You can tell summer is here; yesterday was one of the first “Code Orange” air quality alert days of the season for the Birmingham metro and is in effect today as well. That means air quality is expected to be “unhealthy for sensitive groups” of people, like those with asthma. Ground level ozone is the culprit, and is an issue on many hot summer days in Birmingham.

Ozone is a gas composed of three atoms of oxygen. Ozone occurs both in the Earth's upper atmosphere and at ground level. Ozone can be good or bad, depending on where it is found:

*Good Ozone. Ozone occurs naturally in the Earth's upper atmosphere-6 to 30 miles above the Earth's surface-where it forms a protective layer that shields us from the sun's harmful ultraviolet rays. This beneficial ozone is gradually being destroyed by manmade chemicals. An area where the protective "ozone layer" has been significantly depleted-for example, over the North or South pole-is sometimes called "the ozone hole."

*Bad Ozone. In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone at ground level is a harmful air pollutant. This ground level ozone can irritate your respiratory system, reduce lung function, aggravate asthma, and inflate and damage cells that line your lungs. Your chances of being affected by ozone increase the longer you are active outdoors and the more strenuous the activity you engage in.

We will always let you know when air quality alerts are in effect!

Since the weather is quiet around here, thought I would share another viewer picture... this one is a sunset over Lake Lanier in Georgia. The picture was taken this past Saturday night by Diana Butler...

The Thursday afternoon map discussion is available on the web, and on iTunes:

http://www.jamesspann.com/

There is an old saying in our business... you don't forecast rain in the middle of a drought. Some validity to that saying, so I guess we shouldn't get our hopes up for a big rain event anytime soon.

TOMORROW: Should be another sunny and hot day with highs between 90 and 95.

THE WEEKEND: A nice upper trough moves into Texas, and should bring some beneficial rain to parts of Texas, Oklahoma, Arkansas, and Louisiana. They really need the rain as well; places like Shreveport, Tulsa, and Dallas should see some pretty decent rain. The trough will become nearly stationary over Texas, which means the best chance of afternoon showers and storms should be over the western part of Alabama on Saturday and Sunday. East of I-65, afternoon showers will probably be pretty scarce. Highs will be in the 87 to 91 degree range, but humidity values over the weekend will be higher.

NEXT WEEK: A weak surface boundary will slowly approach from the north, and we will continue to mention a chance of scattered afternoon showers and storms Monday through Thursday. The GFS suggests the best shot at a shower here could come on Tuesday and Wednesday. But, we stress that all afternoon showers will be scattered, meaning rainfall distribution won't be even, and some spots will miss getting the rain. That is the nature of afternoon showers and storms on a summer day in Alabama.

OZONE ALERT: Today's AQI (air quality index) in the Birmingham metro area is 83, which is considered moderate. Another code orange air quality alert has been issued for tomorrow, meaning air quality should be unhealthy for "sensitive groups". Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.

SKYWATCHERS: We continue to build a large team of volunteer Skywatchers across Alabama. Members of this team will report weather conditions to us in real time using Instant Messaging. We are looking for people who have been trained in severe weather spotting, and want to learn more about weather. Our greatest needs are in rural areas, where surface reports are hard to come by. But, we can use eyes anywhere. These Skywatchers will also be sending us digital photos and video of weather. Interested? Send me an e-mail and tell me about yourself: jspann@abc3340.com

The next map discussion video will be available by 7:00 a.m. tomorrow!

Thanks to Vic Bell, our online weather watcher in Black Creek (northeast of Gadsden) for this shot taken earlier this morning:



See J.B.'s note below for temperature information. The Anniston Airport thermometer is dead wrong; it was too cool all day yesterday as well. Hopefully someone will get it repaired soon!

I have already been out walking early this morning and it is very pleasant...59 degrees at my place in NE TRussville. Some temperature inversions also. Examples:

68 at the Skycam location on Mt. Cheaha. 16 degrees lower at Anniston Airport with 52. (It appears that the Anniston Airport temperature may be a few degrees too low)

In NE Alabama, 70 up on the ridge overlooking Gadsden at the Skycam site, but 59 at Gadsden Airport. 63 in Albertville on Sand Mountain, but 55 in Fort payne down in the valley.

Enough of that...here are some 6 am temperatures to enjoy. These may or may not be the final low of the morning:

55 in Cullman, Gadsden, Fort Payne
56 in Crossville
61 in Decatur
63 in Tuscaloosa, Albertville
66 in Montgomery, Calera

Tis possible that Tuscaloosa could see a 32-degree jump in temperatrure, possibly reaching 95 this afternoon.

Patiently awaiting Mr. October...

The Thursday morning map discussion video is on the server, and available on iTunes:

http://www.jamesspann.com/

I guess in the weather business we always watch developments to the west. And, in the summer, you better see what is going on in all other directions as well.

But, a strong upper trough will be digging down through the Rockies today, and ultimately into Texas and Oklahoma over the weekend. Large scale ascent will increase east of the trough axis, and a pretty good rain event is shaping up over the next two days for parts of Texas, Oklahoma, Arkansas, and Louisiana. Like us, they really need the rain and it is a good thing.

WHAT ABOUT US? We stay hot and dry today and tomorrow; lots of sun with highs in the 90 to 94 degree range for most spots. The upper trough will sit over Texas and slowly weaken over the weekend and into early next week, but it seems as though it might bring a fairly decent chance of scattered (mainly afternoon and evening) showers and storms to the western half of the state Saturday and Sunday. If you live along and west of U.S. 43 (west of a line from Florence to Tuscaloosa to Demopolis), the chance of getting wet over the weekend is about one in three. But, if you live in east Alabama, that chance drops to about one in eight.

Afternoon highs actually might back off a bit over the weekend due to scattered showers and cloudy periods, but on the other hand dewpoints will be going up, so humidity levels will be higher.

NEXT WEEK: We will still mention a chance of afteroon showers and storms in scattered spots Monday through Wednesday as the upper feature remains to the west, and a weak surface front approaches from the north.

Bottom line is that there is a CHANCE your front yard will get a shower or storm on a daily basis Saturday through Wednesday. But remember, just a chance. The scattered nature of afternoon showers in the summer can be very frustrating during the times like this when we really need rain on a widespread basis.

ALSO... remember that many water systems are running low, and if your water system administration is asking for water conservation, please follow their guidelines when it comes to watering the lawn, washing the car, etc.

TOPIC: TROPICS: The storm formerly known as Alberto is racing northeast away from the U.S. mainland now. The wave over the Caribbean has fizzled out, and another wave is in the central Atlantic moving to the west. Waves in that region rarely develop this early in the season, and tropical mischief doesn't look likely over the next week or so.

The next map discussion video will be posted by 3:30 this afternoon!