Erik R. Nielsen
@eniels13.bsky.social
Colorado State Atmospheric Science Ph.D. '19 | Texas A&M Meteorology '13 | Studies concurrent, collocated tornado and flash flood events | San Antonio Spurs Fan
Reposted by Erik R. Nielsen
Annotating a long 3+ day loop of #Hurricane #Melissa from Kingston, #Jamaica radar.
2️⃣ periods appear where an eyewall replacement cycle, #ERC, looked underway. In both cases, inner eyewall stayed intact & outer bands merged, resulting in a larger eye & strengthening after.
A remarkable evolution 🌀
2️⃣ periods appear where an eyewall replacement cycle, #ERC, looked underway. In both cases, inner eyewall stayed intact & outer bands merged, resulting in a larger eye & strengthening after.
A remarkable evolution 🌀
October 30, 2025 at 6:54 AM
Annotating a long 3+ day loop of #Hurricane #Melissa from Kingston, #Jamaica radar.
2️⃣ periods appear where an eyewall replacement cycle, #ERC, looked underway. In both cases, inner eyewall stayed intact & outer bands merged, resulting in a larger eye & strengthening after.
A remarkable evolution 🌀
2️⃣ periods appear where an eyewall replacement cycle, #ERC, looked underway. In both cases, inner eyewall stayed intact & outer bands merged, resulting in a larger eye & strengthening after.
A remarkable evolution 🌀
Reposted by Erik R. Nielsen
The Copernicus Sentinel-2 polar-orbiting satellite made an extremely fortuitous pass over Hurricane Melissa right before it made landfall in Jamaica to provide these stunning images of one of the most powerful Atlantic hurricanes in history
October 28, 2025 at 10:04 PM
The Copernicus Sentinel-2 polar-orbiting satellite made an extremely fortuitous pass over Hurricane Melissa right before it made landfall in Jamaica to provide these stunning images of one of the most powerful Atlantic hurricanes in history
Reposted by Erik R. Nielsen
I was worried for my crew mates when I saw them circling in the eye for over 20 mins. Looks like the very rough ride was confirmed. Plane had to leave early. They reported svr turb and a "sawtooth" eye. Looks like they moved 600-700ft up & down during this stretch in ~1 min.
October 28, 2025 at 4:23 PM
I was worried for my crew mates when I saw them circling in the eye for over 20 mins. Looks like the very rough ride was confirmed. Plane had to leave early. They reported svr turb and a "sawtooth" eye. Looks like they moved 600-700ft up & down during this stretch in ~1 min.
Reposted by Erik R. Nielsen
This has probably already been posted here, but Melissa has displayed a classic mesovortex pattern that can be modeled in the simplest 2D atmospheric models ("nondivergent barotropic models"). Here's a comparison of this morning's VIS sat and Kossin and Schubert (2001) experiments.
October 28, 2025 at 4:48 PM
This has probably already been posted here, but Melissa has displayed a classic mesovortex pattern that can be modeled in the simplest 2D atmospheric models ("nondivergent barotropic models"). Here's a comparison of this morning's VIS sat and Kossin and Schubert (2001) experiments.
Reposted by Erik R. Nielsen
Looking back at the rapid intensification of #Melissa, two things really stand out to me:
1) there were *5* consecutive six-hourly periods of RI
2) an RI period began when the storm was already at Category 4 intensity
The red entries here highlight when an RI period began (30+ kt in 24 hr).
1) there were *5* consecutive six-hourly periods of RI
2) an RI period began when the storm was already at Category 4 intensity
The red entries here highlight when an RI period began (30+ kt in 24 hr).
October 28, 2025 at 12:21 PM
Looking back at the rapid intensification of #Melissa, two things really stand out to me:
1) there were *5* consecutive six-hourly periods of RI
2) an RI period began when the storm was already at Category 4 intensity
The red entries here highlight when an RI period began (30+ kt in 24 hr).
