Severe weather outbreak threatens to mar Easter weekend across the South
By
Alex Sosnowski, AccuWeather senior meteorologist
Published Apr 8, 2020 5:34 PM EDT
Portions of the southern United States will need to brace for a potentially significant, multi-day severe weather outbreak that could bring the threat of strong tornadoes due to cold air easing its grip across the Gulf states just as many Americans are preparing to observe Easter services.
Dry and chilly air, more typical of late February and early March, will sweep across much of the Central and Eastern states to end this week. Even though the cold air may stabilize the atmosphere enough to prevent severe weather across much of the Midwest and part of the East, it could make matters worse in the Interstate 10 and 20 corridors of the South.
An unusually strong storm for April, affecting California and the Southwest into the end of this week, will begin to move eastward this weekend. As this occurs, the circulation around the storm will begin to pump warmer, more humid air northward around the Gulf of Mexico.
The setup could create enough extra spin in the atmosphere over part of the Deep South to bring thunderstorms with not only big hail, damaging wind gusts and flash flooding but also the potential for tornadoes on Saturday, Sunday and Monday.
“I’m growing very worried about the possibility of tornadoes,” AccuWeather Chief Broadcast Meteorologist Bernie Rayno said. ”So, I think there’s going to be widespread severe weather in this area anyway, but I am growing concerned about the tornado threat. That would be Sunday afternoon and Sunday night."
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Near the edge of cool air and just south of that zone, enough wind shear could develop to cause rotating thunderstorms, which can then spawn tornadoes. The change in wind speed and direction at different altitudes in the atmosphere is know as wind shear.
A rotating supercell thunderstorm. (NOAA's National Severe Storms Laboratory / Mike Coniglio)
There is some uncertainty as to the number of tornadoes and how far north the severe weather risk may extend into the chilly air, but thunderstorms are likely to pose a significant risk to lives and property in the South this weekend as the most significant outbreak of severe weather yet this year may unfold.
"Confidence is growing that we are looking for multiple tornadoes on the ground Sunday, and there is a possibility that this will be a tornado outbreak," Rayno said. The American Meteorological Society (AMS) defines a tornado outbreak as 10 or more twisters touching down from the same weather system.
The first storms during the outbreak are forecast to erupt from portions of central and eastern Texas to the Mississippi Delta region during late Saturday afternoon and night.
There may also be a few isolated severe storms that erupt farther to the west, near the leading edge of dry air over western Texas and central Oklahoma, during Saturday afternoon.
Easter Sunday could be a big and dangerous day for severe weather as millions focus on the religious holiday and family members.
"Sunday looks to be a significant severe weather day, specifically for the lower Mississippi Valley into the lower part of Tennessee River Valley, central Gulf Coast and southern Appalachians," Eddie Walker, AccuWeather forecaster, said.
"Strong atmospheric dynamics paired with high shear, plenty of moisture and sufficient instability will develop severe thunderstorms early, continuing all of the day into Sunday night," Walker said.
All modes of severe weather are expected, including large hail, flooding, damaging winds and tornadoes on Sunday.
The greatest risk of tornadoes will stretch from central Louisiana to western Georgia and includes south-central Tennessee, a state that has been hit hard by twisters. Areas south of Nashville, which was slammed in early March by the deadliest tornado to hit the community in nearly 11 years, are included in the highest risk zone.
Major cities such as Atlanta; Birmingham, Alabama; Jackson, Mississippi, and others will be at risk for the storms on Sunday.
The setup could produce tornadoes that are on the ground for more than a few minutes. There is the risk of strong, long-track tornadoes and the likelihood of some of the tornadoes persisting after dark, which will add to the danger.
The risk will advance to the northeastern Gulf Coast, Piedmont and part of the southern Atlantic coast after dark on Sunday, which may add to the danger. The severe thunderstorm and tornado risk may extend to Greenville, South Carolina, and Charlotte, North Carolina, Sunday evening.
"There is the possibility that cloudy, rainy and cool conditions could greatly limit severe thunderstorms north of Interstate 20 or prevent them from erupting all at once like a swarm," Walker said.
