9/24/24 at 1 PM – This morning, Potential Tropical Cyclone 9 became Tropical Storm Helene when satellite images and Hurricane Hunter aircraft data noted a well-defined center of circulation and sustained winds of 45 MPH with higher gusts.
Helene is moving toward the northwest near 12 mph and will likely continue to do so through early Wednesday. The National Hurricane Center expects northward to north-northeastward motion at a faster forward speed on Wednesday and Thursday.
On the forecast track, the center of Helene will move across the far northwestern Caribbean Sea through tonight, and then move across the eastern Gulf of Mexico Wednesday and Thursday, potentially reaching the Gulf coast of Florida late Thursday.
Additional strengthening is forecast. Helene should become a hurricane on Wednesday and could become a major hurricane on Thursday.
A major factor in the forecast of hazards is the size of the storm. Currently, tropical-storm-force winds extend outward up to 140 miles to the east of the center. Helene’s forecast radii are at the 90th percentile of hurricane size at similar latitudes. If accurate, that means only 10% of hurricanes will exceed its size.
Due to the forecast large size of this system, storm surge, wind, and rainfall impacts will extend well away from the center, particularly on the east side.
Hazards Affecting Land
Rainfall
Heads up if you have friends, family or travel plans in the southeast this week. Helene should produce total rain accumulations of 4 to 8 inches with isolated totals around 12 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with minor to moderate river flooding likely, and isolated major river flooding possible.
The combination of a dangerous storm surge and high tide will cause normally dry areas near the coast to flood. The water could reach 10-15 feet above ground between Ochlockonee River, FL and Chassahowitzka. For other areas see the map below.
Hurricane conditions are possible within the U.S. watch areas Wednesday night and early Thursday.
Tropical storm conditions should hit the Lower Florida Keys beginning Wednesday, and are possible in the watch area in the Middle Florida Keys beginning late Wednesday.
Helene should make landfall in the Panhandle Thursday morning and reach Atlanta by Thursday evening or Friday morning.
Compared to yesterday’s forecast, the chance of damaging winds now extends much farther north, well into Georgia.
The fast forward speed of the storm when it crosses the coast will likely result in inland penetration of strong winds over parts of the southeastern United States well after landfall.
Surf
Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast on Wednesday and Thursday. These swells are likely to cause life-threatening surf and rip current conditions.
Intensification
Several factors suggest rapid intensification of Helene:
Shear over the system will decrease. Model guidance continues to show relatively low to moderate shear for the next 48 hours or so.
Oceanic heat content values are very high.
The system will move through an environment of upper-level divergence.
Therefore, NHC anticipates significant strengthening. NHC’s intensity forecast shows the system reaching a peak intensity around 100 kt (116 MPH) in 48 hours while over the eastern Gulf of Mexico.
Given the system’s large size, it might only weaken slowly even if it encounters sheer near the Panhandle. As a result, there is still a risk that the system could reach the coast as a major hurricane.
Key Messages
1. Helene will be near hurricane strength early Wednesday when it shoots the gap between the Yucatan and Cuba.
2. Helene should rapidly intensify over the eastern Gulf and become a major Category 3 hurricane as it approaches the coast on Thursday. The risk of life-threatening storm surge and damaging hurricane-force winds continues to increase along the coast of the Florida Panhandle and Florida’s west coast. Hurricane and Storm Surge Watches are in effect for much of that area. Residents should follow advice given by local officials.
3. Helene will bring heavy rain which will likely result in locally considerable flash and urban flooding across portions of Florida, with isolated flash and urban flooding possible across the Southeast, Southern Appalachians, and the Tennessee Valley Wednesday through Friday. Minor to isolated moderate river flooding will also be possible.
Here’s what Helene looked like this morning from space.
Helene as of 10AM 9/24/24 CDT circled in red.
Posted by Bob Rehak at 1 PM on 9/24/24
2584 Days since Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/09/TS-Helene.jpg?fit=1100%2C723&ssl=17231100adminadmin2024-09-24 13:03:342024-09-24 13:15:22TS Helene Pushing North, Intensifying, Expanding
9/23/24 at 12 PM – The National Hurricane Center has designated a disturbance in the northwestern Caribbean as Potential Tropical Cyclone 9. Currently, NHC gives the storm a 90% chance of development in the next two days.
