"It’s just about timing," he said.

NOAA determines that 33 percent by looking at indicators of above-, below- or normal precipitation and assigns areas to one of the three precipitation levels, Koch said. Because it fits one of the three categories, NOAA assigns a 33 percent chance.

In other words, don't start buying the canned goods yet.

“It’s really hard to correlate,” he said. “Just because it’s above-normal precipitation expected, does that mean we’re above-normal snow? I’m guessing more times than not it would be, but you don’t really know that for sure.”

Indiana typically sees its highest precipitation levels in December, with average totals of just over 3 inches, compared with the 2 inches that usually fall in January and February, according to NOAA. Indiana records its highest snowfall totals in January, with an average of 8.6 inches.

Indiana isn't the only region affected by La Niña. Conditions are expected to be drier than normal in the southern half of the U.S. this winter, so if you're a snowbird who spends the winter months in sunnier places, such as Texas or Florida, expect a dry winter. The southern half of the U.S. has a 50 percent chance of drier-than-normal conditions.

While dry conditions in the South typically accompany higher-than-normal temperatures, as expected across much of that region this winter, the possible increase in precipitation in Indiana doesn't necessarily mean the state will be warmer or cooler than usual.

With respect to temperature, Indiana falls into a category labeled "equal chances," meaning there's not yet a strong signal that anything drastic will happen. Indiana is equally likely to experience below-, above-, or normal temperatures this winter.

Indiana is typically at its coldest in January, with average high temperatures of 36 degrees and lows in the high teens and low 20s, according to NOAA.

Don't worry. There's plenty of time yet before winter arrives: NOAA says the average date of Indiana's first measurable snowfall is Nov. 19.

Predictability with a 33 percent chance doesn't give a strong indication of any significant weather event, Koch said. But don't dismiss the outlook entirely.

"I wouldn’t panic," Koch said. "And, on the other side, I wouldn’t say: 'Oh shoot, we’re not going to get any snow this year.'"

As for this week, skies are clearing up: Chances of rain will disappear from the forecast by Friday morning, with sun expected all weekend and into next week. Highs for Friday and Saturday are expected to reach the mid- to high 50s, with Sunday's high nearing 68 degrees. Lows are expected to remain in the 40s.

Call IndyStar reporter Holly Hays at (317) 444-6156. Follow her on Twitter: @hollyvhays.