

From orbit to the jobsite. Satellite, upper air, radar, eight forecast models and every live ground station nearby, blended every time this page loads and checked against what actually happened.
Writing today's note from live conditions…












Professional forecast model maps — switch models, parameters, and time steps
Live weather maps for Truckee, Lake Tahoe, and the Sierra Nevada including real-time Doppler radar, precipitation radar loop, wind speed and direction maps, temperature maps, cloud cover, thunderstorm tracking, snow depth, and GOES-18 satellite imagery. Our radar covers the Reno CWA (KRGX) with playable loops showing the last 3-6 hours of precipitation movement across I-80, Donner Pass, and the greater Tahoe Basin.
Radar (live loop) · Rain accumulation · Wind speed & gusts · Temperature · Cloud cover · Thunder & lightning · Snow depth · GOES-18 visible satellite · Infrared satellite · Water vapor · Pacific overview · NOAA radar (Reno CWA) · RainViewer animated radar · SPC severe weather outlook · Jet stream · QPF precipitation forecast · CPC 6-10 day temperature outlook · CPC 8-14 day precipitation outlook · ECMWF model viewer · GFS model viewer
Compare output from all 8 ensemble models — GFS, ECMWF, ICON, GEM (Canadian), JMA (Japan), UKMO (UK Met Office), CMA (China), and ECMWF-AI — across precip type, snow accumulation, temperature, wind, 500mb heights, jet stream, CAPE instability, total precipitation, and surface pressure. Step through individual forecast hours or animate the full run. Useful for tracking incoming Sierra storms 7-10 days out.
The season outlook and the latest NOAA El Niño numbers are written up in plain English in the Blog tab, dated to the NOAA update they come from, and refreshed when NOAA publishes a new one (second Thursday of each month). The seasonal and monthly maps above update themselves from NOAA.
Every layer this forecast is built from. Tap one to see it live.
errolkerr.com/weather is a free weather intelligence platform for Truckee, California and the Sierra Nevada, built by Errol Kerr. It combines eight global forecast models — ECMWF IFS, ECMWF AIFS, GFS, ICON, JMA, GEM, UKMO and CMA — into a single ensemble view with a 16-day extended forecast, real-time storm-cell tracking with approach ETAs, wildfire and smoke-direction alerts, 22 live Caltrans highway cameras along the I-80 corridor, upstream weather station data, USGS river streamflow readings, and 42+ interactive charts. The platform includes a self-learning back-checker that records forecast vs. actual conditions daily. Free forever, no signup required. Also see the GO/NO-GO crew weather decision tool and the storm forecast tracker.