According to Harris County Meteorologist Jeff Lindner, models indicate it will likely escalate into a Category 4 hurricane as it heads north over the warm waters of the Gulf.
However, it will likely make landfall along the Florida Panhandle. Current forecasts indicate no threat to Texas. Overnight, the projected track of the storm shifted farther east.
Projections as of Noon Monday
I’m posting this because Houston residents may have friends, relatives or travel plans in affected areas. See below.
Center of storm has equal change of tracking anywhere within cone. Cone does not indicate width of storm.
Tropical storm force winds associated with Potential Tropical Cyclone 9 should arrive in the big bend area of the Florida panhandle sometime between Wednesday night and Thursday morning.
NHC predicts a 50:50 chance for tropical storm force winds extending north into Georgia.
The National Weather Service has this to say for people in the Panhandle and southern Georgia, “There is a potential for significant storm surge; heavy rainfall and flooding; and strong winds across the north and eastern Gulf Coast.”
“Impacts could begin as early as Wednesday night and last into Friday,” says NWS. “More detailed and specific impacts will be highly dependent on future track/intensity and we’ll be including those in future updates in the next day or two.”
Winds have a 95 percent chance of a 75 MPH increase during the next 72 hours.
National Hurricane Center
Frequency of Major Hurricanes
When/if the Potential Tropical Cyclone 9 reaches 39 MPH, NHC will dub it Helene.
We’ve already had one major hurricane in the Gulf this year – Beryl. The second major hurricane usually develops in the Atlantic Basin by September 19. So, even though this season has fewer than normal named storms, it will have an average number of major hurricanes for this part of the season if Helene becomes a Category 3 or higher.
At present, NHC says the area of concern in the northwestern Caribbean between Honduras and Cuba continues to produce disorganized showers and thunderstorms. Some mid-level rotation is evident in visible satellite images.
A gradual turn toward the northwest is expected during the next day or so. Models agree that the center of the system should reach the northeast Gulf on Thursday.
Since the disturbance currently lacks a well-defined center, future track adjustments may be required. Given the large size of the tropical-storm-force wind field and fast forward speed that is forecast, storm surge, wind, and rainfall impacts will likely extend well away from the center, particularly to the east of the system.
While the system is currently broad and not well organized, the models suggest a more well-defined center should develop during the next day or so.
Once the system becomes better organized and develops an inner core, the environmental and oceanic conditions appear favorable for significant strengthening. The sea surface temperature anomaly chart below shows that temperatures in the Caribbean and Gulf are up to 8 degrees Fahrenheit warmer than average for this time of year.
An Air Force Reserve reconnaissance aircraft will investigate the system this afternoon.
Tropical Storm Warnings and Hurricane Watches have already been issued for portions of western Cuba and the Yucatan Peninsula of Mexico.
Key Messages
The disturbance will strengthen and be near hurricane strength when it reaches the far northwestern Caribbean Sea Tuesday night.
The system will intensify and could become a major hurricane when it reaches the northeastern Gulf Coast on Thursday.
There is an increasing risk of life-threatening storm surge and damaging hurricane-force winds along portions of the northern and northeastern Gulf Coast, including the Florida Panhandle and portions of the Florida west coast. But it is too soon to specify the exact location and magnitude of impacts.
Potential Tropical Cyclone Nine will bring heavy rain to portions of the western Caribbean. That may lead to flooding and possible mudslides in western Cuba.
Potential Tropical Cyclone Nine will likely produce total rain accumulations of 4 to 8 inches over western Cuba and the Cayman Islands with isolated totals around 12 inches.
Heavy rainfall will spread into the Southeast U.S. starting on Wednesday and continuing through Friday, bringing a risk of flash and river flooding.
For the latest rainfall forecasts associated with Potential Tropical Cyclone Nine, see the National Weather Service Storm Total Rainfall Graphics.
