Hurricane Ida traveled over very warm Gulf of Mexico, rapidly intensified & nearly became Category 5 prior to landfall in Louisiana.

Al Roker said Gulf waters were 3° to 5°F above average due to climate change & directly caused Ida's intensity.

I saw similar reporting that Gulf of Mexico sea-surface temperatures were ridiculously warm, 85°-90°F, and that's certainly true. But, the Gulf of Mexico on average is always that temperature in August (unless a previous hurricane mixes up cooler water from below).
The entire Gulf of Mexico ocean surface can support a major hurricane if it is given enough time over the ocean to intensify, and other wind shear, humidity factors are favorable. Obviously, the long history of Gulf hurricanes is a testament to what nature hath wrought.
So, what was special about late-August 2021? I was certainly curious b/c I did not see any data analysis in any media reporting, just expert testimony.

The ocean surface (SST) was at least 30°C for the "hurricane" and rapid intensification phase of Ida right up to the coast. ImageImage
Cooling effects of the previous Hurricane Grace are seen in the anomaly map (blue colors), while warmer than normal shelf waters extended from the Texas Bight to mouth of the Mississippi.
Longer 28-day average shows generally warmer than normal (~0.2°C) than previous 30-years. ImageImage
Next, I took the Gulf of Mexico as a domain & used last 40-years of SST data (satellite retrieval) from OISSTv2.1 and created this nice matrix:
August 2021 Gulf SST ranged from 29.8° to 30.1°C, and you can follow downward to see previous years e.g.
August 1997 29.5° to 30.5°C Image
The average of this entire matrix (1982-2021) ranges from 29.6°C to 29.7°C from August 1-31, which means Gulf of Mexico temperatures overall vary little on average during the entire month (climatology).

August 2021 temperatures = 29.9°C or 0.3°C above last 40-years average.
I've mentioned over the past days that the shallower shelf waters along Louisiana coastline are well mixed and very warm from surface to seafloor. A hurricane cannot mix up cooler waters from below if there isn't any.
Hurricane forecasters of yesteryear observed almost all Gulf landfalling hurricanes weakened, and dramatically so, upon nearing the coast, likely due to winds in outer circulation upwelling cooler water.
That went out the window with Harvey, Laura, Michael & now Ida.
The Rapid Intensification up until landfall (and interrupted eyewall replacement cycle) likely benefitted from the warm shelf waters at the surface, and any mixing would have been limited to Ida's fast forward motion. But that's just speculation. 🌀
The proximate boost to Hurricane Ida's intensity was the deep warm reservoir of ocean heat within the Gulf of Mexico Loop Current.

But until Ida worked out the organization kinks, it looked ragged and slowly intensified.

Then, it went over the Loop Current jet fuel ⛽ Image
But an extreme ocean heat potential anomaly isn't required for a Category 5. Check out Hurricane Michael's heat potential from October 2018 ... maybe 1/4 magnitude compared to Ida's loop current. Image

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More from @RyanMaue

16 Sep
Could Europe run out of gas?
“The short answer is, yes, this is a real risk"

Skyrocketing energy prices across Europe as millions can't afford to heat their homes.

Another cold winter due to climate change would entirely deplete gas supplies. 🌡️

apnews.com/article/europe…
Climate change including extreme weather e.g. polar vortex, hurricanes, and lack of wind have conspired to tighten gas supplies across the world.

This confluence of events will only get worse, and could be catastrophic in another extreme cold winter.

fortune.com/2021/09/16/sho…
Carbon fees also at an all-time high meaning climate policy makes it even more expensive and infeasible to backfill supply with dirty energy.

Europe is also highly dependent upon Russia for gas.

Market will see gas prices soar further during cold snap.

cnbc.com/2021/09/16/eur…
Read 5 tweets
15 Sep
The HQ of @Mailchimp is in Ponce City Market in Atlanta, the site of the old Sears, Roebuck and Co. Mail-Order Warehouse and Retail Store

The market is an amazing story of urban renewal, from Sears to a $10B technology startup.

The history is awesome:
poncecitymarket.com/history
@Mailchimp In the 1860s, Ponce De Leon Springs are popular attraction for Atlanta residents. Later in 1903, the site is turned into the "Coney Island of Atlanta" -- an amusement park.
@Mailchimp In 1907, the Ponce de Leon lake is drained to make way for a minor league baseball park, where the Atlanta Crackers play for decades, until moving to Atlanta Stadium in 1965.
Read 4 tweets
3 Sep
Putting on my historian hat 🎩

Turns out the "extreme rainfall" records being reported by NY Times might be neglecting paper records in existence prior especially prior to the 1940s.

e.g. August 12, 1926: 3.24"
timesmachine.nytimes.com/timesmachine/1…
"STORM RECORDS EXCEEDED" August 12, 1926

"The heavy downpour ... let loose upon the city and which probably broke all records for a similar period ... flooded subways, railroad tunnels, basements and streets ..."

"...bolts of lighting played a tattoo upon church steeples" (?)
July 28, 1913 RECORD RAINFALL FLOODS THE CITY

Sewer overflow swamps hotels

BACK GUSH FROM DRAINS 😲

Same infrastructure as today,. not built to withstand weather from 108-years ago 👇

Property Owners to Demand Relief from Inadequate Sewers

timesmachine.nytimes.com/timesmachine/1…
Read 14 tweets
2 Sep
There is a popular narrative being amplified by media outlets that recent extreme weather events are unpredictable, came out of no where, or were unexpected.

Actually, it's failed leadership to be ignorant of extreme weather & climate threats, and then use that as an excuse!
Former NYC Mayor Bloomberg was a disaster when it came to preparing for extreme weather especially blizzards.

This is in direct contrast to Mayor de Blasio who proactively got the plows running for his first major snowstorm in Jan 2014.

reuters.com/article/us-usa…
Mayor de Blasio declared a state of emergency right away, and activated all emergency resources.

He was also on the phone with local media at 11:15 PM ET.

Impressed with the NYC response to unprecedented rainfall from Hurricane Ida remnants.

newyork.cbslocal.com/video/5953751-…
Read 4 tweets
31 Aug
Initial forecast for Tropical Depression 9 (Ida) from NHC went with 95-knots (Category 2) maximum prior to landfall.

That is 1 knot under Category 3 major hurricane, and it was noted this intensity was conservative.

nhc.noaa.gov/archive/2021/a…? ImageImage
While we have a forecast track cone based upon historical errors (170 miles at 4 days) plopped on the map, there isn't a similar intensity uncertainty graphic that conveys information for intensity -- about 15 knots. Example would be 100-115 knots or Cat 3 or Cat 4.
Error trend: Image
The chart of average intensity errors shows last 30 years lumping all forecasts together. You could filter further by region, month, initial intensity, etc.
Intensity skill improvement has leveled off in past 10 years, or so. Image
Read 6 tweets
29 Aug
Just overheard "eyeball replacement cycle" 🧐
The intensity has thankfully leveled off at 130-knots - top end Category 4.
#HurricaneIda continues a recent trend of Gulf of Mexico storms that do not weaken approaching landfall instead blowing up to max intensity.
The Gulf of Mexico is always warm enough to develop a major hurricane in August, with warm eddies spinning and looping providing extra ocean heat content. But a major recent difference is top-to-bottom extreme warmth of shallower shelf waters along TX and LA coasts.
30°C+
There's the Gulf of Mexico "loop current" strategically located along the track of Hurricane Ida.

Random chance that Ida crossed it? Or some chicken and the egg here?
Read 4 tweets

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