What is a Signficant Weather Advisory?

What is a Significant Weather Advisory?

Thunderstorms are very common here in central Alabama. There are multiple times during the year when different weather patterns affect us in different ways. In the Spring, we have our primary severe weather season during the months of March, April and May. In the Fall, we experience our secondary severe weather season during the months of November and early December.

It's during these two seasons when synoptically driven weather usually affects us, giving us derechos, squall lines and the occasional supercell thunderstorm.

During the Summer months, when central Alabama is typically under the influence of high pressure, thunderstorms usually form for reasons other than frontal forcing, such as outflow boundaries, sea breezes, or simply the heating of the afternoon.

Whatever the reason may be for thunderstorm formation, in order for a thunderstorm to be considered severe, it must create at least one of the following:

Hail that is one (1) inch in diameter or larger

Winds of 58 miles per hour (mph) or greater

If it doesn't meet those criteria, that doesn't mean that the storm needs to be discounted. Many storms that form in central Alabama do not meet Severe Thunderstorm criteria. When they don't, we might issue a Significant Weather Advisory.

Significant Weather Advisories

Issued under the product name Special Weather Statement (SPS), a Significant Weather Advisory is issued to keep the public and media abreast of weather situations that are significant, but not thought to be life-threatening.

Such situations might include (but are not limited to), excessive lightning, wind potential less than 58 mph, hail stones smaller than one (1) inch in diameter or even locally heavy rainfall.

Other Important Information

Like our Severe Thunderstorm Warnings, Significant Weather Advisories are issued normally for 30-60 minutes at a time. Each advisory will be transmitted on NOAA Weather Radio, but will NOT alert your radio. You can also follow the advisories from the front page on our website.

IIt is important that the public is aware of this information, but equally as important is the reporting of hail or any type of wind damage. If you witness any size hail falling to the ground or any type of damage caused by wind in Central Alabama, report it through Social Media using the hashtag (#)alwx or #bmxwx, let us know on our Facebook Wall, or give us a call at 205-664-3010, and select 2 to speak to a forecaster.