Coming
soon.

What RRFS is

The Rapid Refresh Forecast System is NOAA's next convection-allowing model: a single hourly-updated system on a 3 km grid covering all of North America, built on the FV3 dynamical core. On October 6, 2026 it becomes operational at the National Centers for Environmental Prediction and retires the NAM, HiresW, HREF and SREF in the same day, unifying the storm-scale suite into one model.

Where the hourly HRRR stops at 18 hours and its four synoptic runs at 48, RRFS reaches 84 hours from the 00, 06, 12 and 18Z cycles. Alongside the deterministic run, five ensemble members with different initial conditions, boundary conditions and physics run to 60 hours. The RRFS Ensemble Forecast System (REFS) blends those members with the previous cycle, and over the CONUS and Alaska adds two HRRR members, to produce probability and spread products. HRRR itself stays in operation.

Replaces

NAM, HiresW (except the Guam domain), HREF and SREF, all retired on implementation day.

Keeps

HRRR and RAP continue. HRRR contributes two members to REFS over the CONUS and Alaska.

Output grids

3 km CONUS and Alaska, 2.5 km Hawaii and Puerto Rico, 13 km North America, plus sub-hourly 2-D fields.

Ensemble products

Mean, spread, probability-matched mean, probabilities, ensemble-agreement-scale probabilities, flash-flood exceedance (CONUS).

Data feed

Parallel feed on NOMADS since August 11, 2026; production paths under rrfs/prod and refs/prod from October 6.

Next

Version 2, on the MPAS dynamical core, is planned for 2027–2028.