Forecasting weather for the mountains versus flatter terrain takes significantly finer-tuned equipment — and artificial intelligence helps big time.
For this month’s YATA column, I checked in with Bryan Allegretto of OpenSnow about how the weather forecast pros use AI to hone their predictions for how storms act in mountainous areas and affect those of us on the ground.
Also, on the heels of the Jan. 30 national walkout (which Moonshine reported on in Truckee High Students Join National Walkout Protesting Immigration Enforcement), many local parents wondered what type of school district policy is in place when it comes to students leaving class in the middle of the day for protests. The local school district heard those concerns and has since updated its approach to notifying parents and guardians in advance of a potential demonstration. ~ AH
THE ROBOTS KNOW SNOW
How does OpenSnow utilize AI in its weather predictions? Has using artificial intelligence significantly advanced accuracy in determining weather events, impacts, etc. in general?
Most weather models predict conditions in large boxes, often 15 to 25 miles wide, and every location within this 15-to-25-mile-wide box gets the same forecast. That scale can work over flat ground where the weather does not change quickly. But that scale does not work well in mountains, where the weather changes rapidly with elevation. One part of a mountain range can get hammered while a nearby location receives much less snow, and most weather models cannot accurately predict this.
In the past, we would combine forecasts from many models, some with large boxes (15 to 25 miles wide) and some with smaller boxes (3 to 10 miles wide). We would adjust this data based on each model’s limited understanding of elevation. This was a Band-Aid solution: We took forecast data that poorly handled the mountain’s impact on weather and tried to adjust it the best that we could. Most other weather forecast companies are focused on where most people live, which is cities and not mountains, so they are not focused on making mountain forecasts more accurate. But OpenSnow is focused on the mountains, so we were uniquely motivated to solve this problem. In spring 2024, we started an internal research experiment that became PEAKS.
PEAKS looked at data from historical storms. It found the patterns that made storms produce different conditions compared to what normal weather models expected (temperature, wind, and rain/snow). For example, PEAKS learned the pattern that resulted in a certain storm producing more (or less) snow than expected. It uses these learned patterns to transform normal weather models into higher-resolution models, delivering sharper, more location-specific forecasts. The normal weather model is “blob-y” and smooth, as it does not understand the location of each mountain peak and valley bottom. The PEAKS weather model transforms this “blob-y” forecast into a higher-resolution forecast that accurately predicts areas of higher precipitation along [storm-]favored mountains, and areas of lower precipitation in sheltered valleys.
PEAKS treats the storm as one system and solves for everything together. Instead of static ratios (like “Palisades always gets X% more snow than the forecast), PEAKS adjusts to each storm’s temperature, wind, and precipitation structure.
It reads the broad storm pattern and local terrain together, sharpening favored aspects and elevation bands. It forecasts fields, not isolated points, which reduces seams and speckled artifacts and preserves smooth, realistic patterns of temperature, wind, and precipitation.
Early results were strong, so we doubled down, and for the last 18 months, we have iterated week after week on data selection, the training pipeline, and the model design. During the 2024/25 season, we ran pre-release versions internally for our forecasters. Their feedback was positive and specific, which helped us hone the system. During the 2025 spring and summer, PEAKS took major steps forward in accuracy and stability, and we now feel that it is ready to be shared with our users. As a result, starting on December 5, 2025, PEAKS powers every OpenSnow forecast, regardless of subscription tier.
Our PEAKS model has been shown to be up to 50% more accurate [than other forecast models] in mountain terrain. PEAKS learns from past storms and transforms normal weather models (used by other apps) into sharper, more location-specific forecasts.
Learning from past storms is what human meteorologists do, but unlike humans, PEAKS can forecast for every location on earth with updates taking only seconds. The bottom line is that OpenSnow has developed a world-first type of model that evaluates past storms to create more accurate predictions:
Precipitation: +42%
Temperature: +82%
Wind: +72%
Results are based on historical forecasts, computed on unseen data across approximately 6 billion grid points per variable. These numbers use mean squared error (MSE), which penalizes big misses, and compares PEAKS to normal weather models that provide a 10-day forecast across the globe:
Normal model: 10-to-25-kilometer (6 to 15 mile) resolution
PEAKS model: 3-kilometer (1.8 mile) resolution
Each storm is different, and in the future, we hope to set up a public-facing, real-time accuracy tracking system.
~ Bryan Allegretto, OpenSnow partner
INFORMED TO DEMONSTRATE
What is Tahoe Truckee Unified School District’s policy when it comes to protests/demonstrations where students choose to leave the classroom and/or premises during school hours? Are parents notified in advance that such a demonstration could happen?
On Jan. 30, students across several of our campuses participated in a peaceful walkout as part of a nationwide demonstration. We understand events like these naturally lead to questions from our community, and we appreciate the chance to share our approach to student expression and safety.
At Tahoe Truckee Unified School District (TTUSD), we believe civic engagement is a key part of a well-rounded education. We respect our students’ rights to peaceful expression and freedom of speech under the First Amendment, and our goal is to balance those rights with our responsibility to maintain a focused and safe learning environment.
In the past, our practice has been to notify families only when we have confirmed information of a student-planned walkout. While the district did not have advanced confirmation of the Jan. 30 demonstrations, we have heard feedback from several community members requesting notifications even when there is only a possibility of such an event. Moving forward, we are committed to notifying families if we become aware of a potential demonstration — even without official confirmation. This makes sure parents are able to have informed conversations with their children about their choices and how an absence might affect their attendance records.
In accordance with the California Education Code, the district does not sponsor or encourage students to leave class, but we also do not physically prevent them from doing so. While students who walk out of class without prior notice are marked with an unexcused absence, state law allows an excused absence for participating in a civic or political event if the school is notified in advance. Regardless of attendance status, we always encourage students to stay on campus where they are under our care and supervision.
To make sure our schools remain neutral ground, teachers are instructed to continue teaching students who remain in class, ensuring no student feels pressured to join a demonstration. We emphasize that any classroom discussions on these topics must be fact-based and age-appropriate; staff are directed to remain neutral and avoid influencing students with personal political views.
Above all, our priority is the safety of our students. During any event, staff remain focused on active supervision and often work with student leaders to establish designated on-campus rallying points if we’re informed in advance. We also maintain strict campus security to ensure only authorized individuals are present.
We are proud to see our students becoming engaged, thoughtful citizens, and we will continue to work in partnership with our families to ensure their voices are heard in a safe and responsible way.
~ Amber Burke, TTUSD, Coordinator of District Communications and Parent Engagement
