Clark Evans
@clarkevanswx.bsky.social
I study high-impact weather, help develop high-resolution models to improve weather forecasts, and mentor scientists. Constantly striving to help those around me flourish. My views expressed here are mine alone.
Pinned
Clark Evans
@clarkevanswx.bsky.social
· Sep 29
NOAA Testbeds help GSL advance forecast and weather information systems| NOAA OAR GSL
Global Systems Laboratory
gsl.noaa.gov
None of NOAA’s line offices work in isolation. At GSL, we’re proud to engage with our NWS colleagues on testing and evaluating the modeling system and service innovations — which we then use to make them better before reaching operations! Here’s how we’re doing so now:
gsl.noaa.gov/news/noaa-te...
gsl.noaa.gov/news/noaa-te...
Reposted by Clark Evans
Very disheartened by the UNL chancellor's decision to recommend the Earth & Atmospheric Sciences Department for elimination, despite the opposition from the Academic Planning Committee's vote.
Both the opposing and in favor summary noted the value EAS provides to the discipline, and both sides
Both the opposing and in favor summary noted the value EAS provides to the discipline, and both sides
November 11, 2025 at 3:23 AM
Very disheartened by the UNL chancellor's decision to recommend the Earth & Atmospheric Sciences Department for elimination, despite the opposition from the Academic Planning Committee's vote.
Both the opposing and in favor summary noted the value EAS provides to the discipline, and both sides
Both the opposing and in favor summary noted the value EAS provides to the discipline, and both sides
Disappointing news out of Nebraska, where the University's Chancellor's Final Budget Reduction Plan continues to call for eliminating the Dept of Earth & Atmospheric Sciences - notably, against the recommendation of the university's Academic Planning Committee.
budgetprocess.unl.edu/final-budget...
budgetprocess.unl.edu/final-budget...
Final Budget Reduction Plan | Budget Process | Nebraska
budgetprocess.unl.edu
November 11, 2025 at 12:48 AM
Disappointing news out of Nebraska, where the University's Chancellor's Final Budget Reduction Plan continues to call for eliminating the Dept of Earth & Atmospheric Sciences - notably, against the recommendation of the university's Academic Planning Committee.
budgetprocess.unl.edu/final-budget...
budgetprocess.unl.edu/final-budget...
Reposted by Clark Evans
Applications are open for the @ncar-cisl.bsky.social SIParCS summer internship program! It's a great opportunity for computationally-inclined students to get experience with real-world research problems spanning computational and Earth System Science. Link: ucar.wd5.myworkdayjobs.com/en-US/UCAR_C...
2026 SIParCS Undergraduate Student Internships
Job Description Summary: The Summer Internships in Parallel Computational Science (SIParCS) program at the National Center for Atmospheric Research (NCAR) offers graduate students and undergraduates w...
ucar.wd5.myworkdayjobs.com
November 3, 2025 at 10:59 PM
Applications are open for the @ncar-cisl.bsky.social SIParCS summer internship program! It's a great opportunity for computationally-inclined students to get experience with real-world research problems spanning computational and Earth System Science. Link: ucar.wd5.myworkdayjobs.com/en-US/UCAR_C...
Reposted by Clark Evans
Undergraduate opportunity! 📣 The NSF SOARS program is open for applications! SOARS is an undergrad-grad bridge program focusing on promoting and supporting research, mentoring, and community.
Learn more about eligibility and the app process:
ucar.wd5.myworkdayjobs.com/en-US/UCAR_C...
Learn more about eligibility and the app process:
ucar.wd5.myworkdayjobs.com/en-US/UCAR_C...
2026 NSF SOARS® First-Year Protege
Job Description Summary: UCAR is excited to announce the application opening of the U.S. National Science Foundation (NSF) Significant Opportunities in Atmospheric Research and Science (SOARS) program...
ucar.wd5.myworkdayjobs.com
November 3, 2025 at 8:57 PM
Undergraduate opportunity! 📣 The NSF SOARS program is open for applications! SOARS is an undergrad-grad bridge program focusing on promoting and supporting research, mentoring, and community.
Learn more about eligibility and the app process:
ucar.wd5.myworkdayjobs.com/en-US/UCAR_C...
Learn more about eligibility and the app process:
ucar.wd5.myworkdayjobs.com/en-US/UCAR_C...
Reposted by Clark Evans
Here is a zoomed in radar version of 28 Oct showing #Melissa 's inner core evolution before #Jamaica landfall.
