9/27/24 – Hurricane Helene roared ashore last night and by noon today had triggered flooding in at least eight states, according to the National Weather Service.
Helene Floods Eight States
The states include: Florida, Alabama, Georgia, South Carolina, North Carolina, Tennessee, Virginia and Kentucky. See orange, red and purple areas below.
From NWS Water Prediction Center. Gage data from noon 9/26/24 to noon 9/27/24. Purple = Major Flooding, Red = Moderate, Brown = Minor. Yellow = Action.
Many of those same areas could still see additional rainfall. Through 7 AM CDT, NOAA’s Weather Prediction Center gives 15 states a chance for additional excessive rainfall. See below.
Power Outages and Deaths
Meanwhile, more than 3 million people in affected areas remain without power, according to PowerOutages.US.
The Hill reports that at least 35 people died as a result of the Category 4 storm.
At this hour, NBC puts the death toll at 42 and says more than 4 million people are without power.
USA Today reported within the hour that 4.5 million people have no electricity.
The death toll will likely increase in coming days as rescuers race to free more people trapped in flooded areas.
It could take weeks to restore all the power given the breadth of the devastation. An Associated Press report said that in Georgia, “…an electrical utility group warned of ‘catastrophic’ damage to the state’s utility infrastructure, with more than 100 high voltage transmission lines damaged.”
AP also reported that in South Carolina, “more than 40% of homes and businesses were without power.” They said crews needed to cut their way through debris just to determine what was still standing in some places.
Helene Now a Tropical Depression
At 4 PM, the National Hurricane Center has downgraded Helene to a tropical depression with sustained winds of 35 MPH and forward motion of 17 MPH.
Summary of Weather Stats
For a list of reported rainfall totals to date and peak wind gusts associated with Helene, see this list from the National Centers for Environmental Prediction as of 11 AM EDT 9/27/24. Busick, North Carolina recorded the highest rainfall total to date: 29.58 inches.
All in all, the forecasters predicted Helene’s impacts pretty accurately.
Helene is the latest reminder of why we need to continue fighting for flood mitigation. It could have happened here.
Posted by Bob Rehak on 9/27/24
2586 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/09/20240927-Helene-Flooding.jpg?fit=1100%2C614&ssl=16141100adminadmin2024-09-27 17:01:582024-09-27 17:27:06Helene Triggers Flooding in 8 States, Millions Without Power
9/26/24 5:20 PM CDT Update – Helene has become a Category 4 storm with 130 MPHsustained winds.
According to the National Hurricane Center (NHC), Helene is rapidly becoming one of the “largest hurricanes in decades.” Comparing Helene to previous hurricanes in the Gulf of Mexico, they say, “Helene is at the upper bound in terms of size.”
Widespread Impacts, “Immense Human Suffering”
Helene’s hurricane-force winds extend outward up to 60 miles from the center. And tropical-storm-force winds extend outward up to 345 miles.
“As a result , storm surge, wind, and rainfall impacts will extend far away from the center and well outside the forecast cone, particularly on the east side,” they say.
“In addition, the fast forward speed when Helene moves inland will result in a far inland penetration of strong winds. That includes strong gusts over higher terrain of the southern Appalachians.”
Jeff Lindner, Harris County’s meteorologist, characterized Helene as “extremely dangerous.” He said, “Widespread and significant impacts will produce immense human suffering by modern standards.”
Large parts of the SE US will have a greater than 50% chance of tropical-storm-force or higher winds from Helene.
Already High End of Category 2 at 10 AM
As of 10AM, maximum sustained winds had increased to near 105 MPH with higher gusts. That puts Helene just five miles per hour from becoming a major category three hurricane.
Helene was moving toward the Big Bend area of the Florida Panhandle at 14 MPH and will make landfall this evening. After landfall, Helene should turn northwestward and slow down over the Tennessee Valley on Friday and Saturday.
The minimum central pressure has plummeted to 947 mb.
Additionally, water level rise along the west coast of Florida has begun and will quickly worsen through the day. Catastrophic storm surge will reach up to 15-20 feet above normally dry ground.
Over portions of the Southeastern U.S. into the Southern Appalachians, Helene is expected to produce total rain accumulations of 6 to 12 inches, with isolated totals around 20 inches.
This rainfall will likely result in catastrophic and potentially life-threatening flash and urban flooding, along with significant river flooding. Numerous significant landslides are expected in steep terrain across the southern Appalachians.
