Sea Surface Temperature
Sea Surface T Anomaly
Precipitation & Clouds
Mean Sea Level Pressure
Sea Ice & Snow
The weather maps shown here are generated from the NCEP Global Forecast System (GFS) model. GFS is the primary operational model framework underlying U.S. NOAA/NWS weather forecasting. The model is run four times daily on a global T1534 gaussian grid (~13 km) to produce 16-day forecasts. Here, we use 0.25°x0.25° (~30 km) output grids available from NOMADS, and calculate daily averages from eight 3-hourly timeslices starting at 0000 UTC.
* 2/23/2016 — NEW GFS MODEL BIAS CORRECTION FACTORS calculated from winter (DJF) GFS-CFSR estimates: 0.7 (World), 0.75 (Northern Hemisphere), 0.5 (Southern Hemisphere), 1.1 (Arctic), 1.0 (Antarctic) and 0.5 (Tropics). GFS model bias appears to vary with the seasons due to snow/ice and albedo processes, and therefore season-specific correction terms will be applied from now on. As stated below, refer to the CFSR/CFSV2 Daily Reanalysis Maps interface for the most reliable daily temperature anomalies. CFSR/CFSV2 daily reanalysis maps are updated once or twice per month.
Note that bias-corrected GFS-CFSR temperature anomalies will differ slightly from those calculated from CFSV2-CFSR (see these comparisons for June 30, 2015). CFSV2-CFSR is apples-to-apples; therefore, difference maps within the Daily Reanalysis Maps image archive should be considered reliable, and take precedent over the GFS-CFSR anomaly maps shown here as part of the current 7-day forecast.
See this NCEP/NWS discussion for additional information on model bias.