The Spread
40404050505050505050506060606060606060606060607070707070707070808080808080°Oklahoma City: 80 °F at 12Z 9 Sep60°Salt Lake City: 60 °F at 12Z 9 Sep55°Seattle: 55 °F at 12Z 9 Sep78°Orlando: 78 °F at 12Z 9 Sep73°New York: 73 °F at 12Z 9 Sep84°Los Angeles: 84 °F at 12Z 9 Sep68°Chicago: 68 °F at 12Z 9 Sep80°Houston: 80 °F at 12Z 9 Sep93°Phoenix: 93 °F at 12Z 9 Sep83°Dallas: 83 °F at 12Z 9 Sep72°Atlanta: 72 °F at 12Z 9 Sep64°Boston: 64 °F at 12Z 9 Sep67°Washington: 67 °F at 12Z 9 Sep61°Denver: 61 °F at 12Z 9 Sep64°Minneapolis: 64 °F at 12Z 9 Sep85°Miami: 85 °F at 12Z 9 Sep67°San Francisco: 67 °F at 12Z 9 Sep80°New Orleans: 80 °F at 12Z 9 Sep71°Buffalo: 71 °F at 12Z 9 Sep67°Charlotte: 67 °F at 12Z 9 Sep70°Philadelphia: 70 °F at 12Z 9 Sep70°Detroit: 70 °F at 12Z 9 Sep79°Tampa: 79 °F at 12Z 9 Sep76°San Diego: 76 °F at 12Z 9 Sep78°St. Louis: 78 °F at 12Z 9 Sep79°San Antonio: 79 °F at 12Z 9 Sep

One NOAA AIGFS run — issued 12Z 9 Sep — played forward 6 hours at a time, from its analysis to 384 hours out.

Methodology

Nights and days pass as you step this run: that motion is the weather the run forecasts, not the forecast changing. Forecast Evolution is the other film — it holds one moment still and steps the runs, so the only thing that moves there is the model's mind. The colour scale is fitted to the whole run at once, so the same moment reads with more bands here than on the static NOAA AIGFS map; the field is identical. Six-hourly to 384 hours — as far as this centre's run is held, which is not the same on all four temperature films: each states its own here. The frames past the one shown load on demand.

Every map on this page is drawn from model output we store ourselves, not from anyone's picture of it. The per-city read of the same day — which cities the models are fighting about, and what the discussion makes of it — is on the national page.