Radar evidence some type of fast eyewall replacement cycle, #ERC, occurred. Eye went from 10 n mi to 15 n mi on VDM fixes & more intensification occured after ERC.
Horrible for Jamaica 😞
Radar evidence some type of fast eyewall replacement cycle, #ERC, occurred. Eye went from 10 n mi to 15 n mi on VDM fixes & more intensification occured after ERC.
Horrible for Jamaica 😞
November 3, 2025 at 6:10 PM
In this article and the broader discourse about a possible “cat 6,” I’m fascinated by the dichotomy between the climate-centric scientists who are largely in favor of a cat-6 and the tropical cyclone-centric scientists who largely aren’t. (1/3)
As climate change super-sizes our storms, should our categories reflect that?
Thoughtful comments and discussion (all too rare today) from @weatherprof.bsky.social, @michaelemann.bsky.social, myself and others.
Check it out and LMK - what do YOU think?
Thoughtful comments and discussion (all too rare today) from @weatherprof.bsky.social, @michaelemann.bsky.social, myself and others.
Check it out and LMK - what do YOU think?
Category 6 is the new hurricane normal, say scientists
Human-caused climate change is making major hurricanes like Melissa much stronger, faster and ultimately more life-threatening
www.independent.co.uk
November 3, 2025 at 1:28 AM
In this article and the broader discourse about a possible “cat 6,” I’m fascinated by the dichotomy between the climate-centric scientists who are largely in favor of a cat-6 and the tropical cyclone-centric scientists who largely aren’t. (1/3)
“At 82 degrees in Denver, we have broken today's record high (78 set in 2008 and 1931) and broken the all time monthly record high (81 set 11/17/2017).” #cowx
#BOU issues Area Forecast Discussion (AFD) at Nov 2, 2:02 PM MST Link
November 2, 2025 at 9:08 PM
“At 82 degrees in Denver, we have broken today's record high (78 set in 2008 and 1931) and broken the all time monthly record high (81 set 11/17/2017).” #cowx
Reposted by Clark Evans
Life safety wise, in a warming world, we need more people to take more action at lower SSHWS categories anyway for water. This won’t help more people buy flood insurance, or evacuate. It could theoretically do more harm than good messaging wise. This is my *least* favorite hurricane convo. 😂
October 29, 2025 at 3:21 PM
Life safety wise, in a warming world, we need more people to take more action at lower SSHWS categories anyway for water. This won’t help more people buy flood insurance, or evacuate. It could theoretically do more harm than good messaging wise. This is my *least* favorite hurricane convo. 😂
Reposted by Clark Evans
The bomb plot that brought down the United Mainliner over Weld Counry killed 44, showed planes could be targets and changed laws. Witnesses recall the scene as officials prepare to dedicate a memorial to victims on Nov. 1.
70 years ago, a Colorado man plotted to kill his mother. How he carried it out shocked the nation.
Surviving witnesses recall the bomb plot that brought down United Air Lines Flight 629 over Weld County as a memorial dedication is planned
coloradosun.com
October 28, 2025 at 5:38 PM
The bomb plot that brought down the United Mainliner over Weld Counry killed 44, showed planes could be targets and changed laws. Witnesses recall the scene as officials prepare to dedicate a memorial to victims on Nov. 1.
Reposted by Clark Evans
#Melissa's landfall intensity of 185 mph/892 mb ties it with the Florida Key's Labor Day Hurricane of 1935 as the record minimum pressure of any TC making landfall *anywhere* the NATL basin. I feel for the residents of #Jamaica 😞
Zoomed in G19 visible meso loop courtesy of @cyclonicwx.bsky.social
Zoomed in G19 visible meso loop courtesy of @cyclonicwx.bsky.social
October 28, 2025 at 5:14 PM
#Melissa's landfall intensity of 185 mph/892 mb ties it with the Florida Key's Labor Day Hurricane of 1935 as the record minimum pressure of any TC making landfall *anywhere* the NATL basin. I feel for the residents of #Jamaica 😞
Zoomed in G19 visible meso loop courtesy of @cyclonicwx.bsky.social
Zoomed in G19 visible meso loop courtesy of @cyclonicwx.bsky.social
Reposted by Clark Evans
Speculation on my part but my hypotheses:
1) Residual mid-level shear of 15-25kt kept rainbands from forming on Melissa’s W side. Despite symmetric core, 34-kt radii was very asymmetric due to shear/convective asymmetry.
2) 30-31C SSTs moistening BL dry air n/ core preventing inner eyewall decay.
