What is an Area Forecast Discussion (AFD)?

An Area Forecast Discussion is a detailed narrative forecast written 3-4 times daily by National Weather Service meteorologists. Unlike weather apps that show icons and numbers, AFDs explain the reasoning behind the forecast - why models disagree, what forecasters are watching, and where uncertainty exists.

How does Plaincast translate NWS forecasts?

Plaincast uses Anthropic's Claude AI to summarize each forecast section into natural, readable prose. It also annotates the original text with a 230+ term jargon glossary, converts Zulu (UTC) times to local time zones, and highlights key information for quick scanning.

Which NWS offices does Plaincast support?

Plaincast supports 68 NWS forecast offices across all US regions including Los Angeles (LOX), New York (OKX), Chicago (LOT), Houston (HGX), Phoenix (PSR), San Francisco (MTR), Miami (MFL), Seattle (SEW), Denver (BOU), and many more.

Yes, Plaincast is completely free and open source. It uses the NWS public API for forecast data and Anthropic's Claude for AI summaries. No account or API key required.

How often are forecasts updated?

NWS meteorologists issue new Area Forecast Discussions 3-4 times per day, typically around 4 AM, 10 AM, 4 PM, and 10 PM local time. Plaincast automatically fetches the latest discussion when you load the page.

Honolulu NWS Forecast in Plain English

What is an Area Forecast Discussion?

Area Forecast Discussions are the real forecasts, written 3 to 4 times daily by NWS meteorologists reading the models and interpreting what they mean for your area. They offer far deeper insight than any weather app, but they're written in dense meteorological shorthand. Plaincast uses Anthropic's Claude to summarize them into plain English, side by side with the annotated original.

Area Forecast Discussion · National Weather Service Honolulu (HFO) · issued Sunday, August 23 at 9:12 AM HST.

Revised in 12 passages since the 3:59 AM discussion. See every revision.

Synopsis

Locally strong and gusty trade winds will prevail today as Tropical Storm Moke moves westward, several hundred miles south of the islands. Moisture along the northern periphery of Moke will bring wet conditions and a risk of flash flooding on the Big Island through Monday, while less rainfall is expected to impact windward sections from Maui to Kauai over the next couple of days. Trade winds will gradually ease Monday and Tuesday as Moke moves westward away from the area, with drier trade wind weather returning midweek.

This is the plain-text edition, decoded without AI so it loads anywhere. The full Plaincast experience — plain-English summaries beside the annotated original, with the forecast changelog — loads automatically with JavaScript, or open the interactive edition.

Honolulu (HFO) — the National Weather Service forecast in plain English · Plaincast

Synopsis