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Here's what causes extreme damage in hurricanes

CNN's Tom Foreman explains the damage storm surge from a category 4 hurricane could do.

Posted: Sep 12, 2018 11:25 PM
Updated: Sep 12, 2018 11:54 PM

The National Weather Service says almost half of all deaths from tropical cyclones come from storm surge.

While many people focus on the wind speed of storms, the danger often comes from the water flowing in from the ocean.

Privately, you may be wondering (and you wouldn't be alone): "What exactly is storm surge?"

"A storm surge is a rise in water level caused by a strong storm's wind pushing water on-shore," said CNN meteorologist Brandon Miller. "The wind literally piles up the ocean water and pushes it on the land."

Forecasters are worried about the surge from Hurricane Florence, which is expected to be a major storm when it pounds the Carolinas on Thursday and Friday.

The storm surge warning issued by the National Hurricane Center extends from the South Santee River in South Carolina to Duck, on North Carolina's barrier islands known as the Outer Banks.

Much of this part of the Eastern Seaboard is not very high at all and forecasters expect storm surge between the mouth of the Cape Fear River and Cape Lookout to be as high as 13 feet.

Geography, tide-cycle and wind direction are all factors in how severe storm surge could be, Miller said. The stronger the storm, the stronger the winds and the higher the storm surge will be.

Storm surge also can exacerbate flooding. As the water piles up along the coast, rivers and streams that typically drain into the ocean can become clogged farther upstream, forcing water levels to rise.

That water doesn't just leave. Depending on how much water was pushed ashore and the area's watershed, it may hang around, causing further damage to communities.

Due to climate change, storm surge has become an even greater threat in recent years.

"Sea levels have risen in most places by about 1 foot over the past century. The higher baseline ocean level allows storm surges to reach even higher, increasing their destructive capabilities," Miller said.

The National Weather Service in a 2014 report said that most surge deaths occurred in Hurricane Katrina and several other big, powerful storms. In a majority of storms, excessive rainfall that leads to drownings is the leading cause of death. Florence is expected to also be a rainmaker, with totals of 35 inches possible in some areas.

Mississippi Coronavirus Cases

Data is updated nightly.

Cases: 307519

Reported Deaths: 7096
CountyCasesDeaths
DeSoto20772248
Hinds19888408
Harrison17489302
Rankin13311275
Jackson13097243
Madison9895210
Lee9856169
Jones8290160
Forrest7523146
Lauderdale7187237
Lowndes6262144
Lamar610584
Lafayette6027117
Washington5280132
Bolivar4769129
Oktibbeha455297
Panola4442103
Pearl River4419139
Warren4280118
Marshall4273100
Pontotoc416472
Monroe4057132
Union403675
Neshoba3987176
Lincoln3869108
Hancock372085
Leflore3468124
Sunflower329389
Tate322681
Pike3180104
Scott310572
Yazoo304368
Alcorn297764
Itawamba296776
Copiah292965
Coahoma289677
Simpson287484
Tippah284668
Prentiss275659
Marion265779
Wayne261341
Leake261073
Grenada254982
Covington254580
Adams245882
Newton244859
George237847
Winston225981
Tishomingo222067
Jasper219748
Attala213273
Chickasaw204857
Holmes186471
Clay182454
Stone179131
Clarke176876
Tallahatchie175240
Calhoun163230
Yalobusha158836
Smith158534
Walthall130543
Greene129433
Lawrence126223
Noxubee125933
Montgomery125542
Perry125138
Carroll120826
Amite120041
Webster113432
Jefferson Davis105432
Tunica102525
Claiborne101330
Benton97225
Kemper95226
Humphreys94332
Franklin81823
Quitman78916
Choctaw72817
Jefferson64828
Wilkinson64727
Sharkey49617
Issaquena1686
Unassigned00

Alabama Coronavirus Cases

Cases: 518899

Reported Deaths: 10712
CountyCasesDeaths
Jefferson753641487
Mobile37763798
Madison33859494
Tuscaloosa25266443
Montgomery23962565
Shelby23106238
Baldwin20631300
Lee15524165
Calhoun14284311
Morgan14139268
Etowah13662345
Marshall11957219
Houston10380278
Elmore9993200
Limestone9811147
Cullman9470188
St. Clair9426234
Lauderdale9215227
DeKalb8746181
Talladega8058171
Walker7087275
Jackson6754110
Autauga6723103
Blount6483135
Colbert6203130
Coffee5399112
Dale4767110
Russell428838
Franklin419982
Chilton4083109
Covington4053114
Tallapoosa3893146
Escambia387674
Dallas3527149
Chambers3499122
Clarke346360
Marion3065100
Pike305875
Lawrence295395
Winston272372
Bibb256258
Marengo248661
Geneva245875
Pickens232959
Barbour224755
Hale218775
Butler212266
Fayette208960
Henry187844
Cherokee182044
Randolph176941
Monroe171440
Washington164038
Macon154548
Clay149354
Crenshaw149257
Cleburne146041
Lamar139234
Lowndes136453
Wilcox124327
Bullock121340
Conecuh109028
Perry107926
Sumter102932
Coosa99228
Greene90734
Choctaw58724
Out of AL00
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Hi: 86° Lo: 50°
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Columbus
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Oxford
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A cold front will move into our area during our Tuesday. This front will bring some chances for some rain and isolated thunderstorms for our Tuesday night. Some of the activity will linger in our area into our Wednesday.
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