1) there were *5* consecutive six-hourly periods of RI
2) an RI period began when the storm was already at Category 4 intensity
The red entries here highlight when an RI period began (30+ kt in 24 hr).
Reposted by Erik R. Nielsen
1-minute #GOES19/#GOESEast Visible and Infrared images with plots of GLM Flash Points showed prolific lightning activity within the inner eyewall of Category 5 Hurricane #Melissa as it approaches the SW coast of Jamaica. Low-altitude mesovortices persist within the eye.
October 28, 2025 at 2:32 PM
1-minute #GOES19/#GOESEast Visible and Infrared images with plots of GLM Flash Points showed prolific lightning activity within the inner eyewall of Category 5 Hurricane #Melissa as it approaches the SW coast of Jamaica. Low-altitude mesovortices persist within the eye.
Reposted by Erik R. Nielsen
A 10am EDT update from the National Hurricane Center now puts Melissa's sustained winds at 185 mph. Full text: www.nhc.noaa.gov/text/refresh...?
October 28, 2025 at 2:06 PM
A 10am EDT update from the National Hurricane Center now puts Melissa's sustained winds at 185 mph. Full text: www.nhc.noaa.gov/text/refresh...?
Reposted by Erik R. Nielsen
This is hands down the most extraordinary dropsonde in Atlantic recon history.
October 28, 2025 at 2:18 PM
This is hands down the most extraordinary dropsonde in Atlantic recon history.
Reposted by Erik R. Nielsen
The most recent recon data suggests that Melissa continues to intensify. Central pressure now down to 907 mb and a dropsonde released in the northeast eyewall measured a mean wind in the lower 150m of 185 knots (213 mph). This hurricane is truly in rarefied air as far as Atlantic hurricanes.
October 27, 2025 at 4:45 PM
The most recent recon data suggests that Melissa continues to intensify. Central pressure now down to 907 mb and a dropsonde released in the northeast eyewall measured a mean wind in the lower 150m of 185 knots (213 mph). This hurricane is truly in rarefied air as far as Atlantic hurricanes.
Reposted by Erik R. Nielsen
Here it is. The last 10 years of hail events across the U.S. using my prototype hail tracking algorithm!
Hoping to build out a more robust climatology of hailstorms like we have for tornadoes.
Hoping to build out a more robust climatology of hailstorms like we have for tornadoes.
October 6, 2025 at 4:33 PM
Here it is. The last 10 years of hail events across the U.S. using my prototype hail tracking algorithm!
Hoping to build out a more robust climatology of hailstorms like we have for tornadoes.
Hoping to build out a more robust climatology of hailstorms like we have for tornadoes.
Reposted by Erik R. Nielsen
Reposted by Erik R. Nielsen
“Those who can make you believe absurdities, can make you commit atrocities.” - Voltaire.
October 2, 2025 at 3:45 PM
“Those who can make you believe absurdities, can make you commit atrocities.” - Voltaire.
Reposted by Erik R. Nielsen
Here is a 4-day track summary of Hurricanes #Humberto and #Imelda, showcasing an example of the #Fujiwhara Effect. They approached and interacted with each other, coming within 465 miles, but did not complete an orbit around a common center or merge before moving back away from each other.
[1/4]
[1/4]
October 1, 2025 at 7:09 PM
Here is a 4-day track summary of Hurricanes #Humberto and #Imelda, showcasing an example of the #Fujiwhara Effect. They approached and interacted with each other, coming within 465 miles, but did not complete an orbit around a common center or merge before moving back away from each other.
[1/4]
[1/4]
Reposted by Erik R. Nielsen
The center of high pressure in the Southeast United States is revealed by dotted cumulus clouds in a circular pattern.
Areas of high pressure often dominate the broad atmospheric circulation in which clouds flow within. (2/3)
Areas of high pressure often dominate the broad atmospheric circulation in which clouds flow within. (2/3)
September 12, 2025 at 9:13 PM
The center of high pressure in the Southeast United States is revealed by dotted cumulus clouds in a circular pattern.