Posted by Bob Rehak on 9/23/24
2582 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/09/153941_5day_cone_no_line_and_wind.png?fit=897%2C736&ssl=1736897adminadmin2024-09-23 12:40:592024-09-23 16:50:08NHC Issues Advisory on Potential Tropical Cyclone 9
9/22/2024 at 6PM – The National Hurricane Center (NHC) issued a 2PM update today that warns of an 80% chance of a potential new tropical system forming in the seven days. They give the new tropical system a 40% chance in the next two days. The system is now centered in the northwestern Caribbean between Honduras and Cuba.
However, NHC predicts the storm will track somewhere between New Orleans and the Florida Panhandle. While it is no immediate threat to Texas, residents should keep an eye on developments in the next few days, they say.
NHC Graphics
Two-day outlook gives system a 40% chance of development.Seven-day outlook gives the system an 80% chance.
Favorable Environmental Conditions
NHC predicts the track will bend east after crossing between the Yucatan and the western tip of Cuba.
“Disorganized showers and thunderstorms located over the northwestern Caribbean Sea and portions of Central America are associated with a broad area of low pressure,” they say. “Environmental conditions appear favorable for development of this system, and a tropical depression or tropical storm is likely to form during the next few days…”
Regardless of development, this disturbance will produce heavy rains over portions of Central America during the next several days. Interests in the northwestern Caribbean, Yucatan Peninsula, and western Cuba should closely monitor the progress of this feature.
Later this week, the system should move generally northward across the Gulf of Mexico, and “interests along the northern and northeastern Gulf Coast should also monitor the progress of this system.”
Potential system in center of frame could be pulled north and east by an exiting low-pressure system that now stretches from West Texas to New Englandnear top of frame.
Local Impacts Seen as Limited As of Now
Jeff Lindner, Harris County’s meteorologist, said, “The system should lift northward over the Gulf of Mexico by mid to late week. A large upper level low over the southern plains will help draw the tropical system north of northeast toward the US Gulf coast.”
Lindner added that most models are in agreement at this point which makes confidence fairly high. However, he also said, “There may be some small differences in the ultimate track toward the US Gulf coast.”
He concluded, “Guidance also suggests this will be a large tropical system which is capable of moving huge amounts of water in the Gulf.”
“With the current higher than normal fall lunar tides in place, there is some potential for elevated tides along the Texas coast late this week, even for a tropical system passing well to our east.”
If this system turns into a named storm, it will become Helene.
Everyone predicted a severe hurricane season this year, but so far, it has not materialized. On average, we have our tenth named storm by now. See below.
All last week, forecasters warned that this storm had a chance of development. And on most days, the chances increased. Keep your eye on this one!
Posted by Bob Rehak on 9/22/24
2581 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/09/two_atl_7d0-2.png?fit=900%2C665&ssl=1665900adminadmin2024-09-22 18:30:362024-09-22 18:30:37Potential New Tropical System Headed Toward Central Gulf
TS Helene Pushing North, Intensifying, Expanding
9/24/24 at 1 PM – This morning, Potential Tropical Cyclone 9 became Tropical Storm Helene when satellite images and Hurricane Hunter aircraft data noted a well-defined center of circulation and sustained winds of 45 MPH with higher gusts.
Helene is moving toward the northwest near 12 mph and will likely continue to do so through early Wednesday. The National Hurricane Center expects northward to north-northeastward motion at a faster forward speed on Wednesday and Thursday.
On the forecast track, the center of Helene will move across the far northwestern Caribbean Sea through tonight, and then move across the eastern Gulf of Mexico Wednesday and Thursday, potentially reaching the Gulf coast of Florida late Thursday.
Additional strengthening is forecast. Helene should become a hurricane on Wednesday and could become a major hurricane on Thursday.
A major factor in the forecast of hazards is the size of the storm. Currently, tropical-storm-force winds extend outward up to 140 miles to the east of the center. Helene’s forecast radii are at the 90th percentile of hurricane size at similar latitudes. If accurate, that means only 10% of hurricanes will exceed its size.
