How to read an NWS forecast discussion: a guide for restaurant managers

What a forecast discussion is

The National Weather Service has 122 local forecast offices covering the country. Each one publishes an Area Forecast Discussion (AFD) — a plain-text write-up of what the forecasters expect, why, and how sure they are. Offices issue a new discussion at least twice a day, usually early morning and mid-afternoon, and update it whenever the forecast changes.

The app on your phone takes the same forecast and boils it down to an icon. The discussion keeps the parts that matter for running a restaurant: when the rain arrives, how much, and how confident the forecasters are.

How to find yours

1. Go to weather.gov and search for your city.
2. On the forecast page, look for "Forecast Discussion" in the section for your local office — usually near the bottom of the page.
3. Bookmark it. The address looks like forecast.weather.gov/product.php?site=LOT&issuedby=LOT&product=AFD, where the three letters are your office (LOT is Chicago).

Each of our city weather pages links straight to that city's forecast discussion.

The sections, and which ones to read

Discussions are written for other meteorologists, pilots and emergency managers, so they're dense. You don't need all of it. Here's what each part is for:

• Key Messages (many offices include these at the top): the forecasters' own short summary. Start here — sometimes it's all you need.
• Synopsis: the big picture — fronts, high and low pressure, what's moving in.
• Short Term / Near Term: today through the next day or two. This is your staffing section. Look here for timing words.
• Long Term: roughly three to seven days out. Good for planning the week's schedule and big events, with less certainty.
• Aviation: written for pilots, but it gives hour-by-hour timing of rain and storms at the nearest airport — handy for "will it rain before 6 p.m.?"
• Watches, Warnings and Advisories: anything official in effect. Read this every time.

Words worth watching for

Confidence

This is what the app can't show you. "High confidence," "models in good agreement" and "likely" mean plan for it. "Uncertainty remains," "models diverge" or "low confidence" mean keep your options open — schedule an on-call shift rather than cutting staff.

Timing

Look for phrases like "late afternoon into the evening," "after midnight," "tapering off by midday," or "frontal passage around 21Z." Times ending in Z are in UTC: subtract 5 hours for Eastern Standard Time, 6 for Central (one hour less during daylight saving time). 21Z is 4 p.m. Eastern or 3 p.m. Central in winter.

Jargon you'll see often

• Convection: showers and thunderstorms.
• QPF: how much rain is expected (quantitative precipitation forecast).
• PoPs: probability of precipitation — the "40% chance" number.
• Diurnal: tied to the time of day, like summer storms that pop up in the afternoon heat and fade after sunset.
• FROPA: frontal passage — when the front, and the weather change that comes with it, moves through.

Our weather glossary has plain-English definitions of these and more, each with what it means for guest traffic.

An example, translated

Here's an illustrative example in the style of a real discussion:

What a dinner manager in a Central-time city should take from that:

• Lunch looks great — dry and low 70s. Open the patio.
• Storms arrive between 22Z and 01Z — 4 to 7 p.m. Central Standard Time, or 5 to 8 p.m. during daylight saving time — right as dinner starts. They might be an hour or two later, so the early-evening patio is a gamble.
• A quarter to half inch is in the range where foot traffic starts to drop — see how rain affects restaurant traffic.
• Gusty winds afterward mean the patio probably stays closed for the night even once the rain stops.
• Plan: full lunch staffing with the patio open, an on-call server for dinner, a takeout push mid-afternoon, and umbrellas down by 3:30.

Or let us read it for you

This is exactly what GuestFlow Weather does every morning: it reads your local office's latest forecast discussion and turns it into a short briefing — a HIGH, MIXED or LOW guest-traffic signal, what the weather will do, and what it means for your staffing and prep — in your inbox at 8 a.m. If the forecast changes during the day, you get an alert.