Isaac And A Few Hurricane Facts

Stay up to date with the latest information on Isaac via the National Hurricane Center's website.

Below is a 4-Day rainfall graphic ending at 10 am CDT Thursday, August 30, 2012.  Interesting rain totals in the area around New Orleans over to Mobile, AL.  Click on image for larger version.

Isaac Rainfall

You can generate rainfall graphics like the one above by clicking here and here.

See the Saffir-Simpson Hurricane Wind Scale to learn what the different hurricane categories mean.

See our Weather-Ready page if you are interested in hurricane preparedness information.

Listed below is some information about recent hurricanes and tropical storms:   

1) When was the last time the remnants of a tropical cyclone affected southern Wisconsin?

Heavy rains of 1-3" soaked south central and southeast Wisconsin on September 4th and 5th of 2008.  The rain was associated with the remnants of Hurricane Gustav, which had made landfall in Louisiana as a category 2 hurricane on September 1, 2008.  The heavy rain affected parts of Jefferson, Waukesha, Milwaukee, Rock, Walworth, Racine, and Kenosha Counties.  Ponding of water on roads and in other low spots was reported in many locations.

Then, for a second time in one month, the remnants of a hurricane brought rainfall to Wisconsin.  Between September 13th and 14th of 2008 the remnants of Hurricane Ike affected south central and southeast Wisconsin.  Hurricane Ike had made landfall near Galveston, TX as a strong category 2 hurricane early in the morning on September 13th and was noted for its large diameter, which nearly encompassed the entire Gulf of Mexico! Rainfall amounts from Ike's remnants were not as large though and ranged from less than 0.10" northwest of Madison to 0.50-0.75" over the far southeast corner of Wisconsin.

However, Ike came on the heels of several other low pressure systems that moved northeast along a stalled frontal boundary, over southern Wisconsin and northern Illinois. Around 1.0-2.5" of rainfall occurred south of a line from Madison to Milwaukee.  Farther north, rainfall was lighter, generally from 0.30-0.75".

Hurricane Ike before landfall is shown in the image below.  Click on image for larger version.


Below is a graphic showing the paths of the remnant low pressures associated with Gustav (#7) and Ike (#9) through parts of Illinois, Indiana, and Michigan.  Click on image for larger version.

Gustav Ike Paths

You can view information and paths of tropical systems in the Atlantic Ocean area going back to 1995 on the National Hurricane Center's web site here.


2) What was the last tropical storm or Hurricane that made landfall in the US?


The most recent Tropical Storm or Hurricane to make landfall on the U.S. mainland prior to Isaac was Tropical Storm Lee on September 4, 2011 near Lafayette, LA. While the storm only had around 46 mph winds, its slow forward motion allowed it to dump over 15" of rain in Holden, LA. Afterward, the remnants of Lee drifted northeast and went as far north as Binghamton, NY, leaving high rainfall totals and flooding in its wake. For more information about Tropical Storm Lee, click here. 

3) What was the last hurricane that made landfall in the US?

The most recent hurricane to make landfall on the U.S. mainland prior to Isaac was Hurricane Irene.  Irene was also the first landfalling U.S. hurricane since 2008. The storm made landfall in Puerto Rico as a tropical storm, but was quickly upgraded to a category 1 hurricane.  From there, Irene made its way towards the Outer Banks of North Carolina, making landfall near Cape Lookout, NC on August 27, 2011 as a category 1 hurricane with up to 92 mph winds.  As much as 8.5 feet of storm surge was reported, along with 20" of rain, and 27 foot waves.  Irene then continued up the east coast, making landfall again in New Jersey and Brooklyn, causing significant flooding. In the end, Hurricane Irene was ranked among the top 10 costliest disasters in US history.  For more information about Hurricane Irene, click here.

See Irene's track below.  Click on image for larger version.

Irene Track 

Saffir-Simpson Color Scale Legend  

4) What was the last major hurricane (category 3 or higher) that made landfall in the US?

The last major hurricane to hit the U.S. mainland was Hurricane Wilma.  After developing in the western Caribbean Sea and moving over the Yucatan Peninsula, Wilma made a sharp turn towards the northeast and made landfall near Naples, FL on the morning October 24, 2005 as a strong category 3 storm, with 125 mph winds.  Prior to making landfall in Florida, Wilma had reached category 5 status over the Caribbean Sea, with winds as high as 175 mph and a minimum low pressure of 882 mb, making it the most intense hurricane on record in the Atlantic.  Wilma was a fast moving storm, which helped ameliorate the amount of damage that could have occurred in Florida.  However, storm surge did engulf parts of the Keys and rainfall amounts as high as 9" were reported in Florida.  Incredibly, an island off the coast of Cancun, Isla Mujeres, reported 68" of rain in 42 hours! For more information about Hurricane Wilma, click here.

Also worth noting, as of August 30, 2012, it has been a record 2,502 days since a major hurricane hit the US.

The image below shows Hurricane Wilma at its peak on October 19, 2005.  Click on image for larger version.


5) What about Hurricane Katrina?

Hurricane Katrina made landfall in south Florida on August 25, 2005 as a category 1 hurricane with winds as high as 80 mph and rainfall totals over 15" in some locations. After skimming the southern tip of Florida, Katrina moved west over the Gulf of Mexico and became a major hurricane on August 26th. Katrina began to move northward and became a category 5 hurricane with winds as high as 170 mph and a minimum pressure of 902 mb, the 4th lowest pressure recorded for an Atlantic storm. Before making landfall near Bures, LA on the morning of August 29th, Katrina weakened to a category 3 hurricane. It is suggested that the weakening was due to deterioration of the inner wall of the eye and entrainment of dry air into the western side of the storm. Landfalling wind speeds near Grand Isle, LA were around 125 mph with a minimum pressure of 920 mb, the 3rd lowest pressure recorded for a landfalling Atlantic storm in the US.

Winds ended up reaching as high as 140 mph in southeast Louisiana and rainfall amounts were generally around 8-10" along and east of Katrina's track. Mobile, AL, Biloxi, MS, and Gulfport, MS were inundated by as much as 20 to 30 feet of storm surge. In addition, as a result of Katrina, at least 80% of New Orleans was submerged underwater when levees surrounding the area failed. Some parts of New Orleans were under as much as 20 feet of water! For more information about Katrina, click here.

The image below shows Katrina's track.  Click on image for larger version.



NWS Milwaukee/Sullivan

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