Julia is the *first* in a line of NHP graduate students joining the ranks of Canada's next generation of severe weather scientists. We wish Julia all the very the best and look forward to her continued and future contributions to hail science! @cssl.ca

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Julia standing proudly in front of opening slide of her master's thesis defense presentation with supervisors Dr. Greg Kopp and Dr. Julian Brimelow.

**Important Announcement!**

Today, we congratulate NHP graduate student Julia Finlayson on the successful defense of her master's thesis, entitled "Development of a Low-Cost, Novel Piezoresistive Polymer Hail Sensor" under the supervision of Drs. Gregory Kopp and Julian Brimelow.

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I'm excited to share that my latest paper focused on the internship program at @cssl.ca is now available as an early online release in the Bulletin of the American Meteorological Society!

doi.org/10.1175/BAMS...

Canadian Mesonet Portal Update (v2026.04.05): Pro Version & More! This release introduces the Pro Version of the Canadian Mesonet Portal, a major expansion of the platform focused on deeper data access, and advanced analysis tools. Alongside the Pro Version, we’ve d...

Big update 🚀

We’ve launched the Pro Version of the Canadian Mesonet Portal, along with major improvements across all versions of the platform! Pro Version features will continue rolling out gradually throughout the month, so keep an eye out!

Details:
www.uwo.ca/nmp/news/202...

An unusually active and destructive start to the tornado season in the northern U.S. has many Canadians wondering what's in store north of the border.

Watch more video: https://ow.ly/XrYc50YzWMC

*Survey Announcement*

Due to the rare nature of last week's hail event, researchers from the NHP & NTP will be conducting a damage survey tomorrow (March 21) of the region S and SW of Hopeville.

Please let us know if you have any damage reports or other info! #onstorm @westernuntp.bsky.social

CSSL 2025 Annual Report cover spread

The first CSSL Annual Report - covering the CSSL's inaugural full year in 2025 - is now available! Please visit uwo.ca/cssl/news.html to download a copy.

Western University Western University, in vibrant London, Ontario, delivers an academic and student experience second to none.

The Northern Mesonet Project at the Canadian Severe Storms Laboratory (@cssl.ca) is looking for a Research Software Engineer to join our team!

Please feel free to share with anyone who may be interested! You can find the details of the position (ID# 41923) here: www.uwo.ca/hr/working/s...

The CSSL is supporting another storm-themed artistic experience, this time an exhibit at Western's McIntosh Gallery called 'Atmospheric Shifts'. Details and artist bios:

mcintoshgallery.ca/exhibitions/...

Below are some photos from my recent visit. I'm happy to have 2 of my own tornado prints up!

Last call! Internship applications close on Monday at 11:59PM ET

Heads up - the first info session for the CSSL Summer Internship Program is tonight!

Find the details here: uwo.ca/cssl/interns...

Dive into real-world research and fieldwork with the CSSL Summer Internship Program!

Learn more and apply here: uwo.ca/cssl/interns...

Don't miss your chance to gain hands-on experience with leading tornado and hail experts in the field.

Applications close on January 26th.

"Synthetic Aperture Radar as a Tool for Tornado Classification in Forested Areas" demonstrates how SAR can reveal tornado damage signatures in strong tornadoes, offering a way to provide EF-scale ratings in heavily forested regions where optical imagery struggles (doi.org/10.1080/0703...).

These papers highlight complementary remote sensing approaches that can help improve spatial coverage and consistency of tornado intensity assessments. Grateful for @cssl.ca team who made these studies possible!

"Evaluating the Utility of NDVI as a Damage Indicator for Crops in the Enhanced Fujita Scale" tests how NDVI changes can be used to identify crop damage from tornadoes, describes limitations, and shows how NDVI can supplement ground surveys in agricultural areas (doi.org/10.1175/JAMC...).

I'm happy to share two @cssl.ca open-access remote sensing papers that are both related to alternative methods of classifying tornado damage! 🧵:

Drone photo courtesy Brian Emfinger and used with permission.

The CSSL/NTP assisted the US National Weather Service (NWS) with their upgrading of the official rating of the June 2025 Enderlin, ND tornado from EF3 to EF5.

Announced by the NWS today, it’s the first EF5-rated tornado in the US since 2013.

Details here: uwo.ca/ntp/blog/202...