1) Residual mid-level shear of 15-25kt kept rainbands from forming on Melissa’s W side. Despite symmetric core, 34-kt radii was very asymmetric due to shear/convective asymmetry.
2) 30-31C SSTs moistening BL dry air n/ core preventing inner eyewall decay.
October 28, 2025 at 4:02 PM
Speculation on my part but my hypotheses:
1) Residual mid-level shear of 15-25kt kept rainbands from forming on Melissa’s W side. Despite symmetric core, 34-kt radii was very asymmetric due to shear/convective asymmetry.
2) 30-31C SSTs moistening BL dry air n/ core preventing inner eyewall decay.
1) Residual mid-level shear of 15-25kt kept rainbands from forming on Melissa’s W side. Despite symmetric core, 34-kt radii was very asymmetric due to shear/convective asymmetry.
2) 30-31C SSTs moistening BL dry air n/ core preventing inner eyewall decay.
Reposted by Clark Evans
There were a few times I thought an ERC was beginning, only for it to vanish quickly.
I like @pppapin.bsky.social hypotheses. I'd also look at the radial vorticity profile to see it there was something anomalous about it.
Ultimately, what was missing for an ERC? Someone's PhD dissertation waiting.
I like @pppapin.bsky.social hypotheses. I'd also look at the radial vorticity profile to see it there was something anomalous about it.
Ultimately, what was missing for an ERC? Someone's PhD dissertation waiting.
October 28, 2025 at 4:13 PM
There were a few times I thought an ERC was beginning, only for it to vanish quickly.
I like @pppapin.bsky.social hypotheses. I'd also look at the radial vorticity profile to see it there was something anomalous about it.
Ultimately, what was missing for an ERC? Someone's PhD dissertation waiting.
I like @pppapin.bsky.social hypotheses. I'd also look at the radial vorticity profile to see it there was something anomalous about it.
Ultimately, what was missing for an ERC? Someone's PhD dissertation waiting.
Reposted by Clark Evans
📢The Anemoi training-ready ERA5 dataset is now openly available!
A ready-to-use, ML-optimised subset of ERA5 in cloud-friendly Zarr format, hosted by ECMWF and free under CC-BY-4.0.
Read the AIFS blog: ➡️ www.ecmwf.int/en/about/med...
A ready-to-use, ML-optimised subset of ERA5 in cloud-friendly Zarr format, hosted by ECMWF and free under CC-BY-4.0.
Read the AIFS blog: ➡️ www.ecmwf.int/en/about/med...
October 28, 2025 at 12:33 PM
📢The Anemoi training-ready ERA5 dataset is now openly available!
A ready-to-use, ML-optimised subset of ERA5 in cloud-friendly Zarr format, hosted by ECMWF and free under CC-BY-4.0.
Read the AIFS blog: ➡️ www.ecmwf.int/en/about/med...
A ready-to-use, ML-optimised subset of ERA5 in cloud-friendly Zarr format, hosted by ECMWF and free under CC-BY-4.0.
Read the AIFS blog: ➡️ www.ecmwf.int/en/about/med...
Per NOAA/AOML/HRD’s Sim Aberson, the 219 kt reading will be the fastest wind ever measured by a dropsonde if it passes final quality-control checks.
This is hands down the most extraordinary dropsonde in Atlantic recon history.
October 28, 2025 at 3:41 PM
Per NOAA/AOML/HRD’s Sim Aberson, the 219 kt reading will be the fastest wind ever measured by a dropsonde if it passes final quality-control checks.
Signed, a Braves fan who bought his jersey after the 2021 World Series and continues to rue the day the Braves let him go.
Of *course* it’s Freddie Freeman who walks it off.
October 28, 2025 at 6:52 AM
Signed, a Braves fan who bought his jersey after the 2021 World Series and continues to rue the day the Braves let him go.
Of *course* it’s Freddie Freeman who walks it off.
October 28, 2025 at 6:51 AM
Of *course* it’s Freddie Freeman who walks it off.
That’s…not at all how this works. As the NHC’s wind field image shows, Jamaica is only experiencing tropical storm-force winds right now, with weaker winds elsewhere. The most widespread and longest-lasting impact has and will be extreme rain - for which the prep is rather different than wind.
October 27, 2025 at 7:43 PM
That’s…not at all how this works. As the NHC’s wind field image shows, Jamaica is only experiencing tropical storm-force winds right now, with weaker winds elsewhere. The most widespread and longest-lasting impact has and will be extreme rain - for which the prep is rather different than wind.
