Enter a ZIP and everything here recenters: every free weather station out to 300 miles, the Pacific buoys upstream, the jet stream overhead, the air headed your way, and a forecast for that exact spot built from 7 models and 82 ensemble members, nudged to the nearest stations.
Jet: the strongest 250 hPa wind in the 7 by 7 box and where that axis sits relative to you. 500 hPa: the height over you against the box average (a ridge is warmer and drier, a trough colder and stormier). Steering: the 700 hPa wind, the level that carries Sierra storms. Moisture: 700 hPa humidity in the cone upstream of you. Snow level: freezing level minus 1,000 ft, a display heuristic.
The Kerr Mesonet pulls every free, public station around Truckee out to 300 miles every 10 minutes: ASOS and AWOS airports, Caltrans and NDOT road sensors (air and pavement temperature), DCP gauges including the RAWS fire weather network and snow sensors, SCAN and USCRN reference stations, NOAA buoys and coastal stations in the eastern Pacific, and NRCS SNOTEL snow sites. A station more than 3 hours old is dropped. A temperature far off the regional lapse line is flagged suspect and kept out of the leaders.
Weather moves with the wind at about 700 hPa (roughly 10,000 ft). Stations in the cone that wind comes from are upstream of you; what they report now is what is headed your way. When that wind is light, west is used, because that is where Sierra storms come from.
Seven models (NBM, HRRR, ECMWF, GFS, ICON, GEM, JMA) are read for the exact point, each downscaled to its elevation. The consensus weights the National Blend twice and HRRR one and a half times for the first two days, and every model's own number is shown beside it. The first six hours are nudged toward the nearest quality stations within 20 miles and 1,000 ft of elevation. The odds come from 82 ensemble members (GEFS and ECMWF).
No. The engine on /weather is a learned blend verified nightly against the Truckee airport, and it stays the headline forecast for Truckee. This page is the regional consensus for any place, with the station network and the jet stream around it. The two should agree most days; when they do not, the verified engine wins for Truckee.