
Tropical Storm Imelda formed,strengthened and made landfall in just an hour near the Texas coast Tuesday,but it's not the first tropical system to spin up quickly near the U.S.
Imelda originated from an upper-level low pressure system that dove southwestward off the coast of the Carolinas last week into the Gulf of Mexico early this week,as this spectacular satellite loop from Weather Now 24 senior meteorologist Stu Ostro shows.
The National Hurricane Center highlighted the western Gulf of Mexico for potential development on early Saturday morning,but the chances for development remained low through Tuesday at 8 a.m. CDT.
That is,until the system quickly became more organized on Tuesday,with increasing thunderstorms bubbling just off the Texas coast.
A tropical depression formed at 12 p.m. CDT Tuesday. It was forecast to become a tropical storm and a tropical storm warning was issued for part of the Texas coast.
But it only took 45 minutes for that to happen.
Tropical Storm Imelda formed at 1245 p.m. CDT,bringing with it a sustained wind of 40 mph at Freeport,Texas.
Imelda made landfall at Freeport 15 minutes later,at 1 p.m. CDT,just an hour after first being designated a tropical depression.
Since Imelda moved over land shortly after developing,it was not able to strengthen,but heavy rainfall and flooding were always the primary concern with this system.
(MORE:Imelda Forecast)
Other Tropical Systems That Developed Quickly Near the U.S.
Changes with the system that became Imelda happened remarkably fast,but it is not the first system to develop quickly near the U.S.

Tropical Storm Emily did the same in 2017. A tropical depression formed on July 30 in the eastern Gulf of Mexico along an old cold front and a few hours later it became Tropical Storm Emily.
Emily then made landfall near Longboat Key,Florida,on the morning of July 31. Heavy rain and flooding occurred and total damage was estimated around $10 million.
2007's Hurricane Humberto also developed rapidly near the Texas coast after forming from an old front in the Gulf of Mexico. A tropical depression organized about 120 miles south of Galveston,Texas,on September 12 and became a tropical storm three hours later.
This small tropical cyclone rapidly intensified and made landfall as a Category 1 hurricane near High Island,Texas,early on September 13.
In 2001,Tropical Storm Allison also developed quickly and brought extreme rainfall and flooding to portions of southeastern Texas. It caused $9 billion in damage and 41 deaths. Allison was so destructive the name was retired,a rare occurrence for a tropical storm.

Allison originated from a tropical wave that moved off the coast of Africa on May 21. However,this system was not able to organize until the morning of June 5 when it became Tropical Storm Allison. It made landfall nine hours later near Freeport,Texas.
Allison lingered over Texas for several days,then moved back into the Gulf of Mexico. It was this slow movement that allowed copious amounts of rain to fall over the same area,prompting dangerous flooding,including in Houston.
In 1983,Hurricane Alicia also developed from an old front in the northern Gulf of Mexico after first becoming a tropical depression on the morning of August 15 about 160 miles south of New Orleans. It strengthened into a tropical storm six hours later.
Alicia stayed over water longer than Allison,Humberto,Emily or Imelda. It was a small tropical cyclone and was able to intensify into a Category 3 hurricane just 66 hours after becoming a tropical depression. Alicia made landfall on Galveston Island as a major hurricane on August 18. The storm caused $3 billion in damage and 21 deaths.
Michael and Harvey,two recent storms,are also worth mentioning here.
Hurricane Michael in 2018 rapidly developed and went from a tropical depression on October 4 to landfall as a Category 5 hurricane on October 10 near Mexico Beach Florida. However,most of the intensification of Michael occurred over the Gulf of Mexico,and it did not form near the U.S. coast.
In 2017,Hurricane Harvey first developed near the Lesser Antilles but then degenerated into a tropical wave. It was able to redevelop when it reached the Gulf of Mexico and it rapidly intensified into a major hurricane when it was near the coast of Texas before making landfall as a Category 4 hurricane near Rockport.