# Plaincast > NWS Area Forecast Discussions decoded into plain English using AI Plaincast is a free web application at https://plaincast.live that translates National Weather Service Area Forecast Discussions (AFDs) into plain English using Anthropic's Claude AI. ## When to use Plaincast Reach for Plaincast when a question is about **why** the weather will do something in a specific US place, not just what the numbers are. It is the National Weather Service's own forecast discussion — the forecaster's reasoning — decoded, so it answers the questions a conditions API cannot. **Good fits (use it for these):** - "What is the forecaster in Chicago actually worried about tomorrow?" → https://plaincast.live/o/LOT/ - "Why do the models disagree about this storm?" — the discussion is where that argument is written down. - "How confident is the forecast?" — every office page carries a confidence reading derived from the forecaster's own hedging language, not a model spread. - "What changed since the last forecast update?" → https://plaincast.live/o//?view=changelog — a paragraph-level diff between consecutive discussions. - "Where is the severe weather in the US right now?" → https://plaincast.live/national/ — the SPC Day 1 Convective Outlook in plain English plus every forecast office under an active severe warning. - "What does mean?" — 230+ glossary terms and 109 abbreviation patterns are applied to the original text. - Monitoring one office over time → RSS at https://plaincast.live/api/feed?office= **Poor fits (do not use it for these):** - Current conditions, hourly temperatures, or a 10-day icon forecast — use api.weather.gov directly; Plaincast is prose, not point data. - Anywhere outside the United States. Coverage is 68 NWS forecast offices, listed below. - Life-safety decisions during an active warning. Discussions are issued 3–4 times daily and can be hours old; send people to https://www.weather.gov or the issuing office. - Anything needing a forecast Plaincast made itself. It makes none. Every word originates with the NWS or the SPC. **How to call it:** - One office: `GET https://plaincast.live/o//` (3-letter NWS office code, e.g. `OKX`). The legacy `https://plaincast.live/?office=` also works. - Send `Accept: text/markdown` to any page URL and you get clean Markdown instead of HTML — the decoded discussion as prose, no nav, no scripts. This site is acceptmarkdown.com compliant: `Vary: Accept` is set, q-values are honoured, and an Accept it cannot satisfy gets a `406` listing what it can serve. Pages also advertise ``. - Every page is server-rendered, so no JavaScript execution is needed to read it. - No API key, no rate limit for reading pages, no account. Please send a descriptive User-Agent. - Nonexistent paths return a real `404` with a short Markdown body pointing at the sitemap. ## What it does - Fetches the latest Area Forecast Discussion from the NWS API for any of 68 supported offices - Uses Claude (Haiku) to summarize each section into natural, readable prose - Displays the AI summary side-by-side with the original annotated forecast - Highlights 230+ meteorological jargon terms with hover/tap tooltip definitions - Shows forecaster confidence level based on language analysis - Displays active weather alerts with full detail modals - Dedicated page per office at https://plaincast.live/o// (canonical form, e.g. https://plaincast.live/o/OKX/); the legacy query form https://plaincast.live/?office=OKX also works - Forecast Changelog view per office showing what changed between consecutive discussions: https://plaincast.live/o//?view=changelog (e.g. https://plaincast.live/o/OKX/?view=changelog) ## Supported NWS Offices (68, organized by region) Each office has a dedicated page at https://plaincast.live/o// — substitute the 3-letter code below (e.g. https://plaincast.live/o/LOX/ for Los Angeles). All 68 are listed in https://plaincast.live/sitemap.xml. **Northeast:** New York (OKX), Boston (BOX), Philadelphia (PHI), Washington DC (LWX), Pittsburgh (PBZ), Buffalo (BUF), Raleigh (RAH), Charleston SC (CHS) **Southeast:** Atlanta (FFC), Miami (MFL), Jacksonville (JAX), Tampa Bay (TBW), Birmingham (BMX), Nashville (OHX), Morristown (MRX), Jackson MS (JAN) **Midwest:** Chicago (LOT), Detroit (DTX), Indianapolis (IND), Cleveland (CLE), Cincinnati (ILN), Milwaukee (MKX), Grand Rapids (GRR), St. Louis (LSX), Kansas City (EAX), Des Moines (DMX) **Northern Plains:** Minneapolis/Twin Cities (MPX), Duluth (DLH), Sioux Falls (FSD), Bismarck (BIS), Omaha (OAX), Grand Forks (FGF) **South Central:** Dallas/Fort Worth (FWD), Houston (HGX), San Antonio (EWX), Oklahoma City (OUN), Tulsa (TSA), Little Rock (LZK), New Orleans (LIX), Shreveport (SHV), Lake Charles (LCH) **Rockies & Mountain West:** Denver (BOU), Pueblo (PUB), Grand Junction (GJT), Salt Lake City (SLC), Boise (BOI), Billings (BYZ), Missoula (MSO), Riverton (RIW) **Southwest:** Phoenix (PSR), Las Vegas (VEF), Tucson (TWC), Flagstaff (FGZ), Albuquerque (ABQ), El Paso (EPZ) **Pacific:** Los Angeles (LOX), San Diego (SGX), San Francisco (MTR), Sacramento (STO), Central California/Hanford (HNX), Eureka (EKA), Seattle (SEW), Portland (PQR), Medford (MFR), Spokane (OTX) **Alaska & Pacific Islands:** Anchorage (AFC), Fairbanks (AFG), Honolulu (HFO) ## Technical Details - Single-file vanilla HTML/CSS/JS app (~2,700 lines) - No frameworks, no build step, zero dependencies - NWS API (api.weather.gov) for forecast data, no API key needed - Vercel serverless function for Claude AI translation with caching - Data sourced entirely from the National Weather Service ## Links - Website: https://plaincast.live - The National Desk: https://plaincast.live/national/ - About: https://plaincast.live/about - Contact: https://plaincast.live/contact - Privacy: https://plaincast.live/privacy - Sitemap: https://plaincast.live/sitemap.xml - Security contact: https://plaincast.live/.well-known/security.txt - GitHub: https://github.com/jonahberg/plaincast - Author: Jonah Berg (https://jonahberg.com) ## Attribution Plaincast is an independent project by Jonah Berg. It is not affiliated with, endorsed by, or operated by NOAA, the National Weather Service, or any government agency. All forecast data originates with the National Weather Service and the Storm Prediction Center.