Key Messages
A catastrophic and deadly storm surge is likely along portions of the Florida Big Bend coast, where inundation could reach as high as 20 feet above ground level, along with destructive waves. There is also a danger of life-threatening storm surge along the remainder of the west coast of the Florida Peninsula.
Potentially catastrophic hurricane-force winds are expected within the eyewall of Helene when it makes landfall in the Florida Big Bend region this evening. Damaging and life-threatening hurricane-force winds, especially in gusts, will penetrate well inland. Strong wind gusts are also likely farther north across portions of northern Georgia and the Carolinas, particularly over the higher terrain of the southern Appalachians.
Catastrophic and life-threatening flash and urban flooding, including numerous significant landslides, is expected across portions of the southern Appalachians through Friday. Widespread significant river flooding and isolated major river flooding are likely.
Helene in Historical Perspective
All indications at this point suggest Helene will have a huge impact on the southeastern US.
Helene at 10 AM Central Daylight TimeWider shot taken at 5:30 PM CDT slightly before landfall.
“This is likely to be the worst hurricane event for this area in over a generation. Conditions near the coast will not be survivable.”
Jeff Lindner, Harris County Meteorologist
Lindner continued, “Since 1851 there are no records of storms of this magnitude in Apalachee Bay. All coastal structures/infrastructure lower than 15 ft will be completely destroyed. Older slab built structures in this area will suffer catastrophic damage and likely be washed away. Water levels will almost certainly rise to the second floors of elevated structures and some of these will face total collapse. All available efforts should be utilized to evacuate these areas.”
Posted by Bob Rehak on 9/26/24 at 11 AMbased on information from NHC and Harris County
2585 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/09/1000x1000.jpg?fit=1000%2C1000&ssl=110001000adminadmin2024-09-26 11:41:132024-09-26 18:10:54Helene Will Be One of Largest Hurricanes in Decades
9/25/24 3PM CDT – Today, Helene intensified into a hurricane and it should become a major hurricane before making landfall tomorrow in the Big Bend area of the Florida Panhandle. Some forecasters are predicting a Category 3 storm, others a Cat 4.
Helene will accelerate to the north today and Thursday crossing the entire Gulf of Mexico in a 24-30 hour period and reach the Florida Gulf coast late Thursday, according to the National Hurricane Center (NHC).
Warm Waters Will Fuel Rapid Intensification
Harris County Meteorologist Jeff Lindner says, “Helene will be passing over extremely warm waters that extend 100-200 feet deep. That supports great levels of intensity in developing hurricanes. Nearly all the hurricane intensity models bring Helene to Category 4 over the eastern Gulf of Mexico. The official forecast is for a 120mph category 3, but this may need to be adjusted upward given current trends and guidance.”
Regardless, all forecasters comment on the size of Helene. At 1PM, tropical storm force winds extended outward 275 miles from the center, according to NHC.
Hurricane Helene as of 1PM CDT on 9/25/24
As a result, they predict Helene’s impacts will extend well inland. Tropical storm force winds will likely reach Atlanta and even the southern Appalachian Mountains.
Life-Threatening Storm Surge
But the most certain threats to life and property have to do with storm surge. Today forecasters say it could reach up to 20 feet above land; yesterday it was 15.
Jeff Lindner, Harris County’s meteorologist says, “Structures lower than 10 ft will be completely destroyed along the entire Florida nature coast. This will potentially be a record storm surge event for the eastern side of the Florida Big Bend, likely surpassing previous records from the March 1993 ‘superstorm’ surge event.”
Torrential Rain and Flash-Flood Threats
Farther inland, the threat will be torrential rains. Atlanta, which usually doesn’t experience tropical threats, could receive 8-12 inches with higher isolated totals. Areas in the mountains north of Atlanta could receive 16-20 inches.
A potentially catastrophic inland flash flood event is becoming increasingly likely as Helene interacts with a stalled frontal boundary and the higher terrain of the southern Appalachian mountains from northern Georgia into western North Carolina and eastern Tennessee.
In the rainfall map above, note the red and brown colored areas along the North Carolina/Tennessee border. That is a mountainous region.
The excessive rainfall there is orographic in origin. Orographic means precipitation caused by hills or mountain ranges deflecting moisture-laden air masses upward, causing them to cool and precipitate their moisture.
All that precipitation will likely trigger flash flooding.
Widespread travel disruption is likely over the southeast from Thursday into Saturday. Recovery of essential services will be slow due to the widespread, significant impacts.
