Mona Hemmati

To the free world: now is the time to stand with the Iranian people. Speak up. Share their voices. Be their voice when they are silenced.

A freer Iran means a safer world.

#Iran

Millions of Iranians are risking their lives to demand freedom and an end to the brutality of the Islamic Republic.

13 days of courage. 13 days of resistance.

The regime’s response? Internet blackouts, repression, and killings.

#Iran #IranRevolution #IranProtests2026 #IranInternetShutdown

Save NCAR Field notes from New Orleans, where I and 20,000 colleagues learned that Trump intends to destroy the National Center for Atmospheric Research.

Some reflections after returning back from a conference at which I and 20,000 colleagues learned that the Trump administration intends to dismantle #NCAR. This outrage should not happen. deepconvection.substack.com/p/save-ncar

Heading to #AGU25 on this beautiful snowy morning in NYC ❄️ Looking forward to an exciting lineup of talks and catching up with colleagues.

*Busy* Monday for me at #AGU25

NH12B-05 11:12-11:22 Applying the Swiss Cheese Model to Wildfire Risk Management in the Built Environment

TH15B 6-7 Town Hall Hurricane Katrina 20 Year Later

then RUNNING to Atmos Science section Student/Early Career mixer to talk cat modeling 7-8:30

Really looking forward to your talk, Kelly!

2025 marked a major milestone with the operational debut of Google DeepMind’s AI-based hurricane model, publicly released in June. The model delivered strong performance in predicting storm track and intensity, and notably demonstrated significant skill in anticipating rapid intensification events.

* Three Category 5 storms: #Erin, #Humberto, and #Melissa — the second-highest number of Cat-5s ever observed in a single season.

Only one named storm (#Chantal) made U.S. landfall, and zero hurricanes — the first year since 2015.

Although the season produced only 13 named storms (below the climatological average), it was classified as "Above Normal" by NOAA definition, driven by the high Accumulated Cyclone Energy (ACE) of 133.

Of the 5 total hurricanes, four became Major Hurricanes, and all reached Category 4+ intensity.

Today marks the official close of the 2025 Atlantic #hurricane season — a season defined by striking contrasts. From an unusually quiet peak to sudden bursts of extreme intensity, 2025 reinforced a critical lesson: a low storm count doesn't mean low risk.

#Melissa has set new benchmarks on several fronts.

Last year, I experienced Cat 1 Hurricane #Beryl making landfall in Houston. It was both terrifying and fascinating—an intense reminder of nature’s power and how small we can feel in its presence. I can’t imagine what the people of Jamaica and other countries in #Melissa’s path are going through.

#Melissa is undergoing explosive intensification — winds have surged 50 kt in 24 hours, including 35 kt in the last 12!
Jamaica faces a potentially catastrophic impact as the storm nears. And it’s not just the wind — the 4-day rainfall forecast is astronomical, with 30+ inches expected.

ICYMI: This week we released our Natural Catastrophe & Climate Report: Q3 2025

www.ajg.com/gallagherre/...

YTD Totals
Economic Loss: >$214bn (-37% from 10-Yr Avg)
Insured Loss: >$105bn (-8% from 10-Yr Avg)

US billion-dollar economic loss events: 20+ (7th year in a row)

(1/n)

A Nor’easter is battering the East Coast from Virginia to Connecticut, unleashing widespread flood warnings and powerful wind gusts reaching up to 60 mph—especially along the Jersey Shore.

Current projections:
🟪 3 gauges — Major Flood
🟥 17 gauges — Moderate Flood
🟧 40 gauges — Minor Flood

🚨 Open Call for new Steering Committee Members 🚨

Are you working on #risks from #extremeEvents under #environmentalChange?

Join us as Risk KAN Steering Committee member for the upcoming term: www.risk-kan.org/about-riskka...

www.risk-kan.org

@futureearth.bsky.social @wcrpclimate.bsky.social.

Forever in awe of this stunning view!

#NJ

#Erin has formed in the southeastern Atlantic and could potentially become the first hurricane of the season. While it’s still too early to determine if it poses a threat to the U.S. East Coast, conditions are becoming increasingly favorable for further intensification.

Moderate Risk of Excessive Rainfall Issued!
Affects areas along the I-95 corridor from Washington, D.C. to New York City. Rainfall rates may reach up to 3 inches per hour
Localized totals could exceed 5-8 inches.

Do NOT drive through floodwaters!

Can’t wait for your talk—already looking forward to it!

Stunning sunrise paints the sky over Newark International Airport.

Grateful for a few extra days to enjoy Florida after the Symposium on Tropical Cyclone Risk in a Changing Climate. A perfect way to unwind after an intense and inspiring week.

#STCRCC

Today is the "official" start to the Atlantic hurricane season. It is impossible to know what exactly will occur, but we can look to sea surface temperatures for clues.

2025 is definitely cooler than 2024 on June 1. Parts of the basin are warmer than recent analog years in 2008 / 2017.

(1/n)

Today we at Gallagher Re have released an initial assessment that estimates the May 14-20 stretch of US thunderstorms will drive $4-7 billion in insured losses. Uninsured damage is expected to drive the overall direct economic cost higher by at least another billion.

(1/2)

Moderate Risk (Level 4 of 5) issued for far North Texas, much of Central & Eastern Oklahoma, Southeast Kansas, and the Ozarks today. This continues the string of catastrophic convective storm systems that have battered parts of the U.S. in recent days.
#SevereWeather

1st Risk-KAN Symposium at IIASA The 1st Risk-KAN Symposium will be held on the 28th of April at the International Institute for Applied Systems Analysis (IIASA).

Excited to host the first #RiskKAN symposium at @iiasa.ac.at with presentations and a panel on #multi-hazard risks in a changing world on april 28th.

This kicks-off the new #Risk-KAN WG-structure co-chaired by @marleenderuiter.bsky.social, S.Singh and myself.

iiasa.ac.at/events/apr-2...

The entire section three centers around that message. Our main point is that no single player is solely responsible for covering these rising costs—it requires shared responsibility among key stakeholders. All of the strategies outlined in Figure 2 emphasize the involvement of these critical actors.

The growing void in the U.S. homeowners insurance market: who should bear the rising cost of climate change? - npj Climate Action npj Climate Action - The growing void in the U.S. homeowners insurance market: who should bear the rising cost of climate change?

Link to the article: www.nature.com/articles/s44...

This is a complex challenge with no simple fix. We outlined several actionable strategies—from advancing innovation in risk pricing, to improving data transparency, and strengthening community and infrastructure resilience. Above all, we emphasize the need for stronger public-private collaboration.

The re/insurance retreat isn’t just a homeowners’ issue—it reflects deeper vulnerabilities across our real estate markets and broader financial systems.