Michael Fischer
@mikefischerwx.bsky.social
Assistant Professor at the University of Miami. Usually discussing hurricanes.
To summarize, quickly aligning TCs have stronger and more compact low-level circulations, stronger lower tropospheric ascent near the low-level center, and tend to have a tilt configuration oriented more left-of-shear than persistently tilted TCs.
July 21, 2026 at 6:45 PM
To summarize, quickly aligning TCs have stronger and more compact low-level circulations, stronger lower tropospheric ascent near the low-level center, and tend to have a tilt configuration oriented more left-of-shear than persistently tilted TCs.
Tropical Storm #Bertha is a sheared and tilted tropical cyclone. But many TCs start out this way. What factors determine whether a storm can become aligned and intensify? Well, that is exactly what we explored in our recent publication: agupubs.onlinelibrary.wiley.com/doi/full/10....
July 21, 2026 at 6:44 PM
Tropical Storm #Bertha is a sheared and tilted tropical cyclone. But many TCs start out this way. What factors determine whether a storm can become aligned and intensify? Well, that is exactly what we explored in our recent publication: agupubs.onlinelibrary.wiley.com/doi/full/10....
It's the first day of hurricane season in the Atlantic. TC-ATLAS now features a real-time monitoring page with geostationary and microwave satellite data, real-time surface observations, and objective model forecasts from Google DeepMind. michaelfischerwx.github.io/TC-ATLAS/rea...
June 2, 2026 at 12:22 AM
It's the first day of hurricane season in the Atlantic. TC-ATLAS now features a real-time monitoring page with geostationary and microwave satellite data, real-time surface observations, and objective model forecasts from Google DeepMind. michaelfischerwx.github.io/TC-ATLAS/rea...
Hello friends, just a note that I have been steadily adding features over the last month+ to TC-ATLAS. This includes a real-time monitoring page for synoptic, subseasonal, and seasonal aspects. Examples attached. Check out more here: michaelfischerwx.github.io/TC-ATLAS/rea...
May 18, 2026 at 7:35 PM
Hello friends, just a note that I have been steadily adding features over the last month+ to TC-ATLAS. This includes a real-time monitoring page for synoptic, subseasonal, and seasonal aspects. Examples attached. Check out more here: michaelfischerwx.github.io/TC-ATLAS/rea...
Hello from 34k ft in the air as I’m headed to @AMSTropical. I just wanted to share that TC-ATLAS now features environmental diagnostics from ERA5 courtesy of TC-PRIMED and interactive NEXRAD radar data in the global archive page: michaelfischerwx.github.io/TC-ATLAS/ind...
March 31, 2026 at 2:09 AM
Hello from 34k ft in the air as I’m headed to @AMSTropical. I just wanted to share that TC-ATLAS now features environmental diagnostics from ERA5 courtesy of TC-PRIMED and interactive NEXRAD radar data in the global archive page: michaelfischerwx.github.io/TC-ATLAS/ind...
Quick screenshot from my phone. Feel free to explore more here: michaelfischerwx.github.io/TC-ATLAS/glo...
March 28, 2026 at 5:36 PM
Quick screenshot from my phone. Feel free to explore more here: michaelfischerwx.github.io/TC-ATLAS/glo...
One more new feature: The global archive page of TC-ATLAS now has a "models" toggle so you can review the evolution of past forecasts going back to 1991. Some notable examples of challenging forecasts below. michaelfischerwx.github.io/TC-ATLAS/ind...
March 28, 2026 at 5:15 PM
One more new feature: The global archive page of TC-ATLAS now has a "models" toggle so you can review the evolution of past forecasts going back to 1991. Some notable examples of challenging forecasts below. michaelfischerwx.github.io/TC-ATLAS/ind...
To highlight some of the capabilities, users can draw custom vertical cross-sections, compute shear-relative quadrant means, explore 3D isosurfaces, overlay IR and microwave obs on tail Doppler radar analyses, and even compute custom composites.
March 27, 2026 at 2:26 PM
To highlight some of the capabilities, users can draw custom vertical cross-sections, compute shear-relative quadrant means, explore 3D isosurfaces, overlay IR and microwave obs on tail Doppler radar analyses, and even compute custom composites.
Interested in hurricanes? I want to introduce TC-ATLAS: the Tropical Cyclone Analysis Tool for Live and Archived Structure. Explore live or past storms without writing a line of code or downloading a data file, building on the capabilities of TC-RADAR: michaelfischerwx.github.io/TC-ATLAS/ind...
March 27, 2026 at 2:25 PM
Interested in hurricanes? I want to introduce TC-ATLAS: the Tropical Cyclone Analysis Tool for Live and Archived Structure. Explore live or past storms without writing a line of code or downloading a data file, building on the capabilities of TC-RADAR: michaelfischerwx.github.io/TC-ATLAS/ind...
Unfortunately the sky was indeed the limit. Catastrophic #Melissa is on track to be the strongest hurricane to make landfall in the Atlantic in 90 years. Just absolutely gutted for the souls in Jamaica.
October 28, 2025 at 2:35 PM
Unfortunately the sky was indeed the limit. Catastrophic #Melissa is on track to be the strongest hurricane to make landfall in the Atlantic in 90 years. Just absolutely gutted for the souls in Jamaica.