Due to the forecast large size of this system, storm surge, wind, and rainfall impacts will extend well away from the center, particularly on the east side.
Hazards Affecting Land
Rainfall
Heads up if you have friends, family or travel plans in the southeast this week. Helene should produce total rain accumulations of 4 to 8 inches with isolated totals around 12 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with minor to moderate river flooding likely, and isolated major river flooding possible.
Flash-Flood Risk
Most of the Florida Panhandle and Georgia have a moderate (40-70%) chance of flash flooding.
Storm Surge
The combination of a dangerous storm surge and high tide will cause normally dry areas near the coast to flood. The water could reach 10-15 feet above ground between Ochlockonee River, FL and Chassahowitzka. For other areas see the map below.
Wind
Hurricane conditions are possible within the U.S. watch areas Wednesday night and early Thursday.
Tropical storm conditions should hit the Lower Florida Keys beginning Wednesday, and are possible in the watch area in the Middle Florida Keys beginning late Wednesday.
Helene should make landfall in the Panhandle Thursday morning and reach Atlanta by Thursday evening or Friday morning.
Compared to yesterday’s forecast, the chance of damaging winds now extends much farther north, well into Georgia.
The fast forward speed of the storm when it crosses the coast will likely result in inland penetration of strong winds over parts of the southeastern United States well after landfall.
Surf
Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast on Wednesday and Thursday. These swells are likely to cause life-threatening surf and rip current conditions.
Intensification
Several factors suggest rapid intensification of Helene:
Therefore, NHC anticipates significant strengthening. NHC’s intensity forecast shows the system reaching a peak intensity around 100 kt (116 MPH) in 48 hours while over the eastern Gulf of Mexico.
Given the system’s large size, it might only weaken slowly even if it encounters sheer near the Panhandle. As a result, there is still a risk that the system could reach the coast as a major hurricane.
Key Messages
1. Helene will be near hurricane strength early Wednesday when it shoots the gap between the Yucatan and Cuba.
2. Helene should rapidly intensify over the eastern Gulf and become a major Category 3 hurricane as it approaches the coast on Thursday. The risk of life-threatening storm surge and damaging hurricane-force winds continues to increase along the coast of the Florida Panhandle and Florida’s west coast. Hurricane and Storm Surge Watches are in effect for much of that area. Residents should follow advice given by local officials.
3. Helene will bring heavy rain which will likely result in locally considerable flash and urban flooding across portions of Florida, with isolated flash and urban flooding possible across the Southeast, Southern Appalachians, and the Tennessee Valley Wednesday through Friday. Minor to isolated moderate river flooding will also be possible.
Here’s what Helene looked like this morning from space.
Posted by Bob Rehak at 1 PM on 9/24/24
2584 Days since Harvey
NHC Issues Advisory on Potential Tropical Cyclone 9
9/23/24 at 12 PM – The National Hurricane Center has designated a disturbance in the northwestern Caribbean as Potential Tropical Cyclone 9. Currently, NHC gives the storm a 90% chance of development in the next two days.
According to Harris County Meteorologist Jeff Lindner, models indicate it will likely escalate into a Category 4 hurricane as it heads north over the warm waters of the Gulf.
However, it will likely make landfall along the Florida Panhandle. Current forecasts indicate no threat to Texas. Overnight, the projected track of the storm shifted farther east.
Projections as of Noon Monday
I’m posting this because Houston residents may have friends, relatives or travel plans in affected areas. See below.
Tropical storm force winds associated with Potential Tropical Cyclone 9 should arrive in the big bend area of the Florida panhandle sometime between Wednesday night and Thursday morning.
NHC predicts a 50:50 chance for tropical storm force winds extending north into Georgia.
The National Weather Service has this to say for people in the Panhandle and southern Georgia, “There is a potential for significant storm surge; heavy rainfall and flooding; and strong winds across the north and eastern Gulf Coast.”
“Impacts could begin as early as Wednesday night and last into Friday,” says NWS. “More detailed and specific impacts will be highly dependent on future track/intensity and we’ll be including those in future updates in the next day or two.”
