Hail, wind, lightning and more: who's watching your array?
Severe hail can total millions of dollars in panels in minutes. SiteWarn™ puts live meteorologists on your exact array boundary 24/7/365 and warns your O&M team of hail-capable storms, lightning and high wind — with the lead time you need to stow, clear crews or de-energize before impact.
Trusted for 14 years at more than 400 sites in all 50 states, with a 100% client renewal rate.
Customized for a single site — or for a command or operations center monitoring hundreds, even thousands, of sites from one screen.
Why solar owners and O&M teams choose SiteWarn
A fully customized program: you set the thresholds, we watch the weather.
Hail alerts in time to stow
We give your O&M team advance warning on hail-capable storms approaching your array — with enough lead time to drive trackers to stow position before impact — then follow the storm and tell you when it's safe to return to tracking.
Specific to your array boundary
Instead of warnings drawn around whole regions, we monitor your exact array footprint so you only stow, dispatch or de-energize when there's a real threat to your site. When an NWS polygon includes your site but your array is clear, you get a null-warning notification and stay in production.
Lightning and wind warnings the NWS won't give you
The National Weather Service issues no warnings for cloud-to-ground lightning, and its wind thresholds aren't site-specific. We alert you to lightning within your custom radius and to winds above the limit your trackers and crews require.
Alerts your way, unlimited users
Web portal, app, email, text or push, phone (live or recorded) — or straight into your SCADA, tracker control or O&M platform by API — to O&M, control room, asset management and field staff. Interactive radar with your array footprint mapped, at no extra cost per user. Portfolio programs cover every site with per-site thresholds and a group rate.
What a typical solar program looks like
Every program is built with you. Here is a common starting point for a single utility-scale site; a portfolio program repeats this per site with the thresholds each one needs.
- Hail: warning on any hail-capable storm forecast to reach the array boundary, issued 45 minutes ahead (adjusted to your stow time), with updates and an all-clear.
- Lightning: alert on cloud-to-ground strikes within 10 miles, warning within 5 miles, all-clear 30 minutes after the last strike inside the warning radius.
- Wind: warning when sustained winds or gusts at the site are expected to exceed your tracker stow threshold — for example, 45 mph.
- Tornado and severe thunderstorm: site-specific warnings when your array is in the storm's path; null-warning notification when the NWS polygon includes you but the threat does not.
- Flooding, wildfire and winter weather: added where your site's exposure calls for it.
- Wildfire: advisory when fire-weather conditions are expected to threaten the site or its access routes; warning when an active fire's location and expected spread put the site at risk, with timing and an all-clear.
- Heat (WBGT): advisories and warnings at your work-rest thresholds for field crews, on Wet Bulb Globe Temperature or heat index.
- Hazard Matrix for portfolio operators: your arrays grouped into regions you define, with each region's status for every hazard — hail, lightning, wind, wildfire — on one grid, for the central O&M or asset-management desk.
- Delivery: push alerts and a live phone call to the O&M lead, text and email to field crews, portal access for the control room and asset manager — and an API feed into the tracker control or monitoring platform to trigger stow automatically if you choose.
Take the one-page overview with you
Everything on this page on a single sheet — the hail, lightning and wind problem for solar, how SiteWarn is configured for an array, and how to start a Free Live Trial. Made to forward to your O&M lead, asset manager or safety committee.
What a stow warning looked like at one Texas site
From a utility-scale solar operator's own account of a severe weather event.
"A band of severe thunderstorms capable of producing wind gusts up to 55 mph with a history of hail and tornadoes was approaching one of our sites in Texas. This facility has a documented history of tripping offline during high-wind events, making proactive stowing essential to prevent equipment damage and unplanned outages."
"Upon receipt of the severe weather alarm from WeatherGuidance, we immediately initiated a wind stow to mitigate the impending wind and hail risk. The site achieved full stow prior to impact. Shortly thereafter, feeder 1 tripped offline; however, because all trackers were already in the stowed position, the panels remained protected, and no exposure occurred."
"Once the storm cell cleared and site conditions were safe, we coordinated restoration activities. The feeder was successfully reclosed, the site was unstowed in a controlled manner, and the facility was returned to normal production with zero production loss."
"Proactive storm warnings from WeatherGuidance prevented equipment damage and enabled an efficient post-event restoration with minimal risk exposure. We truly appreciate your valuable service!"
Operations team, utility-scale solar plant operator, Texas
Full stow before impact. Feeder trip with no panel exposure. Controlled unstow and zero production loss. That sequence is what a SiteWarn program is built to produce.
Questions solar operators ask
How much lead time can you give before hail reaches the array?
Lead time is set with you based on how long your trackers take to reach stow — 30 to 60 minutes is common. We warn on hail-capable storms approaching your array boundary, follow up as the storm evolves, and issue an all-clear so you're not sitting in stow longer than necessary.
Do you warn for lightning?
Yes. The National Weather Service issues no warnings for cloud-to-ground lightning. SiteWarn alerts you to strikes within a custom radius of your array so field crews can clear the site before the first strike, and tells you when it's safe to resume work.
Can you warn on wind speeds specific to our tracker limits?
Yes. You set the wind threshold at which trackers must stow or crews must stop, and we warn when winds at your site are expected to exceed it.
Can one program cover our whole portfolio?
Yes. Multi-site programs cover every array with per-site thresholds, group pricing, and unlimited users across O&M, asset management and the control room. Single-site programs start at $99.95 a month; multi-site discounts apply — ten sites does not cost ten times one.
What does the Free Live Trial involve?
We set up your real array, thresholds and delivery methods and monitor it exactly as we would for a paying client — no credit card and no obligation. Most sites are live the same day; overnight requests are set up the next morning.
See it live before the next hail season
Not a demo. We set up your real array with your real stow thresholds and monitor it exactly as we would for a paying client.
- Live hail, lightning and wind warnings for your actual site
- Your thresholds, lead time and delivery methods
- Portal, app and radar access for O&M and control room — API available for integration
- No credit card, no contract, no obligation
Prefer to talk first? Call (512) 504-3151 or email sitewarn@weatherguidance.com during business hours, and we'll get right back to you.