I am always careful when writing this type of piece because there is usually some contrarian hanging out on Twitter waiting to pounce on statements like “It’s the ______est year ever.” To avoid cliche trolling, it is important to use the word “on record.” With that out of the way, let’s discuss the U.S. experiencing its wettest 12-month stretch on record (in this case 1895 to 2019). Deke Arndt, a climatologist at NOAA’s National Center for Environmental Information (NCEI), tweeted:
In case you missed it, the last 12 months (May ’18 through Apr ’19) is the wettest 12-month stretch on record for the US. A warmer world turns up the hydrology dial. When we are sent the bill for climate change, it comes in the context of our water.
Here are the meteorological and climatological reasons why this likely happened as well as further explanation of the last sentence of Arndt’s Tweet.
NOAA
The graphic [below] shows how abnormally it was in the U.S. from May 2018 to April 2019, particularly in the upper Midwest and the eastern U.S. By the way, if you live in the region shaded orange-brown, resist the urge to say “but it was drier where I live” so climate change is a hoax. Your local experience doesn’t define the global experience.
Before I discuss climate connections, it is important to discuss meteorological connections first. The inevitable “it has always rained” or “climate changes naturally” is lurking in someone’s head right now. My placeholder response is that grass on your lawn grows naturally too, but it you put fertilizer on the soil, it grows differently. I will provide a more robust discussion later in the article.
Several places, including Washington, D.C, broke records for wettest 12-month stretch. Jason Samenow wrote an outstanding article in the Washington Post Capital Weather Gang explaining the meteorological context for the period. I summarize Samenow’s key points:
• A persistently high-pressure pattern east of the U.S. transported Atlantic Ocean and Gulf of Mexico moisture into the eastern half of the country.
• Another persistently high-pressure pattern near Alaska allowed storm-tracks to be directed into the upper Midwest and East by the jet stream
• Possible jet stream modifications due to the emerging El Nino (warm central Pacific sea surface temperatures). ...
The Corps assembled a proposal for upgrading the system, but it came with the shocking price tag of nearly $28 million from the city. ..But then in March, floes from upriver ice jams tore through the levees exactly as predicted...Taken together, outlays may eventually cost double what it would have taken to upgrade the levee and viaduct—but now those expenditures will be drawn from FEMA and the Department of Transportation’s disaster funds, not a local bond issue.
And it would serve our best interests to recognize that what once were considered 100-year floods could, in fact, be ten- or 15- or 20-year floods now.
dohboi wrote:.......
https://www.accuweather.com/en/weather- ... s/70008778
Severe storms trigger flash flood emergency around New Orleans as much more rainfall looms
Ten Years After Katrina, New Orleans Protected From Future Floods
https://www.youtube.com/watch?v=H80EIi90HKg
..... now home to what will be one of the world's largest pumping stations. 'We'll be able to pump an Olympic size swimming pool full in five seconds. So it gives you an idea of the pumping capacity of this facility,' said Elton Lagasse, an at large council member of Jefferson Parish. The facility is expected to be completed in 2017. Right now, temporary pumps that were built after Katrina remain in place. Lagasse said the community is far more prepared for any future hurricanes. 'They have completely re-leveed this whole system, redone all of our pump stations,' said Lagasse. 'All of our pump stations now have back-up generators, they have safe houses where the pump operators will stay. They are 35 feet off the ground and can withstand 250 mile per hour winds. So we are in a much better position than we were before as far as hurricane protection and as far as flood protection.'
In 1861, Northern California became the focal point for two consecutive atmospheric rivers that surged into the Sierra Nevada, melting snow at disastrous rates. By 1862, a catastrophic flood swept through the Central Valley, augmented by two rainstorms, creating an inland sea that was 300 miles long and 60 miles wide.
It rained for 45 days straight, according to a film produced by the U.S. Geological Survey. Thousands of cattle drowned, and vineyards and homes were washed away. The state went bankrupt. The American River near Auburn rose 35 feet, submerging towns.
New Orleans faces a never-before-seen problem with Tropical Storm Barry
Tropical Storm Barry presents New Orleans with an unprecedented problem, according to the National Weather Service.
The Mississippi River, which is usually at 6 to 8 feet in midsummer in the Big Easy, is now at 16 feet, owing to record flooding that's taken place this year all along the waterway.
In the meantime, Barry is spinning away in the Gulf of Mexico, threatening a storm surge of 2 to 3 feet at the mouth of the river, said Jeffrey Graschel, a hydrologist with the weather service's Lower Mississippi River Forecast Center in Slidell, Louisiana.
The unusual confluence of factors adds up to a forecast that has the river cresting Saturday at 19 feet, a level not seen since February 1950 and about 2.3 feet shy of the record set in April 1922, the weather service said Thursday.
This is the first time we've had a tropical system with water levels on the river this high," he said.
The prediction is rattling the nerves of residents also concerned about the 10 inches of rain Barry could dump before it moves out, CNN senior meteorologist Dave Hennen said. That deluge would follow the 9 inches that fell Wednesday in New Orleans, flooding parts of the city. ....
https://www.cnn.com/2019/07/11/weather/ ... index.html
...Earlier this week, the New Orleans branch of the National Weather Service (NWS) forecast the Mississippi River to crest at 20 feet Friday night into Saturday.
Levees in New Orleans are able to protect the city from surges up to 20 feet, creating the possibility for a disaster ...
On Thursday, the river level forecast showed the river was expected to crest at 19 feet on Saturday, just below major flood stage...
...Some streets were inundated with as much as 3 to 4 feet of water...
June 2019
Wet conditions from July 2018 through June 2019 resulted in a new 12-month precipitation record in the U.S., with an average of 37.86 inches (7.90 inches above average), according to scientists at NOAA’s National Centers for Environmental Information.
The average precipitation for June was 3.30 inches (0.37of an inch above average), placing it in the upper third in the record books. Flooding conditions persisted along the central and Lower Mississippi, Missouri and Illinois rivers
In 2019 (as of July 9), there have been 6 weather and climate disaster events with losses exceeding $1 billion each across the United States. These events included 2 flooding events and 4 severe storm events. Overall, these events resulted in the deaths of 15 people and had significant economic effects on the areas impacted. The 1980–2018 annual average is 6.3 events (CPI-adjusted); the annual average for the most recent 5 years (2014–2018) is 12.6 events (CPI-adjusted).
A slow-moving, single stationary storm brought so much rain to Baltimore that several neighborhoods flooded in the city Tuesday evening.
Photos and videos from across social media showed what looked like a river running through the streets of Baltimore in Little Italy, Harbor East and Fells Point.
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