Station Tables

• Columns: 2-m temperature and dewpoint (°F), mean sea-level pressure (mb), 850-mb temperature (°C), 700-mb relative humidity (%), 6-hour precipitation ending at the valid time (inches), 6-hour snowfall and the running snowfall total (inches), 500-mb height (dam) and 1000–500 mb thickness (dam).
• HRES is the IFS deterministic run (open-data stream “oper”) at 0.25°. It updates four times a day: the 00Z and 12Z runs go out to 240 hours (10 days), and the 06Z and 18Z runs to 144 hours (6 days).
• ENS uses the 50 perturbed members (the control run is not in the open-data ensemble files). Text values are the mean with the standard deviation in parentheses. The table also shows the 10th–90th percentile range, and the share of members with 0.25″ or more in 6 hours.
• Other models: GFS (0.25°, all four cycles) and GEFS (0.5°, 31 members, all four cycles) from NOAA; AIFS Single from ECMWF open data (all four cycles; its 700-mb RH is computed from specific humidity because AIFS open data has no RH); GDPS (15 km, 00Z/12Z) and the 10 km RDPS (RGEM, all four cycles to 84 h; Hawaii is outside the domain) and GEPS (21 members, dewpoint computed from temperature and RH) from Environment and Climate Change Canada at 00Z and 12Z; ARPEGE (0.25° global, all four cycles to 102 h, Hawaii in domain) from Météo-France under the Etalab Open Licence 2.0, unofficial; and ICON global from Deutscher Wetterdienst, which ends at 180 h on its 00Z/12Z runs and 120 h on 06Z/18Z; and the UK Met Office global model (UKMET, 10 km) from Met Office open data on AWS, 00Z and 12Z only, which ends at 168 h (its 06Z/18Z runs stop at 69 h). UKMET 6-hour precipitation is the sum of the Met Office’s hourly, 3-hourly or 6-hourly totals. All are capped at 240 h.
• Snowfall: snow = model snowfall water equivalent × 10:1 (1″ of melted snow = 10″ of snow). ECMWF HRES, ENS and AIFS use their snowfall field (sf); GDPS, RDPS and GEPS use ECCC’s total snow precipitation; ICON adds its grid-scale and convective snowfall. UKMET’s open data has no snowfall amount, so its snow is also an estimate: each hourly (to 54 h), 3-hourly (to 144 h) or 6-hourly precipitation total × the share of the Met Office’s precipitation rate falling as snow (large-scale + convective) at the end of that period. GFS and GEFS publish no snowfall amount, so theirs is an estimate: 6-hour precipitation × the share of those 6 hours the model’s categorical precipitation type is snow. Totals are a running sum from the start of the run, so they ignore melting and settling. Ensembles show the member mean and the share of members with a total of 1″ or more.
• Values are interpolated bilinearly from each model’s grid to each station (ICON uses the nearest grid cell). Grid cells blend land and water, so coastal stations can run a little off.
• New HRES runs post around 2:35 AM (00Z), 7:30 AM (06Z), 2:35 PM (12Z) and 7:30 PM (18Z) Eastern. The ensemble posts around 2:40 AM and PM.

Source: ECMWF open data, © European Centre for Medium-Range Weather Forecasts (ECMWF), licensed under CC BY 4.0. Changes: interpolated to stations, unit-converted, and summarized by Milton Climate. ECMWF does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use.

Other sources: NOAA/NWS/NCEP (public domain); Data Source: Environment and Climate Change Canada (ECCC Data Servers End-use Licence); Data basis: Deutscher Wetterdienst, own processing (DWD terms, CC BY 4.0). Changes: interpolated to stations and unit-converted by Milton Climate.

UKMET: Contains Met Office data, British Crown copyright, licensed under CC BY-SA 4.0 (Met Office global deterministic open data). Changes: interpolated to stations, unit-converted and 6-hour precipitation summed by Milton Climate; the UKMET tables are shared under the same CC BY-SA 4.0 licence.