#Melissa is intensifying very rapidly this evening. TDR structure is nearly perfect for a TC of this intensity. Incredibly symmetric, strong eyewall, and a deep, aligned circulation. The sky is the limit. Very scary situation.
October 26, 2025 at 12:03 AM
#Melissa is intensifying very rapidly this evening. TDR structure is nearly perfect for a TC of this intensity. Incredibly symmetric, strong eyewall, and a deep, aligned circulation. The sky is the limit. Very scary situation.
Ground-based radar imagery from Jamaica shows the core has continued to become better defined over the last six hours. A potentially catastrophic situation unfolding for Jamaica. #Melissa
October 25, 2025 at 6:01 PM
Ground-based radar imagery from Jamaica shows the core has continued to become better defined over the last six hours. A potentially catastrophic situation unfolding for Jamaica. #Melissa
#Melissa is about to undergo rapid intensification (RI). And I anticipate it will be quite explosive. A classic cyan ring on 37 GHz imagery from this GMI overpass at 1447 UTC.
October 25, 2025 at 4:15 PM
#Melissa is about to undergo rapid intensification (RI). And I anticipate it will be quite explosive. A classic cyan ring on 37 GHz imagery from this GMI overpass at 1447 UTC.
Two tropical cyclones churning in the western Atlantic. Here in FL, it’s business as usual. The power of modern meteorology.
September 29, 2025 at 12:27 PM
Two tropical cyclones churning in the western Atlantic. Here in FL, it’s business as usual. The power of modern meteorology.
This is one of the best satellite signatures I have ever seen in the SW Atlantic (non-Gulf/Caribbean). #Humberto is up there with storms like Andrew, Dorian, and Irma in my eyes.
September 27, 2025 at 5:33 PM
This is one of the best satellite signatures I have ever seen in the SW Atlantic (non-Gulf/Caribbean). #Humberto is up there with storms like Andrew, Dorian, and Irma in my eyes.
Update: Hurricane #Humberto has intensified 55 kt in the last 12 h… extreme RI ongoing. Anomalous upshear convection is again a tell for subsequent RI. Thankfully the storm is well away from land for now.
September 27, 2025 at 1:41 AM
Update: Hurricane #Humberto has intensified 55 kt in the last 12 h… extreme RI ongoing. Anomalous upshear convection is again a tell for subsequent RI. Thankfully the storm is well away from land for now.
Anomalous upshear convection is often associated with rapid intensification in hurricanes. Here is a schematic from my dissertation and a recent snapshot of Hurricane Humberto, which is experiencing westerly shear. Although Humberto is fairly compact, its structure suggests RI is ongoing.
September 26, 2025 at 1:07 PM
Anomalous upshear convection is often associated with rapid intensification in hurricanes. Here is a schematic from my dissertation and a recent snapshot of Hurricane Humberto, which is experiencing westerly shear. Although Humberto is fairly compact, its structure suggests RI is ongoing.
With anomalously weak trade winds, the eastern Main Development Region of the Atlantic has rapidly warmed over the last two weeks. Models suggest this flow pattern should largely continue, favoring additional warming.
July 11, 2025 at 2:42 PM
With anomalously weak trade winds, the eastern Main Development Region of the Atlantic has rapidly warmed over the last two weeks. Models suggest this flow pattern should largely continue, favoring additional warming.
Cyclone Errol is an extremely powerful storm. IR brightness temps in the eye are quite warm for a core that small. Reminds me of Milton in the Atlantic last year. And for my northern hemisphere friends, I have rotated the IR pattern to be consistent with a positive Coriolis value in the 2nd image.
April 16, 2025 at 12:02 PM
Cyclone Errol is an extremely powerful storm. IR brightness temps in the eye are quite warm for a core that small. Reminds me of Milton in the Atlantic last year. And for my northern hemisphere friends, I have rotated the IR pattern to be consistent with a positive Coriolis value in the 2nd image.
Uh oh. Zelia is explosively intensifying at this point. The enclosed pink ring in 36 GHz imagery is typically a signal only seen in extremely intense TCs or those about to be extremely intense.
February 12, 2025 at 9:16 PM
Uh oh. Zelia is explosively intensifying at this point. The enclosed pink ring in 36 GHz imagery is typically a signal only seen in extremely intense TCs or those about to be extremely intense.
Off the northwest coast of Australia, Cyclone Zelia appears to be intensifying quite quickly. Some of the hurricane guidance brings the system up to the equivalent of category-5 intensity before landfall. Hopefully that’s overly aggressive.
February 12, 2025 at 5:08 PM
Off the northwest coast of Australia, Cyclone Zelia appears to be intensifying quite quickly. Some of the hurricane guidance brings the system up to the equivalent of category-5 intensity before landfall. Hopefully that’s overly aggressive.
To summarize: RI tends to occur in vortices that are anomalously tall and narrow and in TCs with anomalously deep convection in the TC inner core. We hypothesize this helps evacuate mass out of the boundary layer, leading to the inward advection of angular momentum surfaces.
December 13, 2024 at 10:33 PM
To summarize: RI tends to occur in vortices that are anomalously tall and narrow and in TCs with anomalously deep convection in the TC inner core. We hypothesize this helps evacuate mass out of the boundary layer, leading to the inward advection of angular momentum surfaces.