3 ms·

How does this 20" of rain compare to Katrina? https://svs.gsfc.nasa.gov/3221 https://svs.gsfc.nasa.gov/3221

jeffbee 5y ago
I don't know but the scale of that viz only goes to 80mm, which is only 3 inches. The forecast for the river in New Orleans suggest no flooding this week. https://water.weather.gov/ahps2/hydrograph.php?wfo=lix&gage=norl1 https://water.weather.gov/ahps2/hydrograph.php?wfo=lix&gage=...
dredmorbius 5y ago
Hurricane Katrina saw 15" of rain over New Orleans in 2005, though a higher storm surge was measured (14') than what is predicted for Ida (7--11'). https://en.wikipedia.org/wiki/Hurricane_Katrina https://en.wikipedia.org/wiki/Hurricane_Katrina http://www.nhc.noaa.gov/data/tcr/AL122005_Katrina.pdf http://www.nhc.noaa.gov/data/tcr/AL122005_Katrina.pdf [pdf] There are multiple factors that come into play. There's storm surge and tides. Tides around Morgan City are pretty modest (less than 1/2 foot / 15cm total range), and will be low as the storm arrives. Storm surge forcast is 7-11 ft per NOAA. Given the extreme low-lying land, that's significant. I don't have comparative numbers for Katrina offhand. The total rainfall amount is one. The period of time over which it falls, and where the storm goes afterward are also critical. Ida looks to be slow-moving, and is presently slated to track pretty much directly up the Mississippi river, then over the Ohio River Valley. That means there's going to be heavy river flow coming downstream possibly for several weeks after the storm itself passes. I'd predicted and observed a similar trend when Hurricane Florence hit Wilmington, NC, in 2018, and upstream-based water flows contributed to flooding, and issues such as hog farm sludge empoundments (basically: pig shit lakes) in the region. For Louisiana, the concern is probably more petroleum refining and chemical plants. Note that Florence hung around for days. Ida looks as if it will stick around Southern Louisiana for about 18 hours, then start accelerating to the NNE, though remaining over the drainage baisin feeding into New Orleans.

I don't know but the scale of that viz only goes to 80mm, which is only 3 inches. The forecast for the river in New Orleans suggest no flooding this week. https://water.weather.gov/ahps2/hydrograph.php?wfo=lix&gage=norl1 https://water.weather.gov/ahps2/hydrograph.php?wfo=lix&gage=...

dredmorbius 5y ago

Hurricane Katrina saw 15" of rain over New Orleans in 2005, though a higher storm surge was measured (14') than what is predicted for Ida (7--11'). https://en.wikipedia.org/wiki/Hurricane_Katrina https://en.wikipedia.org/wiki/Hurricane_Katrina http://www.nhc.noaa.gov/data/tcr/AL122005_Katrina.pdf http://www.nhc.noaa.gov/data/tcr/AL122005_Katrina.pdf [pdf] There are multiple factors that come into play. There's storm surge and tides. Tides around Morgan City are pretty modest (less than 1/2 foot / 15cm total range), and will be low as the storm arrives. Storm surge forcast is 7-11 ft per NOAA. Given the extreme low-lying land, that's significant. I don't have comparative numbers for Katrina offhand. The total rainfall amount is one. The period of time over which it falls, and where the storm goes afterward are also critical. Ida looks to be slow-moving, and is presently slated to track pretty much directly up the Mississippi river, then over the Ohio River Valley. That means there's going to be heavy river flow coming downstream possibly for several weeks after the storm itself passes. I'd predicted and observed a similar trend when Hurricane Florence hit Wilmington, NC, in 2018, and upstream-based water flows contributed to flooding, and issues such as hog farm sludge empoundments (basically: pig shit lakes) in the region. For Louisiana, the concern is probably more petroleum refining and chemical plants. Note that Florence hung around for days. Ida looks as if it will stick around Southern Louisiana for about 18 hours, then start accelerating to the NNE, though remaining over the drainage baisin feeding into New Orleans.