Archive for December 16th, 2012
Rain is ending from west to east across Central Alabama. The backside of the rain shield is roughly a line from Gadsden to Anniston, through Talladega, Clanton and near Marion. The rain will continue to taper off over the next couple of hours. More development of showers and thunderstorms is expected during the early morning hours when more dynamic forcing will be interacting with the moist atmosphere. Some of these storms could be strong and some isolated severe weather is still possible through mid-morning tomorrow.
As the rain tapers off across the area winds will increase briefly. Expect some gusty winds for 15-30 minutes on the back side of the rain shield. A gravity wave feature is working across North Central Alabama. Winds will be gusting 20-30 mph. No severe winds but much of Central Alabama is under a significant weather advisory for the gusty winds until 10 PM Central Time.
Looking at this overall event. Much of north Central Alabama continues to remain in stable air as rain has been falling most of today. Rain is beginning to taper off in our northwestern counties and should begin to taper off in Central Alabama. Rain and thunderstorms will redevelop and become widespread again during the early morning hours.
Looking at the simulated radar for in the morning, rain and thunderstorms will be over much of Central Alabama. Some of the heavier storms look as though they could be off in some of northwestern counties. Could be a messy commute in the morning. Storms should be strong and once again these storms could reach severe limits. Some heavier activity will also be off to our southwest along the Highway 80 corridor. The storms will be moving to the east through the morning and should be exiting Alabama by early afternoon .
Many areas to the south and west of the Birmingham metro continue to be under a slight risk for severe weather. The current risk is valid until 6 AM Central Time. Upper level forcing dynamics will be moving in across the state tonight. Still think there is a good chance of some severe weather overnight and into tomorrow morning. As the better dynamics move through, strong storms will be possible in our area, with some storms possibly being severe. The more widespread severe weather threat will be across our southern counties. Main threat will still be damaging winds and the chance for some isolated tornadoes. Flooding will continue to be a threat as well. Some isolated tornadoes are still possible within the risk area. You do not have to be in a risk to have severe weather. Any location in or near this risk should keep a careful eye on the weather during the overnight hours.
Let’s try and answer your questions concerning Alabama’s weather tonight and tomorrow.
RIGHT NOW: A large rain mass is over North and Central Alabama. The air is cool and stable for now, and there is no severe weather. I don’t expect any through the evening hours.
Many churches have Christmas music programs tonight; severe weather won’t be a problem, but needless to say the weather will be wet.
SEVERE WEATHER LATE TONIGHT? SPC maintains their standard “slight risk” of severe weather for roughly the southern half of Alabama… south of a line from Livingston to Clanton to Rockford. The primary risk comes after midnight when better dynamic forcing comes into play.
We note there is a low end tornado risk, mainly over Southwest Alabama…
Below is the projected radar reflectivity at 4:00 a.m. tomorrow (from the 4km NAM)
And, tomorrow’s convective outlook…
HEAVY RAIN POTENTIAL: Sure looks like storm totals will exceed two inches around here… below is the projected rain through 60 hours…
I don’t think flash flooding will be a major concern since the ground isn’t saturated, but something to watch.
BOTTOM LINE: A marginal severe weather threat is ahead late tonight and tomorrow morning, mainly for the southern half of Alabama, south of a line from Livingston to Clanton to Roanoke. While an isolated severe storm is possible over North Alabama, the air will be pretty stable there.
An MCS (mesoscale convective system) type feature will likely move across South Alabama after 2:00 a.m., continuing into early Monday morning. There will be sufficient instability and shear for a few severe storms. The main threat will be from damaging winds, although an isolated tornado can’t be ruled out. Be sure your NOAA Weather Radio, or smart phone app you use for warnings, is in proper working order in case some warnings are needed after midnight or early tomorrow.
AND… Another system would bring a severe weather threat to Alabama Wednesday night into Thursday; more about that one tomorrow morning.
NOTE: I get hundreds of questions on social media… mainly about weather for a specific neighborhood, town, or county. Most of the weather threats here in our state are broad and impact a large area; if you take the time to read this discussion (THANK YOU for doing it), then you can see if you are in a risk area. Time doesn’t allow us to go through every small town and neighborhood.
We will have running updates on the blog tonight as the weather unfolds…
THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED AN
* URBAN AND SMALL STREAM FLOOD ADVISORY FOR MINOR FLOODING OF POOR
DRAINAGE AREAS IN…
SOUTHEASTERN AUTAUGA COUNTY IN ALABAMA…
THIS INCLUDES THE CITY OF PRATTVILLE…
SOUTHWESTERN ELMORE COUNTY IN EAST CENTRAL ALABAMA…
THIS INCLUDES THE CITY OF MILLBROOK…
* UNTIL 600 PM CST
* AT 301 PM CST HEAVY RAINFALL WAS FALLING ACROSS PORTIONS OF
SOUTHEASTERN AUTAUGA AND SOUTHWESTERN ELMORE COUNTIES. ONE TO TWO
INCHES OF RAINFALL HAVE OCCURRED AND ADDITIONAL RAINFALL IS
EXPECTED. THIS MAY CREATE MINOR FLOODING IN POOR DRAINAGE AREAS.
MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE…TURN AROUND…DONT DROWN.
A FLOOD ADVISORY MEANS RIVER OR STREAM FLOWS ARE ELEVATED OR PONDING
OF WATER IN URBAN OR OTHER AREAS IS OCCURRING OR IS IMMINENT.
A nice steady rain continues to fall across much of North Central Alabama. Heaviest rain continues to fall from a line near Demopolis to Heflin. Additional showers and thunderstorms are expected to develop along the cold front back off to our west and will be impacting Alabama overnight.
The severe weather threat has lessened across much of North Central Alabama. The latest outlook has trimmed Birmingham and Tuscaloosa out of the risk, but Demopolis, Clanton, Montgomery, Greenville and Mobile remain in it. The rain over our part of the state has help to stabilize the atmosphere. Further south, it hasn’t rained as much and the atmosphere is still unstable. We still expect severe weather across Alabama tonight, as the main upper-level dynamics work through the state. Widespread severe weather is still expected to develop in Louisiana and Mississippi and move towards Alabama.