Adding Timing to Storm Forecasts

Define onset, peak, and tapering phases so your audience knows exactly when to expect it.

Why Timing Matters

"How much?" is only half the question. Your audience also needs to know when. Timing breakdowns help people plan — when to leave work early, when to start plowing, when conditions improve.

Timing Phases

For each region in a storm forecast, you can define up to three timing phases:

Onset

When precipitation begins. Set a date and time (e.g., "Thu 6 PM"). This tells your audience when conditions start to deteriorate.

Heaviest

When the most intense precipitation occurs. Can be a time range (e.g., "Thu 2 AM – 8 AM"). This is when accumulation rates are highest.

Tapering

When precipitation winds down and conditions improve. Set a date and time (e.g., "Thu noon"). This tells your audience when the worst is over.

Tips for Effective Timing

Be specific — "Thursday evening" is good. "Thu 6 PM" is better.

Use ranges when uncertain — "Thu 2-8 AM" is more honest than a single time when you're not sure.

Update as the event approaches — Timing is the most volatile part of a forecast. Edit and republish as your confidence increases.

Pair with your narrative — Use the narrative field to explain timing uncertainty and what could shift the timeline.

How Timing Displays

On the forecast detail page, timing appears as a visual timeline for each region — showing onset, peak, and tapering as connected phases. This makes it easy for your audience to scan and understand at a glance.