Where the wedge of cool air holds on, excessive rainfall, flash flooding and river flooding may be the greatest threats, rather than violent thunderstorms and tornadoes. If the storm were to hug the upper Gulf Coast, rather than track along I-20, then this scenario could unfold across much of the South.
Should the system cut well to the north over the Central states, then the risk of severe weather may correspondingly expand or shift northward toward the middle Mississippi Valley, the upper part of Tennessee Valley and even the Ohio Valley on Sunday and Sunday night.
Along with the risk of violent storms, enough moisture will be available in the atmosphere to produce heavy rainfall from eastern Texas to the coastal Northeast as the system moves along.
A general 1-3 inches of rain is likely to fall with the storms with an AccuWeather Local StormMax™ of 6 inches most likely over the interior Southeast states.
The severe weather risk is eventually likely to lunge northward along the Atlantic coast, associated with a northward surge of warm air east of the Appalachians.
For this reason, the risk of severe thunderstorms, perhaps with a couple of brief, spin-up tornadoes, may reach as far north as the mid-Atlantic coast for a time on Monday.
The tail end of the severe thunderstorms may also extend southward and advance across northern Florida on Monday.
Tornado-related fatalities have occurred in every month of the year across the U.S., April is one of the deadliest months for twisters, and April is notoriously a troublesome month for tornadoes in the Southern states.
While tens of millions of people are concerned about the risks associated with COVID-19, conditions can change rapidly this weekend, and forecasters urge Americans to pay close attention to and heed all severe thunderstorm and tornado warnings. In the age of social distancing, it's more important than ever to have a severe weather plan in place ahead of an outbreak as storm shelters may be closed.
AccuWeather is offering free severe weather service for hospitals medical facilities and public health agencies due to the number of temporary COVID-19 triage and testing facilities that have been set up outdoors and may be especially vulnerable during severe thunderstorms and other high-wind situations.
The severe weather and tornado potential could evolve into a very dangerous and deadly situation this weekend.
AccuWeather will continue to provide updates on the severe weather threats in the coming days, including any short-terms risks, which could put over 70 million Americans at risk.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
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News / Severe Weather
Severe weather outbreak threatens to mar Easter weekend across the South
By Alex Sosnowski, AccuWeather senior meteorologist
Published Apr 8, 2020 5:34 PM EDT
Portions of the southern United States will need to brace for a potentially significant, multi-day severe weather outbreak that could bring the threat of strong tornadoes due to cold air easing its grip across the Gulf states just as many Americans are preparing to observe Easter services.
Dry and chilly air, more typical of late February and early March, will sweep across much of the Central and Eastern states to end this week. Even though the cold air may stabilize the atmosphere enough to prevent severe weather across much of the Midwest and part of the East, it could make matters worse in the Interstate 10 and 20 corridors of the South.
An unusually strong storm for April, affecting California and the Southwest into the end of this week, will begin to move eastward this weekend. As this occurs, the circulation around the storm will begin to pump warmer, more humid air northward around the Gulf of Mexico.
The setup could create enough extra spin in the atmosphere over part of the Deep South to bring thunderstorms with not only big hail, damaging wind gusts and flash flooding but also the potential for tornadoes on Saturday, Sunday and Monday.
“I’m growing very worried about the possibility of tornadoes,” AccuWeather Chief Broadcast Meteorologist Bernie Rayno said. ”So, I think there’s going to be widespread severe weather in this area anyway, but I am growing concerned about the tornado threat. That would be Sunday afternoon and Sunday night."
CLICK HERE FOR THE FREE ACCUWEATHER APP
Near the edge of cool air and just south of that zone, enough wind shear could develop to cause rotating thunderstorms, which can then spawn tornadoes. The change in wind speed and direction at different altitudes in the atmosphere is know as wind shear.
A rotating supercell thunderstorm. (NOAA's National Severe Storms Laboratory / Mike Coniglio)
There is some uncertainty as to the number of tornadoes and how far north the severe weather risk may extend into the chilly air, but thunderstorms are likely to pose a significant risk to lives and property in the South this weekend as the most significant outbreak of severe weather yet this year may unfold.
