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How Imelda's Prolific Rain, Flooding Compares to Harvey in East Texas
Published: September 20, 2019
(Brett Adair/Live Storms Media)
Tropical Depression Imelda is pounding part of Texas with rainfall measured in feet, not inches, reminding some of the record-smashing rain from Hurricane Harvey two years ago.
Vidor, Texas, Police Chief Rod Carroll told The Weather Channel Thursday morning that flooding in the town was "worse during this storm than it was during Hurricane Harvey."
"We have many areas that are underwater that were not previously underwater," Carroll said, referring to Harvey's flooding in Vidor, about 85 miles east-northeast of downtown Houston.
That's a jarring statement.
While Imelda's flooding impacts may be worse than Harvey in some parts of Texas, Harvey was a $125-billion disaster, the nation's second-costliest tropical cyclone behind only Katrina, because of its massive flooding rainfall, storm surge and wind damage from its Category 4 landfall.
Here's how Harvey is similar to Imelda, but also how Harvey remains in a class by itself.
Harvey's Extreme Rainfall Footprint Was Much Larger
As early Thursday afternoon, an area from Montgomery County, north of downtown Houston, into Liberty, Chambers, Jefferson, Orange, southern Jasper and southern Newton counties was estimated to have picked up 20 inches or more from Imelda. Parts of Matagorda and southern Galveston counties also picked up over 20 inches of rain.
Estimated Imelda Rainfall Totals and Flood Reports
We estimate the area covered by at least 20 inches of rain from Imelda to be about 2,200 square miles.
According to an analysis by Shane Hubbard from the University of Wisconsin, Harvey's 20-inch-plus rainfall footprint was about 13 times larger than Imelda, a whopping 28,949 square miles. That's an area slightly smaller than the entire state of South Carolina.
(Shane Hubbard/CIMSS/University of Wisconsin)
Harvey's 40-inch-plus rainfall footprint covered more area than Imelda's 20-inch-plus area so far.
Rainfall Extremes From Harvey Were Off the Charts
The peak rainfall total from Imelda so far is 43.35 inches at North Fork Taylors Bayou in eastern Texas.
These totals are in excess of those peak totals measured in Harris County during the billion-dollar Tropical Storm Allison flood of 2001.
These totals also place Imelda in the five heaviest tropical cyclone rain events in the Lower 48 states.
That list is topped by Harvey.
"Harvey was the most significant tropical cyclone rain event in United States history, both in scope and peak rainfall amounts, since reliable rainfall records began around the 1880s," National Hurricane Center forecasters Eric Blake and David Zelinsky wrote in the NHC final report on Harvey.
Harvey crushed the all-time record rainfall total from any U.S. tropical cyclone, which had stood since since 1950. It wasn't just one station, but seven different locations shattered that 52-inch previous record, according to Blake. Two of these locations measured an incredible 60 inches of rain.
Blake tweeted that some radar rainfall estimates suggested areas near Beaumont and Port Arthur may have picked up 65 to 70 inches of rain during Harvey, but there were no gauges that measured that much.
Harvey Lingered Longer
Imelda quickly went from a tropical depression to a landfalling tropical storm in just one hour off the Texas coast on Sept. 17. It then drifted northward through Sept. 18 and 19.
(Data: National Hurricane Center)
Harvey stalled over Texas on Aug. 26, 2017, then meandered slowly near the Texas coast until finally moving inland in southwestern Louisiana on Aug. 30, remaining a named storm 117 hours after landfall, more than doubling the previous state record for Texas.
If Imelda lingered as long as Harvey, it's hard to fathom how even more catastrophic the flooding would be.
(Data: National Hurricane Center)
Some Déjà Vu
There were a few things we noticed with Imelda's flood that were eerily reminiscent of some things we saw during Harvey.
Flooding forced the evacuation of the KBMT-TV studios in Beaumont after water began seeping in.
KHOU-TV in Houston simulcasted for its sister station while the evacuation of the KBMT-TV studios took place.
Two years ago during Harvey, KHOU's studios were flooded.
One of the most unforgettable sights from Harvey was of a flooded Interstate 10 near Winnie, Texas, between Beaumont and Houston.
Both Imelda and Harvey were destructive flood events that will long be remembered in the history of southeastern Texas floods.
If there's any small solace that can be taken, at least Imelda's prolific rain isn't nearly as massive as Harvey's.
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