About Stormlio

National Hurricane Center (NHC) and Central Pacific Hurricane Center (CPHC)

Tropical cyclone advisories (TCP/TCD/TCM) and Tropical Weather Outlooks from both centers; NHC's Tropical Weather Discussions; best-track and forecast data; and GIS products: cone, track, wind radii, coastal watches & warnings, wind speed probabilities, wind arrival times and peak storm surge.

Weather Prediction Center (WPC)

Continues the full advisory suite (TCP/TCD/TCM) after a tropical cyclone moves inland and the National Hurricane Center hands it off — same storm, same advisory numbering.

Joint Typhoon Warning Center (JTWC)

Warnings and forecast tracks for the West Pacific, Indian Ocean and Southern Hemisphere. JTWC publishes no cone; the one we draw for its storms is derived by Stormlio — dashed on the map and marked beta on the storm page.

Model guidance and reconnaissance (ATCF, NCEP)

Model tracks from the ATCF forecast decks and NCEP's ensemble tracker (GEFS, and the Canadian and FNMOC ensembles), and aircraft reconnaissance fixes from the ATCF fix decks, along with satellite and radar fixes.

National Weather Service alerts

Active watches, warnings and advisories from the NWS alerts service, drawn on the map by their warning polygon, or by the counties or zones they name when they have none.

NWS / NDFD

The National Digital Forecast Database — the National Weather Service's gridded point forecasts for the United States.

ECMWF HRES

The European Centre's high-resolution global model, via its open-data release (licensed CC-BY-4.0). Used for global coverage, the forecast map layers, and as a second opinion alongside NDFD.

NOAA MADIS

Surface observations — METAR and one-minute ASOS stations, ships and buoys, and mesonets — via NOAA's Meteorological Assimilation Data Ingest System. Mesonet observations are made available to NOAA by their data providers, including the many state, agency and private networks aggregated by the University of Utah's MesoWest, and the Citizen Weather Observer Program. METAR station positions are checked against the NOAA Aviation Weather Center station list, and National Data Buoy Center metadata identifies the type of the buoys and coastal stations it lists.

Mesonet networks range from research-grade state and agricultural mesonets to volunteer citizen weather stations, so quality varies by network. NOAA does not own or operate mesonet sites and is not responsible for site maintenance or data accuracy. NOAA and its data providers disclaim liability of any kind whatsoever, including, without limitation, liability for quality, performance, merchantability and fitness for a particular purpose arising out of the use or inability to use the data.

Satellite and radar (NOAA NESDIS, NASA GIBS, NCEP)

GOES-East and GOES-West GeoColor imagery from NOAA NESDIS, GOES-East GeoColor from NASA's Global Imagery Browse Services (GIBS), and MRMS composite reflectivity radar from NCEP.

OpenStreetMap

The base map and place search use map data © OpenStreetMap contributors, available under the Open Database License.

Where both are available, the point forecast prefers NDFD while it is fresh and falls back to ECMWF HRES otherwise; each row is labelled with the source it came from. We never hide a gap behind an interpolated value — missing data renders as an explicit “—”.

A station's page shows only the sensors that station reports. Each value shows its own age, values that MADIS quality control questioned are marked, and values we calculate from other readings — such as dewpoint from temperature and humidity — are labelled as derived.