The meteorological authority | Potential for severe to severe storms

On the ABC 33/40 weather blog:

TODAY & # 39; HUI

The meteorological authority | Potential for severe to severe storms

We are ready to face strong to strong storms on the northwestern quarter of north / central Alabama throughout the afternoons, night and night tonight. The Storm Prediction Center has an increased risk of severe storms for locations west of a line ranging from Millport to Phil Campbell to Lexington. A slight risk extends to the east up to a line ranging from Geiger to Warrior, passing from Hytop. A marginal risk extends to the east of it up to a line going from a line going from Cuba to Brent to Ider.

The main threats will be severe storm winds up to 70 km / h, large hail and tornadoes, some of which may be strong (especially in areas of increased risk). Today's storms will be around 15:00 to 12:00 for locations at increased risk and from 19:00 to 03:00 for low and marginal risk locations. The threat of severe weather is expected to ease by 3 am Sunday.

The day will be mild and warm in the north and center of Alabama, with peaks reaching the mid-60s in the north and 70s in the south.

At this point, the best instability will spread over most of north / central Alabama during the period from noon to 7 pm. All the activity will be scattered and of a cellular nature, and with the very high helicity of the region, we will have to watch closely the presence of rotating cells. By 18:00, the activity of the storm will pass from a cellular network to a main grain line that will enter the northwest corner of the state. When that happens, the instability will be mostly along the line and right in front of it. The line will weaken when it will move from a diagonal orientation to a horizontal orientation when it moves south-east.

The threat to tornadoes will be highest in risk areas between 12 and 18 hours, with a maximum around 16 hours before starting to fall quickly. The values ​​of the important tornado parameters reach 2.8 in some parts of the area. As the helicity values ​​reach their maximum on the zone at about the same time, the ingredients are present for the potential of strong updraft currents. And the Supercell composite parameter shows the probability for supercells where helicity and shear will be the strongest.

At 6 pm, the line is well formed and begins its journey in the state, then slides and rotates around midnight southeast in the Birmingham metropolitan area. At this point, the line will have significantly decreased, but a single wind-gust of wind and a brief tornado of spin-up can not be ruled out at this stage.

We must be vigilant in the face of severe storms, as we are in our spring season of severe weather in Alabama. If you use the external sirens strictly to receive the warnings, you do not have much hope anymore. Wireless phone alerts (WEA) must be activated on all phones and all homes must have a NOAA weather radio.

Every home also needs a weather safety kit, as well as a ready-to-use action plan if your location is warned. If you live in a mobile home and you are in a polygon, you MUST leave and find safety in a stronger structure or in a tornado shelter. Discuss these things with your household and make sure everyone understands exactly what to do.

SUNDAY

On Sunday, the front and storm line will begin in the morning just south of I-20. The cold front will have already stalled and it will be the catalyst for the development of new storms with the warming of the day before finally starting to move towards the south in the evening and at the end of the night. We witnessed stronger to more violent storms in the southern and southeastern parts of the region, with isolated and damaging winds and a brief tornado of possible spin-up.

SPC has a defined marginal risk for locations south of a line from Selma to Wetumpka to La Fayette. Values ​​of instability and helicity will be much lower and mainly confined along the front and just ahead. The weather for storms to be strong to strong seems to be around 10:00 to 22:00.

North of the front, scattered showers may move into the area, but most of the activity is expected to remain south of I-59. The highs range from the mid-1960s to the 1970s in central Alabama, from the northwest to the southeast.

NEXT WEEK

On Monday, much of the northern half of central Alabama will remain dry all day, but showers may form in the south of the region. No thunder at this stage. Peaks will be between the mid-1960s and the mid-1970s in the region.

Tuesday should be a dry day in central Alabama, pending the installation of our next system in the area by Wednesday night. We can start the day with a shower very early in the morning in the northwest of the region, but these chances to dissipate very quickly after sunrise. The highs range from the mid-60s to the mid-70s.

On Wednesday, we will see a vigorous system gain ground in the west at noon, but it will begin to move into central Alabama towards the end of the night and into the night. Showers and thunderstorms are likely to be late. There will be some instability on the ground, so we may need to monitor the possibility of severe storms. We will have a better idea as we get closer. The highs will be in the 60's to 70's.

On Thursday, the climate continues to be stormy, with rain and thunderstorms throughout the day. The instability will remain in place, so we will have to continue to monitor the possibility of severe storms. The highs will be in the 70s.

The rains and storms will likely continue to occur early Friday before finally having the wind in their sails and leaving the area late in the day. The sky will begin to slowly clear behind activity from northwest to southeast. The highs will be between the mid-sixties and the first seventies.