Key Messages
The NHC warns:
Due to the large size of Helene, there is a danger of life-threatening storm surge along the entire west coast of the Florida Peninsula and Florida Big Bend. Residents should follow the evacuation advice of local officials.
Devastating hurricane-force winds will reach from northern Florida into southern Georgia. Because of Helene’s expected fast forward speed, damaging and life-threatening wind gusts are expected to penetrate well inland to the southern Appalachians.
Helene will bring heavy rain and potentially life-threatening flash and urban flooding. Impacts will stretch across portions of northwestern and northern Florida, the Southeast, southern Appalachians, and the Upper Tennessee Valley Wednesday through Friday.
Widespread minor to moderate river flooding is likely, and isolated major river flooding is possible.
Types of Damage Associated with Category 4 Hurricanes
The National Weather Service lists types of damage typically associated with a Category 4 Hurricane. “Winds 130-156 mph. Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.”
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/09/Hurricane-Helene.jpg?fit=1100%2C740&ssl=17401100adminadmin2024-09-25 15:00:272024-09-25 21:16:38Helene Now a Hurricane 550 Miles Across, Impacts Will Spread Far Inland
Helene Triggers Flooding in 8 States, Millions Without Power
9/27/24 – Hurricane Helene roared ashore last night and by noon today had triggered flooding in at least eight states, according to the National Weather Service.
Helene Floods Eight States
The states include: Florida, Alabama, Georgia, South Carolina, North Carolina, Tennessee, Virginia and Kentucky. See orange, red and purple areas below.
Many of those same areas could still see additional rainfall. Through 7 AM CDT, NOAA’s Weather Prediction Center gives 15 states a chance for additional excessive rainfall. See below.
Power Outages and Deaths
Meanwhile, more than 3 million people in affected areas remain without power, according to PowerOutages.US.
The Hill reports that at least 35 people died as a result of the Category 4 storm.
At this hour, NBC puts the death toll at 42 and says more than 4 million people are without power.
USA Today reported within the hour that 4.5 million people have no electricity.
The death toll will likely increase in coming days as rescuers race to free more people trapped in flooded areas.
It could take weeks to restore all the power given the breadth of the devastation. An Associated Press report said that in Georgia, “…an electrical utility group warned of ‘catastrophic’ damage to the state’s utility infrastructure, with more than 100 high voltage transmission lines damaged.”
AP also reported that in South Carolina, “more than 40% of homes and businesses were without power.” They said crews needed to cut their way through debris just to determine what was still standing in some places.
Helene Now a Tropical Depression
At 4 PM, the National Hurricane Center has downgraded Helene to a tropical depression with sustained winds of 35 MPH and forward motion of 17 MPH.
Summary of Weather Stats
For a list of reported rainfall totals to date and peak wind gusts associated with Helene, see this list from the National Centers for Environmental Prediction as of 11 AM EDT 9/27/24. Busick, North Carolina recorded the highest rainfall total to date: 29.58 inches.
All in all, the forecasters predicted Helene’s impacts pretty accurately.
Helene is the latest reminder of why we need to continue fighting for flood mitigation. It could have happened here.
Posted by Bob Rehak on 9/27/24
2586 Days since Hurricane Harvey
Helene Will Be One of Largest Hurricanes in Decades
9/26/24 5:20 PM CDT Update – Helene has become a Category 4 storm with 130 MPH sustained winds.
According to the National Hurricane Center (NHC), Helene is rapidly becoming one of the “largest hurricanes in decades.” Comparing Helene to previous hurricanes in the Gulf of Mexico, they say, “Helene is at the upper bound in terms of size.”
Widespread Impacts, “Immense Human Suffering”
Helene’s hurricane-force winds extend outward up to 60 miles from the center. And tropical-storm-force winds extend outward up to 345 miles.
“As a result , storm surge, wind, and rainfall impacts will extend far away from the center and well outside the forecast cone, particularly on the east side,” they say.
“In addition, the fast forward speed when Helene moves inland will result in a far inland penetration of strong winds. That includes strong gusts over higher terrain of the southern Appalachians.”
Jeff Lindner, Harris County’s meteorologist, characterized Helene as “extremely dangerous.” He said, “Widespread and significant impacts will produce immense human suffering by modern standards.”
Already High End of Category 2 at 10 AM
As of 10AM, maximum sustained winds had increased to near 105 MPH with higher gusts. That puts Helene just five miles per hour from becoming a major category three hurricane.
