Tropical Storm Barry forms: Up to 2 feet of rain to deluge Gulf states
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Tropical Storm Barry has formed and is expected to strengthen into a hurricane before making landfall with life-threatening flooding and damaging winds in some places.
Barry will remain over the warm waters of the Gulf of Mexico long enough to gather enough moisture for heavy rain, enrage seas and whip up high winds. It could dump as much as two feet of rain in some places. The storm prompted Louisiana Governor John Bel Edwards to declare a state of emergency on Wednesday, which he announced in a post on Twitter.
On Wednesday, the National Hurricane Center issued a hurricane watch for most of the coast of Louisiana.
"Barry will become a hurricane prior to making landfall on Saturday," AccuWeather Hurricane Expert Dan Kottlowski said.
Water temperatures in the northern Gulf of Mexico are in the middle to upper 80s F.
"Right now, our greatest concern is for torrential rain that would result in life-threatening flooding," Kottlowski said.
For that reason AccuWeather is initially designating this a level 2 storm on its RealImpact™ Scale for Hurricanes. The scale ranges from less than 1 to a 5 with 5 having the most severe impact.
Infrared GOES-EAST satellite image from early Thursday, July 11, 2019. (Image/NOAA/CIRA.)
The level 2 designation is based primarily on the amount of flooding that may arise over a broad area due to a general 10-18 inches of rain and an AccuWeather StormMax™ of 24 inches. The storm is forecast to peak as a Category 1 hurricane based on the Saffir-Simpson scale with maximum sustained winds of 75-95 mph with a storm surge of 3-6 feet. The Saffir-Simpson scale rates a hurricane solely on the strength of sustained winds.
AccuWeather created the RealImpact™ Scale for Hurricanes to assist with public safety and understanding, as well as risk of damage should a tropical threat arise.
"If the scale was retroactively used, Tropical Storm Allison would have a RealImpact of 4 and Harvey would have a RealImpact of 5, based primarily on flooding rainfall," Kottlowski said, referring to notorious storms that hit Texas in 2001 and 2017, respectively.
There is a chance that the storm reaches Category 2 on the Saffir-Simpson scale with maximum sustained winds of 96-110 mph just before landfall.
Officials in New Orleans are monitoring for any potential storm surge impacts near the mouth of the Mississippi River.
"The city is protected to a project height of 20 feet. There is still a great deal of uncertainty regarding potential impacts, so please continue to monitor the forecast over the next several days for the latest information," the National Weather Service in New Orleans said in a tweet. On Wednesday, as New Orleans was inundated with at least half a foot of rain, forecasts showed the river could crest at 20 feet, creating the possibility for a flooding disaster depending on the exact track the storm ends up taking.
People in coastal areas near and east of landfall should be prepared to protect property from minor to moderate coastal flooding into this weekend.
"The heaviest rain is expected to fall on parts of Louisiana, Mississippi, western Tennessee, Arkansas, and northeastern Texas," Kottlowski said.
Southeastern Texas may also receive heavy rainfall, but only if the storm were to move ashore along the western Gulf coast.
Enough rain is expected to fall to produce everything from street and highway flooding to small stream, bayou and river flooding.
Even though most rivers do not drain into the Mississippi River over the lower portion of its basin, some levels on the Mississippi remain high due to upstream runoff from this spring.
At Baton Rouge, Louisiana, the river has been at major flood stages for months. With the amount of rain anticipated to fall, flooding of some secondary rivers in the region is likely.
A track of the storm center into south-central Louisiana may bring relatively little rain to much of southeastern Texas. AccuWeather meteorologists are favoring this track at this time.
However, a storm track into the middle part of the Texas could produce tremendous rainfall in the Houston and Port Arthur, Texas, areas.
Storm surge may become a significant problem
Even a slow-moving tropical storm, on its eastern side, which typically carries the heavier precipitation amounts, can pump a significant amount of water northward from the Gulf of Mexico as a storm surge.
The stronger the large system becomes before landfall, the greater the risk of a significant storm surge near and north and east of the center of the storm.
"Another concern is for wind associated with the storm," Kottlowski said.
How strong the feature becomes will determine the strength of the wind. However, there is potential for the system to become a hurricane should it remain offshore into Saturday. For now, damaging winds are only anticipated to occur in a small area with this storm.
Even in lieu of a hurricane, sometimes tropical storms that are near the coast or make landfall can unleash sudden tornadoes. Some of the tornadoes can be wrapped in rain and difficult to see until the storm is already upon a neighborhood.
A tropical depression, tropical storm or minimal hurricane is likely to have little to no impact on operations of offshore oil and gas rigs.
A major hurricane in these areas could significantly impact production. Most offshore oil and gas rigs in the Gulf of Mexico are in the north-central and western portion of the basin.
Some offshore oil operators in the Gulf of Mexico have evacuated platforms and rigs ahead of the storm, KATC reports.
Four of the largest oil refineries in the world, based on processing capacity, are located in Louisiana and Texas.
Bathers and boaters beware
Regardless of the strength of the storm prior to landfall, rip currents, seas and surf will build throughout the Gulf of Mexico for the remainder of this week and into the weekend.
Squalls will intensify in the eastern Gulf and begin to propagate westward with the movement of the storm.
Waterspouts can be spawned in some of the squalls over the Gulf.
Kottlowski has been warning since early April that the Gulf of Mexico as well as areas east of Bermuda and off the southeastern coast of the U.S. need to be watched closely for early season development due to water temperatures running above normal.
While El Niño conditions may suppress the numbers of tropical storms and hurricanes in the Atlantic basin somewhat this year, all it takes is for one or two hurricanes to strike populated areas and result in great risk to lives and property.
July hurricanes rare in Gulf of Mexico
July is typically a slow month in terms of tropical activity. If this storm makes landfall in Louisiana as a hurricane, it will be only the fourth time since 1851 that a hurricane has made landfall in the state in July, according to AccuWeather Meteorologist Jesse Ferrell. Bob in 1979, Danny in 1997 and Cindy in 2005 all made landfall along the Louisiana coast.
Furthermore, no hurricane has formed in the Gulf of Mexico in July and hit the U.S. since Danny made landfall in southeastern Louisiana in 1997.
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