Reposted by Clark Evans
Calling all ensemble forecast system enthusiasts! The State of Texas is funding development of a new ensemble prediction system (100 members, 2km grid spacing) with an embedded WoFS interface, to be developed at Texas Tech! Passing along 3 open research scientist positions towards that development:
October 27, 2025 at 5:13 PM
Calling all ensemble forecast system enthusiasts! The State of Texas is funding development of a new ensemble prediction system (100 members, 2km grid spacing) with an embedded WoFS interface, to be developed at Texas Tech! Passing along 3 open research scientist positions towards that development:
A question maybe best suited for @franklinjamesl.bsky.social:
Does the intensification of a TC like Melissa necessitate changing the standard flight-level wind reduction factor? While flight level stays 700 hPa, the 700 hPa height keeps dropping - now ~2550-2600 m in the eyewall. (1/2)
Does the intensification of a TC like Melissa necessitate changing the standard flight-level wind reduction factor? While flight level stays 700 hPa, the 700 hPa height keeps dropping - now ~2550-2600 m in the eyewall. (1/2)
October 27, 2025 at 5:14 PM
A question maybe best suited for @franklinjamesl.bsky.social:
Does the intensification of a TC like Melissa necessitate changing the standard flight-level wind reduction factor? While flight level stays 700 hPa, the 700 hPa height keeps dropping - now ~2550-2600 m in the eyewall. (1/2)
Does the intensification of a TC like Melissa necessitate changing the standard flight-level wind reduction factor? While flight level stays 700 hPa, the 700 hPa height keeps dropping - now ~2550-2600 m in the eyewall. (1/2)
#Melissa continues to intensify, with the current recon eye penetration documenting 161 kt winds at flight level in the northeastern eyewall and an extrapolated minimum sea-level pressure of 905.6 hPa.
October 27, 2025 at 3:59 PM
#Melissa continues to intensify, with the current recon eye penetration documenting 161 kt winds at flight level in the northeastern eyewall and an extrapolated minimum sea-level pressure of 905.6 hPa.
And a sonde from the southeastern eyewall. It measured a surface wind of 125 kt, but 153 kt only 10 hPa (about 100 meters) above the surface.
The northwestern eyewall is where we’d expect the fastest winds for a westward-moving storm, so altogether, #Melissa is close to category-5 intensity.
The northwestern eyewall is where we’d expect the fastest winds for a westward-moving storm, so altogether, #Melissa is close to category-5 intensity.
October 27, 2025 at 6:19 AM
And a sonde from the southeastern eyewall. It measured a surface wind of 125 kt, but 153 kt only 10 hPa (about 100 meters) above the surface.
The northwestern eyewall is where we’d expect the fastest winds for a westward-moving storm, so altogether, #Melissa is close to category-5 intensity.
The northwestern eyewall is where we’d expect the fastest winds for a westward-moving storm, so altogether, #Melissa is close to category-5 intensity.
Here’s the first eye sonde from the overnight #Melissa recon flight. 925 hPa at the surface with a 16 kt wind is about 923 hPa at the true center - in line with the flight-level extrapolation.
October 27, 2025 at 6:11 AM
Here’s the first eye sonde from the overnight #Melissa recon flight. 925 hPa at the surface with a 16 kt wind is about 923 hPa at the true center - in line with the flight-level extrapolation.
144 kt flight-level winds on the northwest side of the eyewall. Should get 1-2 dropsonde profiles from the eye and eyewall in the next 10-20 minutes.
New recon flight into #Melissa just finished its first eyewall traverse, SE-NW. Minimum extrapolated SLP of 923.2 hPa, max flight-level winds of 140 kt, and 700-hPa height of 2504 m.
October 27, 2025 at 6:08 AM
144 kt flight-level winds on the northwest side of the eyewall. Should get 1-2 dropsonde profiles from the eye and eyewall in the next 10-20 minutes.
New recon flight into #Melissa just finished its first eyewall traverse, SE-NW. Minimum extrapolated SLP of 923.2 hPa, max flight-level winds of 140 kt, and 700-hPa height of 2504 m.
October 27, 2025 at 6:01 AM
New recon flight into #Melissa just finished its first eyewall traverse, SE-NW. Minimum extrapolated SLP of 923.2 hPa, max flight-level winds of 140 kt, and 700-hPa height of 2504 m.
Reposted by Clark Evans
my mortal college football enemy is the Daisy Sour Cream commercial
October 25, 2025 at 4:24 PM
my mortal college football enemy is the Daisy Sour Cream commercial