Areas of high pressure often dominate the broad atmospheric circulation in which clouds flow within. (2/3)
Areas of high pressure often dominate the broad atmospheric circulation in which clouds flow within. (2/3)
Reposted by Erik R. Nielsen
🚨 Recruiting Two PhD/MS Students 🚨
I am looking to bring on at least two GRAs (M.S. or Ph.D. Level) beginning Spring or Fall 2026 to join our CHAOS research group. Research projects will be related to artificial intelligence and machine learning applications for extreme temperatures and rainfall
I am looking to bring on at least two GRAs (M.S. or Ph.D. Level) beginning Spring or Fall 2026 to join our CHAOS research group. Research projects will be related to artificial intelligence and machine learning applications for extreme temperatures and rainfall
September 8, 2025 at 4:21 PM
🚨 Recruiting Two PhD/MS Students 🚨
I am looking to bring on at least two GRAs (M.S. or Ph.D. Level) beginning Spring or Fall 2026 to join our CHAOS research group. Research projects will be related to artificial intelligence and machine learning applications for extreme temperatures and rainfall
I am looking to bring on at least two GRAs (M.S. or Ph.D. Level) beginning Spring or Fall 2026 to join our CHAOS research group. Research projects will be related to artificial intelligence and machine learning applications for extreme temperatures and rainfall
Reposted by Erik R. Nielsen
Here’s a look at six new measures lawmakers just passed — and what these bills will do if Abbott signs them into law.
Sirens, summer camps and weather alerts: Here’s what is changing in Texas after the special session
When the governor called the Texas Legislature into special session after July’s historic floods, he topped his priority list with passing bills to better prepare the state for future natural…
www.texasstandard.org
September 5, 2025 at 2:45 PM
Here’s a look at six new measures lawmakers just passed — and what these bills will do if Abbott signs them into law.
Reposted by Erik R. Nielsen
NWS is hiring! Lead Meteorologist (Job Series - 1340) openings are now on USAJobs.gov. Use your science, technical, and communication skills to lead shifts, issue critical forecasts and warnings, and help protect lives and property. Apply today!
September 2, 2025 at 7:40 PM
NWS is hiring! Lead Meteorologist (Job Series - 1340) openings are now on USAJobs.gov. Use your science, technical, and communication skills to lead shifts, issue critical forecasts and warnings, and help protect lives and property. Apply today!
Reposted by Erik R. Nielsen
🎊We are thrilled to announce the 2026 Award and Honors Recipients!
Thank you to our members and friends for nominating these exceptional individuals and organizations making a difference in the weather, water, and climate fields.
Meet the recipients here: https://bit.ly/4lHUgaZ
Thank you to our members and friends for nominating these exceptional individuals and organizations making a difference in the weather, water, and climate fields.
Meet the recipients here: https://bit.ly/4lHUgaZ
August 27, 2025 at 1:15 PM
🎊We are thrilled to announce the 2026 Award and Honors Recipients!
Thank you to our members and friends for nominating these exceptional individuals and organizations making a difference in the weather, water, and climate fields.
Meet the recipients here: https://bit.ly/4lHUgaZ
Thank you to our members and friends for nominating these exceptional individuals and organizations making a difference in the weather, water, and climate fields.
Meet the recipients here: https://bit.ly/4lHUgaZ
Reposted by Erik R. Nielsen
🚨 The @nws.noaa.gov is hiring #Meteorologists! 🚨
A total of 40 entry-level #Meteorologist positions are now open across multiple Weather Forecast Offices nationwide, closing #September 8th.
Link: www.usajobs.gov/Search/Resul...
#Hiring #Meteorology #STEM #FederalJobs
A total of 40 entry-level #Meteorologist positions are now open across multiple Weather Forecast Offices nationwide, closing #September 8th.
