Parts of the Gulf Coast are under a Hurricane Watch as Potential Tropical Cyclone Two is likely to become Tropical Storm Barry in the next 12-24 hours.
The National Hurricane Center has given this system a 100% chance of becoming a Tropical Storm and is likely to be upgraded during the next advisory. Hurricane Hunters are en-route to investigate the system tonight to determine if the system has become more organized and if maximum sustained winds of Tropical Storm force (39 mph) are being produced.
Currently the center of circulation is over open water about 115 miles southeast of the mouth of the Mississippi River. While over the warm waters of the Gulf of Mexico it can concentrate on strengthening and becoming more organized.
This system has been delivering heavy rain and thunderstorm activity to the Florida Panhandle over the past couple of days as it slowly moved southward and out into the Gulf. The west coast of Florida will be experiencing the extreme outer bands of this system for tonight which could produce heavy rainfall and a few tornadoes, particularly waterspouts, common for the state of Florida with tropical cyclone activity. However, Florida is not the main area of concern at this time. Western states bordering the Gulf of Mexico, especially Louisiana, should be on high alert for this storm.
Mississippi and Louisiana have already been receiving heavy amounts of rain from the western side of this system as it continues to strengthen and develop. This morning many residents in New Orleans woke up to flooded roadways and heavy rains. Lines of thunderstorms associated with the extreme outerbands of the system ranged far out into the Gulf and battered New Orleans, where as much as 7 inches (18 centimeters) of rain fell over a three-hour period Wednesday morning.
Heavy rain will continue as this storm becomes more organized. As Potential Tropical Cyclone Two meanders over the open waters convection will continue producing more clouds and therefore more thunderstorm activity. Clouds will continue to accumulate not only on the western side of the storm (currently affecting Mississippi and Louisiana) but also on the drier east side of the storm, which will affect the coastlines of Alabama and extreme west parts of the Florida Panhandle.
At this time, the main threat with this system will be the rainfall. While over the Gulf of Mexico gaining strength it will continue to hug very close to the coastlines delivering heavy rainfall until this weekend, when it is expected to turn northward and impact land. These forecasts will indeed change over the next few days as this system strengthens and we determine if it will move and track close to land (which could help to weaken the storm) or if it will stay far offshore which could aid in strengthening the storm even further. At this time parts of Louisiana can expect a total of between 15 to 20 inches of rain between today, July 10 and next Wednesday, July 17. Isolated areas could see values in excess of 25 inches of rain.
Tropical Storm Watches and Warnings are up along the coastlines of Louisiana along with a Storm Surge Watch. These are likely to be upgraded to Warnings once the system has been deemed a Tropical Storm.
This storm system is moving fairly slowly at about 8 mph to the WSW. The speed and direction will play a key role in whether this storm rapidly intensifies. First, the slower a storm moves, the longer it has to intensify and take advantage of those warm SSTs, which are prime for development at this time (over 80°F). Additionally, coastlines will be enduring the effects for a longer period of time which will increase the flooding and storm surge threat.
Second, the direction Potential Tropical Cyclone Two is moving: WSW. That southerly direction is pushing the storm further away from land and out into open water. Land interaction helps to weaken a tropical system and prevents it from intensifying. If this storm continues out to sea and away from land there will be a higher chance that this system will rapidly intensify and possibly become a hurricane.
At this time, the National Hurricane Center is forecasting that the system will become a Tropical Storm, and adopt the name Barry, by Thursday (likely could become a Tropical Storm by late tonight). This will make it the second named tropical cyclone of the 2019 Atlantic Hurricane Season.
At this time it will continue to stay over the open waters of the Gulf until Saturday before approaching the shores of western Louisiana and eastern Texas, and it could very well be a hurricane at the time of landfall.
Most models are in agreement that this soon-to-be Tropical Storm will stay offshore for a few days before interacting with a high pressure system lingering just off the Texas coastline. This high pressure will block this storm from continuing westward into Texas and instead curve the storm northward into the state of Louisiana..
Louisiana is not the only state that will be affected by this storm. Mississippi, Alabama and Florida have already seen heavy amounts of rain from this system and will continue to accumulate more moisture over the next few days, especially Mississippi.
Extreme portions of east Texas should also be concerned with this system. True, the high pressure system is acting as a shield and preventing the storm from traveling into most of Texas but parts of extreme east Texas will see some impacts. If this storm impact the far west side of Louisiana, Texas could receive heavy rains and flash flooding. Additionally, once this storm impacts land and moves inland it will likely undergo extratropical transition which will increase the size of the system as a whole as it transforms. When this occurs the rain area expands and will bring additional heavy rain to the Gulf States and even places like Arkansas and Tennessee. Texas and Oklahoma will also experience heavy winds since the winds generally shift to the west side of a tropical system as it undergoes extratropical transition, while the rain shifts eastward.
Louisiana Gov. John Bel Edwards has already declared a state of emergency Wednesday for all of Louisiana because of the possibility of flooding, winds, and storm surge throughout the state.
“There could be a considerable amount of overtopping of Mississippi River levees in Plaquemines Parish on both the east bank and the west bank,” Edwards said at a Wednesday news conference.
He ordered the Louisiana National Guard to begin deploying soldiers and high-water vehicles to the state’s most vulnerable areas.
Torrential rain up to 18 inches of rain is possible and some areas could even receive isolated values exceeding 20 – 30 inches. At this time the heavy rains are the main threat with this system. Once strengthening takes place with the potential for a hurricane forming, storm surge will then become the next main threat to coastlines.