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…
Alert: #Milton may threaten #TampaBay midweek.
I’m not an alarmist, it takes a lot to get my attention. This has it. If Milton landfalls at or just north of Tampa Bay as a cat 2-3 hurricane, it means up to double #Helene storm surge. And extensive, long term power outages 1/
While the exact track/ intensity is to early to know, a hurricane traveling across the Gulf from the west/ WSW is a worst case scenario for, if it hits at or north of the mouth of Tampa Bay. The 1921 borderline Category 3 which hit Tarpon Springs pushed 10-12 ft of surge in 2/
If this still looks like a threat tomorrow, to whomever it still threatens, start taking actions. Top off hurricane supplies. Make/ discuss your family plans. Elevate your valuables if you are near the water. Prepare to evacuate if you are in an evacuation zone on Monday. 3/
New: 2 rapid attribution studies on the impact of climate change on Hurricane #Helene have just been released. The results are very significant, yet unsurprising.
Warmer air, warmer water = much heavier rainfall rates. First study: ~50% increase in rain in parts of NC/ GA!! 🧵
First from @MichaelFWehner, who is one of the World’s experts on the connection between climate warming and Tropical cyclones.
“…our best
estimate is that climate change caused over 50% more rainfall during Hurricane Helene in some
parts of Georgia and the Carolinas.” 2/
@MichaelFWehner “Furthermore, we estimate that the observed rainfall was
made up to 20 times more likely in these areas because of global warming.”
That’s study number 1. Now let’s discuss study number two…
3/
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/