Link: www.usajobs.gov/Search/Resul...
#Hiring #Meteorology #STEM #FederalJobs
August 25, 2025 at 1:53 PM
🚨 The @nws.noaa.gov is hiring #Meteorologists! 🚨
A total of 40 entry-level #Meteorologist positions are now open across multiple Weather Forecast Offices nationwide, closing #September 8th.
Link: www.usajobs.gov/Search/Resul...
#Hiring #Meteorology #STEM #FederalJobs
A total of 40 entry-level #Meteorologist positions are now open across multiple Weather Forecast Offices nationwide, closing #September 8th.
Link: www.usajobs.gov/Search/Resul...
#Hiring #Meteorology #STEM #FederalJobs
Reposted by Erik R. Nielsen
Here’s a first-of-its-kind vertical cross-section analysis of the eyewall of Category 5 Hurricane Erin, captured by AgileRadar’s ROARS radar system installed on NOAA’s Hurricane Hunters P-3 aircraft.
August 20, 2025 at 4:07 PM
Here’s a first-of-its-kind vertical cross-section analysis of the eyewall of Category 5 Hurricane Erin, captured by AgileRadar’s ROARS radar system installed on NOAA’s Hurricane Hunters P-3 aircraft.
Reposted by Erik R. Nielsen
Yeah, my database shows this as a record for most-delayed LSR...
[Delayed Report] On Aug 19, at 4:53 PM CDT, 4 SE Mead [Saunders Co, NE] Mesonet reports Tstm Wnd Gst of M128 MPH. Very delayed report (2021). Received from UNL School of Natural Resources. Appears to have occurred in the rear flank downdraft... #newx Link
August 19, 2025 at 5:22 PM
Yeah, my database shows this as a record for most-delayed LSR...
Reposted by Erik R. Nielsen
It’s been 42 years — August 18, 1983 — since Hurricane Alicia made landfall in Southeast TX. Galveston WSR-57 radar loop from HRD and NWS HGX.
August 18, 2025 at 5:02 PM
It’s been 42 years — August 18, 1983 — since Hurricane Alicia made landfall in Southeast TX. Galveston WSR-57 radar loop from HRD and NWS HGX.
Reposted by Erik R. Nielsen
The @ametsoc.org will be hosting a webinar about @nws.noaa.gov hiring, and the changes in the overall process on #August 20th at 12 PM EDT. Please consider registering if you are interested in upcoming or ongoing announcements. #Meteorology #Hydrology #ElectronicsTechnician #PhysicalScientist
August 12, 2025 at 7:52 PM
The @ametsoc.org will be hosting a webinar about @nws.noaa.gov hiring, and the changes in the overall process on #August 20th at 12 PM EDT. Please consider registering if you are interested in upcoming or ongoing announcements. #Meteorology #Hydrology #ElectronicsTechnician #PhysicalScientist
So...uhh that is an impressive heat index:
METAR OIKQ 280700Z 09010KT 7000 NSC 38/33 Q0997 NOSIG
This is the part of the world where values like this can occur. Lots of interesting things going on in the trace leading up to it. Clear sensitivities to wind direction and mixing.
METAR OIKQ 280700Z 09010KT 7000 NSC 38/33 Q0997 NOSIG
This is the part of the world where values like this can occur. Lots of interesting things going on in the trace leading up to it. Clear sensitivities to wind direction and mixing.
July 29, 2025 at 5:40 PM
So...uhh that is an impressive heat index:
METAR OIKQ 280700Z 09010KT 7000 NSC 38/33 Q0997 NOSIG
This is the part of the world where values like this can occur. Lots of interesting things going on in the trace leading up to it. Clear sensitivities to wind direction and mixing.
METAR OIKQ 280700Z 09010KT 7000 NSC 38/33 Q0997 NOSIG
This is the part of the world where values like this can occur. Lots of interesting things going on in the trace leading up to it. Clear sensitivities to wind direction and mixing.