Frequency of Major Hurricanes
When/if the Potential Tropical Cyclone 9 reaches 39 MPH, NHC will dub it Helene.
We’ve already had one major hurricane in the Gulf this year – Beryl. The second major hurricane usually develops in the Atlantic Basin by September 19. So, even though this season has fewer than normal named storms, it will have an average number of major hurricanes for this part of the season if Helene becomes a Category 3 or higher.
Current Status
At present, NHC says the area of concern in the northwestern Caribbean between Honduras and Cuba continues to produce disorganized showers and thunderstorms. Some mid-level rotation is evident in visible satellite images.
A gradual turn toward the northwest is expected during the next day or so. Models agree that the center of the system should reach the northeast Gulf on Thursday.
Since the disturbance currently lacks a well-defined center, future track adjustments may be required. Given the large size of the tropical-storm-force wind field and fast forward speed that is forecast, storm surge, wind, and rainfall impacts will likely extend well away from the center, particularly to the east of the system.
While the system is currently broad and not well organized, the models suggest a more well-defined center should develop during the next day or so.
Once the system becomes better organized and develops an inner core, the environmental and oceanic conditions appear favorable for significant strengthening. The sea surface temperature anomaly chart below shows that temperatures in the Caribbean and Gulf are up to 8 degrees Fahrenheit warmer than average for this time of year.
An Air Force Reserve reconnaissance aircraft will investigate the system this afternoon.
Tropical Storm Warnings and Hurricane Watches have already been issued for portions of western Cuba and the Yucatan Peninsula of Mexico.
Key Messages
Posted by Bob Rehak on 9/23/24
2582 Days since Hurricane Harvey
Potential New Tropical System Headed Toward Central Gulf
9/22/2024 at 6PM – The National Hurricane Center (NHC) issued a 2PM update today that warns of an 80% chance of a potential new tropical system forming in the seven days. They give the new tropical system a 40% chance in the next two days. The system is now centered in the northwestern Caribbean between Honduras and Cuba.
However, NHC predicts the storm will track somewhere between New Orleans and the Florida Panhandle. While it is no immediate threat to Texas, residents should keep an eye on developments in the next few days, they say.
NHC Graphics
Favorable Environmental Conditions
NHC predicts the track will bend east after crossing between the Yucatan and the western tip of Cuba.
“Disorganized showers and thunderstorms located over the northwestern Caribbean Sea and portions of Central America are associated with a broad area of low pressure,” they say. “Environmental conditions appear favorable for development of this system, and a tropical depression or tropical storm is likely to form during the next few days…”
Regardless of development, this disturbance will produce heavy rains over portions of Central America during the next several days. Interests in the northwestern Caribbean, Yucatan Peninsula, and western Cuba should closely monitor the progress of this feature.
Later this week, the system should move generally northward across the Gulf of Mexico, and “interests along the northern and northeastern Gulf Coast should also monitor the progress of this system.”
Local Impacts Seen as Limited As of Now
Jeff Lindner, Harris County’s meteorologist, said, “The system should lift northward over the Gulf of Mexico by mid to late week. A large upper level low over the southern plains will help draw the tropical system north of northeast toward the US Gulf coast.”
Lindner added that most models are in agreement at this point which makes confidence fairly high. However, he also said, “There may be some small differences in the ultimate track toward the US Gulf coast.”
He concluded, “Guidance also suggests this will be a large tropical system which is capable of moving huge amounts of water in the Gulf.”
“With the current higher than normal fall lunar tides in place, there is some potential for elevated tides along the Texas coast late this week, even for a tropical system passing well to our east.”
Year-to-Date Hurricane Season Behind Average
So far, we have had seven named storms this year:
If this system turns into a named storm, it will become Helene.
Everyone predicted a severe hurricane season this year, but so far, it has not materialized. On average, we have our tenth named storm by now. See below.
All last week, forecasters warned that this storm had a chance of development. And on most days, the chances increased. Keep your eye on this one!
Posted by Bob Rehak on 9/22/24
2581 Days since Hurricane Harvey