What is new​

• Instant forecast checks on change — creating, importing, moving, or re-enabling a location checks it against the latest forecast right away, alongside the watch, warning, advisory, and outlook checks that already ran instantly.
• Moved locations re-checked immediately — move a location and it picks up the forecast for its new spot on the same change, not the next cycle.

Behind the scenes​

Forecast storage moved to a shared weather-grid model: locations that fall on the same forecast grid cell now share one stored value instead of each keeping its own copy. That speeds up every forecast cycle and sets the stage for coverage beyond the lower 48.

There is nothing to turn on. Add or edit a location on the Locations page and its forecast rules take effect immediately.

What is new​

• Instant evaluation on change — creating, importing, moving, or re-enabling a location evaluates it against all currently-active hazard polygons immediately. If it is already inside a warned area, the alert fires right away.
• Move out, get an all-clear — moving a location out of a warned area sends an all-clear noting it is no longer in the warned area.
• Move back in, the alert reopens — the original alert reopens with its history preserved, rather than starting a brand-new one.
• No flapping — a location sitting near a warning edge is capped at one movement notification every 15 minutes per alert, so quick back-and-forth movement will not flood you.

One caveat​

Forecast-threshold rules — like heat, wind, or snowfall — still evaluate on the next forecast update. Instant forecast checks are coming next.

There is nothing to turn on. Add or edit a location on the Locations page and it takes effect immediately.

Heat & humidity​

• Heat Stress (WBGT) — Wet Bulb Globe Temperature, the metric used for work/rest scheduling. Alert at or above the NIOSH reference points (82°F alert, 88°F exposure).
• Max Humidity and Min Humidity — daily relative-humidity extremes. Min Humidity at or below 15% is a common Red Flag / fire-danger criterion.

Precipitation​

• Precip Probability (12-hour) — chance of measurable precipitation in a 12-hour window.
• Total Precipitation — running 3-day accumulation through each forecast day.
• Excessive Rainfall Outlook (WPC) — categorical flash-flood risk (Marginal → High) for Days 1–5. The single best advance signal for flash flooding, often days ahead of any Flash Flood Watch.

Winter​

• Winter Precip Probability (WPC) — the chance that snow or ice reaches a threshold:
  • Days 1–3: snow ≥ 4 in, ≥ 8 in, ≥ 12 in, and ice ≥ 0.25 in (Slight / Moderate / High probability bands)
  • Days 4–7: extended-range probability of ≥ 0.25 in of snow or sleet (10–90%)

Tropical​

Populated whenever the National Hurricane Center has an active system affecting your locations:

• Threat levels — hurricane Wind, Storm Surge, Flooding Rain, and Tornado threat (None → Extreme).
• Wind probabilities — chance of tropical-storm-force (34 kt), 50 kt, and hurricane-force (64 kt) winds.

Fire weather​

• Dry Thunderstorm Outlook (SPC) — Isolated / Scattered dry-lightning risk, a leading cause of wildfire ignition, issued alongside the fire-weather outlooks.

To use any of these, open the Rules page, start a new rule, and choose the product under the forecast (NDFD) or outlook (SPC / WPC) rule types. Set your threshold and you're done — see the Forecast Products and WPC Outlooks guides for the full details.

Automatic, system-driven changes are labeled too — so a plan downgrade that disabled some locations, or a carrier opt-out on a phone number, shows up clearly rather than silently. The activity log is available to organization owners and admins.

For Storm Prediction Center outlooks the map draws the full risk picture: each category — Marginal, Slight, Enhanced, and up — in its own color, with the band over your location highlighted, so a "Slight Risk" alert actually looks like the day's outlook instead of a single shape. And when you tap the link in a text message it now unfurls as a rich preview on your phone — the map and a one-line summary — before you even open it.

To keep the signal clean, you control how often updates reach you, per rule: Escalations only (the default) notifies you when a warning gets more dangerous, All updates sends every change, and Off stays quiet until the all-clear. Times are shown in the warning's own local zone, and routine continuations that don't materially change anything no longer ping you at all.