Image B. Emfinger

Excited to announce that my method for estimating wind speeds based on lofted debris in tornadoes was used as contextual evidence for upgrading the Enderlin, ND tornado to an EF5!

doi.org/10.1175/MWR-...

#NDwx #Enderlin #EF5 #Tornado

Two new open access journal papers today from CSSL researchers!

Stochastic Modeling of Radar-derived Maximum Estimated Size of Hail for Scenario-based Hail Loss Estimation
doi.org/10.1016/j.ij...

Multi-Level In-Situ Measurements During a Direct Hit by a Significant Tornado
doi.org/10.1080/0705...

**Damage Survey Announcement: Following an extreme rainfall event and resulting flash flooding across SE Manitoba on Sept 11 & 12, a CSSL damage survey team will be conducting an assessment of the event's impacts. Please let us know if you have any rainfall and/or damage reports! #mbstorm @cssl.ca

The NTP has confirmed that a downburst (paired with large hail) caused high-end EF1 damage in the Brooks, AB area on August 20.

Details at the NTP blog here: uwo.ca/ntp/blog/202...

Note that ongoing analysis may result in additional events and/or a rating upgrade.

#ABstorm #SKstorm

The NTP has confirmed two EF1 downbursts (one being a microburst), an EF0 tornado and a gustnado from the SK storms of Aug 20 near Saskatoon.

The assessments are based on witness reports, an NTP damage survey, and radar/satellite imagery analysis.

Details here: uwo.ca/ntp/blog/202...

#SKstorm

New Paper Alert! "Analysis of Forest-Based Tornadoes Using Treefall Patterns" in Monthly Weather Review, authored by our team at @cssl.ca and led by PhD candidate Daniel Butt. Based on this and other techniques, we may be able to re-rate some Canadian tornadoes.

journals.ametsoc.org/view/journal...

UPDATE: Two NTP teams will investigate wind damage, one in SE AB and one in central SK. The NHP will also have a team investigating hail damage in the Cassils / Brooks, AB area.

Please send significant damage reports to @ntp-reports.bsky.social and @nhp-reports.bsky.social. #ABstorm #SKstorm

There are numerous reports of significant wind damage in southeastern Alberta from intense storms earlier today. Hail damage has also been reported.

An NTP survey team will leave tomorrow for the area to thoroughly assess the damage.

Please send damage reports to @ntp-reports.bsky.social. #ABstorm

The Canadian Severe Storms Lab is excited to be a sponsor of the 41st AMS International Conference on Radar Meteorology in Toronto next week. Welcome to all those travelling from afar!

And it looks to be a stellar program - have a look here: www.ametsoc.org/ams/meetings...

#AMS41Radar

In Alberta’s ‘Hailstorm Alley,’ scientists-turned-storm-chasers look into the eye of the storm for answers Researchers from Western University aim to use data from hard-hit areas to help Canada better understand – and protect against – dangerous and costly hail damage

“Scientists-turned-storm chasers” are tracking down Alberta hail storms to better understand how to protect against them.
Researchers from the Canadian Severe Storms Laboratory ( @cssl.ca ) at #WesternU spoke with the @theglobeandmail.com about the Northern Hail Project.

It’s challenging to predict extreme thunderstorms — improving this will help reduce their deadly and costly impacts Current models for weather forecasting tend to ignore outlier data; learning how to incorporate these can help reduce risk and increase community resiliency.

Follow the link below to a new article on the detection and prediction of 'extreme' thunderstorms by Drs. Sills and Kopp of the Canadian Severe Storm Laboratory. Published in The Conversation (Canada). Let us know what you think!

theconversation.com/its-challeng...

Spark had the best rainy day with the Canadian Severe Storm Lab. Guests got to learn how the Northern Hail Project team tracks down the perfect #storm and the tools used to get hail data!

They also showed off their storm-chasing vehicles and surveillance drones. ⛈️

Thanks for coming @cssl.ca!

Hail damage across Calgary has teams documenting the fallout - The Weather Network Researchers from Western University are closely examining the damage caused by a hailstorm in Calgary on July 13 to improve preparations for this recurring type of event. Connor O'Donovan reports.

Calgary has a long history of intense hailstorms, and this summer is no different.
@weathernetwork.bsky.social spoke with #WesternU hail researcher Matthew Woodward, who is on the ground documenting damage from a recent storm for @cssl.ca