Life-threatening heat today in Puerto Rico so hot that some meteorologists are astonished. And more of the same to come this week. Heat index numbers as high as 115-125 today!! So what is going on? There are many factors, so let's dig in... thread 1/
A pocket of Saharan dust is right over the island, leading to clear weather, helping boost temperatures. But there's a lot more....
Zoom out and we see a culprit. A large/ intense high (heat dome) forming just east of Puerto Rico, unusually far south, leading to a SE flow and drawing up high humidity. But also record warm Tropical Atlantic water temperatures helping boost dewpoints...
Yes the warm water is partially due to climate change, so it is a factor. Tropical ocean temps have warmed by ~2F. Also the natural distribution of "anomalously" warm water this year favors the tropics. Last summer it favored the North Atlantic... but there's more...
Now we arrive at the Wavy jet stream. The pattern right now is ludicrous in/ around North America. Blocky is an understatement. Some may be due to Typhoon Mawar's added wave breaking energy. But we are seeing these blocks more often especially during spring/ summer...
There's a lot of work being done to figure out the link between climate change, blocks and the wavy jet. The loss of sea ice and uneven heating at the poles is likely a factor in high latitude blocks. This leads to a very amplified pattern, big blocky lows and heat domes...
Next, we have a developing El Nino adding tons of energy to the mix. The subtropical jet is screaming, but that is more of a winter time phenomena than summertime for El Nino. With that said, when you overlay that on the prevailing pattern I can only surmise it amplifies...
The bottom line: As we go deeper into 2023 and El Nino intensifies, we should expect a stunning year of global extremes which boggle the meteorological mind. The base climate has heated due to greenhouse warming and a strong El Nino will push us to limits we have yet to observe.
@MichaelEMann did some work on Quasi Resonant Amplification. Summer is favored. But you'll have to ask him if this could be a case of that? science.org/doi/10.1126/sc…
As you may suspect both the dewpoint in FL (surface moisture) and more importantly the precipitable water (total column moisture) in June have been trending up.
For every 1F increase in temperature, the column can hold 4% more moisture. We have warmed ~3F since pre-industrial 1/
Wow now have the capacity for ~12% more moisture. Thus the capacity to fuel more frequent/intense rain. In some cases more moisture means more instability, thus stronger storms & rain rates. Per @MWehner2005 CC spiked Harvey by up to 38%, w/ CC's share of the damage $13B 2/
@MWehner2005 The Gulf is record warm because: the baseline has been warmed by climate change - and- the historic heat dome over Mexico & the Gulf which made for hot/ cloud free weather. The Gulf is a big player in dewpoint and also rainfall rates, a likely contrubuter to FL's extreme rains 3/
25,000 years ago this is how Florida’s coastline looked. Sea level was 427 ft lower with all the water locked up in miles-thick ice at the peak of the last ice age. If you lived in Tampa you’d needed to walk 100 miles W to go to the beach. Follow along on this very educational🧵
This is what it looked like at the last glacial maximum. Ice spread all the way down to NYC and Chicago. If you go to Central Park in NYC you can see the edge of where they ended, there are huge boulders there. These ice ages have occurred every ~100K years recently. Here’s why…
Earth’s tilt, orbit and wobble change on the order of 10s of 1000s of yrs. Milankovitch Cycles. This changes amount of solar radiation received and where the sunlight hits, gradually changing Earth’s avg temp over 1000s of years, leading to ice ages and warm periods. Here’s…
This image is astonishing for both the message it communicates and for its sci comm value. Incredible work by team @CopernicusEU
It shows global ocean temps for each year since 1940. The alarming, yet brilliant part is the pink shading which highlights the 2023-2024 jump 1/
From 2023-2024 all areas in deep red were record warm. A huge area.
In May 2024 that record hot area was ~25%, so 1/4 of our planet. Huge amount. 2/
The avg global temp of the past 12 months was 1.63 above pre-industrial levels (~3 degrees F).
IPCC says this warming is 100% due to humans unequivocally.
While this spike above the Paris goal of 1.5C maybe be temporary (that is to be seen), we are super close to exceeding it 3/
Putting aside the Gulf Loop Current, speaking more generally about warming water, in a perfect environment (moist, low shear) for every 3F of sea sfc warming, a strong hurricane’s wind speeds can inc. 20%. So a 150 mph storm, can grow to 180mph storm, and damage pot. ⬆️ 67% 1/
Sea sfc temps across the Gulf & Carib are ~3F warmer than a few decades ago. That’s one reason we should care about a warming world.
The example I use is based on an already strong hurricane in a nurturing environment, but it can happen. Source for calc: michaelmann.net/sites/default/…
Notice the destructive potential increases exponentially as winds increase. According to Mann’s paper a 1C boost yields 12% wind boost and 40% potential damage boost.
A strong storm one category more intense (all other things being equal) can more than double the damage. 3/
“The climate always changes”… that’s true. Over tens of thousands of years Earth’s tilt changes a bit and so does Earth’s orbit around the sun… sometimes closer to a circle, sometimes an ellipse. This changes the amount of sunlight Earth receives and thus Earth’s avg temp 🧵 1/
As a result of orbital changes, every ~100,000 years the Earth sees an ice age. In between - where we are now - are warm periods called interglacials. Notice the difference is only 10 degrees F!
Those changes are natural and generally gradual.
But a century ago that changed 2/
Global average temps have been fairly stable over the past 10K years, with some regional cool and warm periods. But in the past several decades temps spiked (red on right) at a rate >10X the natural rate of anything we’ve seen in millions of years. 3/
The science behind this weekend’s 265 mph jet stream! A trans Atlantic flight reached an astonishing 835 mph. So Lets talk about meteorology, how climate change factors in and not breaking the sound barrier… 🧵 1/
The reason: two jets converge into 1 over the US and a sharp contrast of frigid vs warm air enhance the wind.
The result: a 265 mph upper level jet helps boost a Newark to Lisbon flight to peak speed of 835 mph reaching Lisbon in 5:44…. About an hour faster than normal! 2/
Odd that this story has repeat a few times in the last few years, record flight speeds? Climate change? Recent paper found that for every +1C in temp = 2% inc. in jetstream speed (plus 2.5X for fastest winds). We are at +2C now so that’s 10% boost. Roughly 240 becomes 275 mph 3/