Helene was moving toward the Big Bend area of the Florida Panhandle at 14 MPH and will make landfall this evening. After landfall, Helene should turn northwestward and slow down over the Tennessee Valley on Friday and Saturday.
The minimum central pressure has plummeted to 947 mb.
Additionally, water level rise along the west coast of Florida has begun and will quickly worsen through the day. Catastrophic storm surge will reach up to 15-20 feet above normally dry ground.
Over portions of the Southeastern U.S. into the Southern Appalachians, Helene is expected to produce total rain accumulations of 6 to 12 inches, with isolated totals around 20 inches.
This rainfall will likely result in catastrophic and potentially life-threatening flash and urban flooding, along with significant river flooding. Numerous significant landslides are expected in steep terrain across the southern Appalachians.
Key Messages
Helene in Historical Perspective
All indications at this point suggest Helene will have a huge impact on the southeastern US.
Lindner continued, “Since 1851 there are no records of storms of this magnitude in Apalachee Bay. All coastal structures/infrastructure lower than 15 ft will be completely destroyed. Older slab built structures in this area will suffer catastrophic damage and likely be washed away. Water levels will almost certainly rise to the second floors of elevated structures and some of these will face total collapse. All available efforts should be utilized to evacuate these areas.”
Posted by Bob Rehak on 9/26/24 at 11 AM based on information from NHC and Harris County
2585 Days since Hurricane Harvey
Helene Now a Hurricane 550 Miles Across, Impacts Will Spread Far Inland
9/25/24 3PM CDT – Today, Helene intensified into a hurricane and it should become a major hurricane before making landfall tomorrow in the Big Bend area of the Florida Panhandle. Some forecasters are predicting a Category 3 storm, others a Cat 4.
Helene will accelerate to the north today and Thursday crossing the entire Gulf of Mexico in a 24-30 hour period and reach the Florida Gulf coast late Thursday, according to the National Hurricane Center (NHC).
Warm Waters Will Fuel Rapid Intensification
Harris County Meteorologist Jeff Lindner says, “Helene will be passing over extremely warm waters that extend 100-200 feet deep. That supports great levels of intensity in developing hurricanes. Nearly all the hurricane intensity models bring Helene to Category 4 over the eastern Gulf of Mexico. The official forecast is for a 120mph category 3, but this may need to be adjusted upward given current trends and guidance.”
The wind speed break point between Categories 3 and 4 is 130 MPH.
Impacts Will Be Felt Far Inland
Regardless, all forecasters comment on the size of Helene. At 1PM, tropical storm force winds extended outward 275 miles from the center, according to NHC.
As a result, they predict Helene’s impacts will extend well inland. Tropical storm force winds will likely reach Atlanta and even the southern Appalachian Mountains.
Life-Threatening Storm Surge
But the most certain threats to life and property have to do with storm surge. Today forecasters say it could reach up to 20 feet above land; yesterday it was 15.
Jeff Lindner, Harris County’s meteorologist says, “Structures lower than 10 ft will be completely destroyed along the entire Florida nature coast. This will potentially be a record storm surge event for the eastern side of the Florida Big Bend, likely surpassing previous records from the March 1993 ‘superstorm’ surge event.”
Torrential Rain and Flash-Flood Threats
Farther inland, the threat will be torrential rains. Atlanta, which usually doesn’t experience tropical threats, could receive 8-12 inches with higher isolated totals. Areas in the mountains north of Atlanta could receive 16-20 inches.
A potentially catastrophic inland flash flood event is becoming increasingly likely as Helene interacts with a stalled frontal boundary and the higher terrain of the southern Appalachian mountains from northern Georgia into western North Carolina and eastern Tennessee.
In the rainfall map above, note the red and brown colored areas along the North Carolina/Tennessee border. That is a mountainous region.
The excessive rainfall there is orographic in origin. Orographic means precipitation caused by hills or mountain ranges deflecting moisture-laden air masses upward, causing them to cool and precipitate their moisture.
All that precipitation will likely trigger flash flooding.
Widespread travel disruption is likely over the southeast from Thursday into Saturday. Recovery of essential services will be slow due to the widespread, significant impacts.
Key Messages
The NHC warns:
Types of Damage Associated with Category 4 Hurricanes
The National Weather Service lists types of damage typically associated with a Category 4 Hurricane. “Winds 130-156 mph. Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.”
Sounds a lot like Beryl.
Posted by Bob Rehak on 9/25/24
2584 Days since Hurricane Harvey