The Alabama Climate Report

Brought to you by the Office of the Alabama
Climatologist

Volume 7, Number 11 - August 2017

It feels like it was a mild summer, but something interesting was happening while most of us were asleep: Temperatures weren't dropping as much as they usually do, keeping average summer temps warmer than we might have realized.

This wasn't unique for Alabama. In a recent conference call with other state climatologists around the south, we were all talking about our warmer than normal nights this summer.

How warm?

According to data from the Southeastern Regional Climate Center (SERCC), daily lows in Mobile, Birmingham and Huntsville were all in the top 14 warmest summers; Montgomery's summer lows were the 4th warmest on record (which goes back to 1948).

By comparison, high temperatures in all four cities were cooler than normal for June, July and August. How cool? Alabama had only two 100° days reported this summer (both in Andalusia/Opp in July). There were only five 99° reports this summer.

The SERCC data also says the past 12 and 24 month periods were the warmest September through August periods on record, which means something was going on before May, when our 21-cities sample says the state's average temperature dropped below the monthly norms.

A look at our sample over the past 12 months shows eight warmer than normal months followed by a cool May and summer. How warm? September 2016 averaged more than 3° warmer than normal, and October more than four. January was 8.3° warmer and February more than 7° warmer than normal.

Winter months tend to have larger swings in temperature than summer months, but we might not notice those as much when winter temps are relatively comfortable and warm. But those warm winter months add into the yearly average, in this case enough to offset a relatively mild summer and give us those record September-through-August warm temperatures.

We should also note both the end of the continental U.S. major hurricane drought, with the landfall of Hurricane Harvey, and the presence now of Hurricane Irma. The remnants of Harvey were strong enough to bring significant rain to Alabama, and to spin up three tornadoes, including an EF-2 that hit Reform and injured six people.

Alabama isn't in the most recent forecast bulls eye for Irma, but we are close enough to start feeling uncomfortable. With its record-breaking sustained winds, Irma won't need to make a direct hit on Alabama to cause extensive damage. Not to sound like a broken record (or CD), but it isn't nearly too early to be making severe weather preparations ... just in case.

Keep an eye on the weather and be safe.

- John Christy