"Confidence is growing that we are looking for multiple tornadoes on the ground Sunday, and there is a possibility that this will be a tornado outbreak," Rayno said. The American Meteorological Society (AMS) defines a tornado outbreak as 10 or more twisters touching down from the same weather system.
The first storms during the outbreak are forecast to erupt from portions of central and eastern Texas to the Mississippi Delta region during late Saturday afternoon and night.
There may also be a few isolated severe storms that erupt farther to the west, near the leading edge of dry air over western Texas and central Oklahoma, during Saturday afternoon.
Easter Sunday could be a big and dangerous day for severe weather as millions focus on the religious holiday and family members.
"Sunday looks to be a significant severe weather day, specifically for the lower Mississippi Valley into the lower part of Tennessee River Valley, central Gulf Coast and southern Appalachians," Eddie Walker, AccuWeather forecaster, said.
"Strong atmospheric dynamics paired with high shear, plenty of moisture and sufficient instability will develop severe thunderstorms early, continuing all of the day into Sunday night," Walker said.
All modes of severe weather are expected, including large hail, flooding, damaging winds and tornadoes on Sunday.
The greatest risk of tornadoes will stretch from central Louisiana to western Georgia and includes south-central Tennessee, a state that has been hit hard by twisters. Areas south of Nashville, which was slammed in early March by the deadliest tornado to hit the community in nearly 11 years, are included in the highest risk zone.
Major cities such as Atlanta; Birmingham, Alabama; Jackson, Mississippi, and others will be at risk for the storms on Sunday.
The setup could produce tornadoes that are on the ground for more than a few minutes. There is the risk of strong, long-track tornadoes and the likelihood of some of the tornadoes persisting after dark, which will add to the danger.
The risk will advance to the northeastern Gulf Coast, Piedmont and part of the southern Atlantic coast after dark on Sunday, which may add to the danger. The severe thunderstorm and tornado risk may extend to Greenville, South Carolina, and Charlotte, North Carolina, Sunday evening.
"There is the possibility that cloudy, rainy and cool conditions could greatly limit severe thunderstorms north of Interstate 20 or prevent them from erupting all at once like a swarm," Walker said.
Related:
Where the wedge of cool air holds on, excessive rainfall, flash flooding and river flooding may be the greatest threats, rather than violent thunderstorms and tornadoes. If the storm were to hug the upper Gulf Coast, rather than track along I-20, then this scenario could unfold across much of the South.
Should the system cut well to the north over the Central states, then the risk of severe weather may correspondingly expand or shift northward toward the middle Mississippi Valley, the upper part of Tennessee Valley and even the Ohio Valley on Sunday and Sunday night.
Along with the risk of violent storms, enough moisture will be available in the atmosphere to produce heavy rainfall from eastern Texas to the coastal Northeast as the system moves along.
A general 1-3 inches of rain is likely to fall with the storms with an AccuWeather Local StormMax™ of 6 inches most likely over the interior Southeast states.
The severe weather risk is eventually likely to lunge northward along the Atlantic coast, associated with a northward surge of warm air east of the Appalachians.
For this reason, the risk of severe thunderstorms, perhaps with a couple of brief, spin-up tornadoes, may reach as far north as the mid-Atlantic coast for a time on Monday.
The tail end of the severe thunderstorms may also extend southward and advance across northern Florida on Monday.
Tornado-related fatalities have occurred in every month of the year across the U.S., April is one of the deadliest months for twisters, and April is notoriously a troublesome month for tornadoes in the Southern states.
While tens of millions of people are concerned about the risks associated with COVID-19, conditions can change rapidly this weekend, and forecasters urge Americans to pay close attention to and heed all severe thunderstorm and tornado warnings. In the age of social distancing, it's more important than ever to have a severe weather plan in place ahead of an outbreak as storm shelters may be closed.
AccuWeather is offering free severe weather service for hospitals medical facilities and public health agencies due to the number of temporary COVID-19 triage and testing facilities that have been set up outdoors and may be especially vulnerable during severe thunderstorms and other high-wind situations.
The severe weather and tornado potential could evolve into a very dangerous and deadly situation this weekend.
AccuWeather will continue to provide updates on the severe weather threats in the coming days, including any short-terms risks, which could put over 70 million Americans at risk.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo