yanxingjianken/new_england_wx_mpas

New England 3 km MPAS — daily weather forecast

A daily, convection-permitting numerical weather prediction run over the northeastern United States, produced with MPAS-Atmosphere v8.3.1 and initialized from the operational NOAA GFS analysis. This dataset holds the post-processed forecast for the most recent run only — each new day's upload replaces the previous day's file.

What this is for

Mesoscale weather research and forecast verification over the Northeast corridor: the sea breeze at the coast, backdoor cold fronts, cold-air damming east of the Appalachians, coastal fronts, marine stratus, and boundary-layer mixing — the processes that control near-surface temperature (2 m) and its diurnal maximum/minimum. The forecast is intended to be compared against surface observations, satellite and radar.

Model configuration

Model	MPAS-Atmosphere v8.3.1 (global, non-hydrostatic)
Mesh	NCAR variable-resolution x20.835586 (835,586 cells), 60 km → 3 km, fine patch rotated to 40.63 °N, 74.09 °W
3 km core	~750 km radius — covers Boston, New York, Philadelphia and Washington at true 3 km
Initial conditions	GFS 0.25° analysis, 00 UTC cycle (global mesh — no lateral boundary conditions)
Time step	15 s · forecast length 22–30 h
Physics	convection_permitting suite: Thompson microphysics, scale-aware MYNN PBL + surface layer, RRTMG longwave/shortwave, Noah LSM, explicit convection (no cumulus parameterization), no sub-grid GWDO
Vertical	55 levels

What "3 km" means in this file

The output grid is a regular 0.03 ° lat-lon (~3 km N-S / ~2.55 km E-W at 40 °N). The underlying MPAS mesh varies from 3.05 km at the centre (40.63 °N, -74.09 °W) to 3.5-4.0 km at the corners of this box. The four target ASOS stations -- KBOS, KNYC, KPHL, KDCA -- are all within 321 km of the centre and sit on native 3-km cells.

Contents

forecasts/<YYYYMMDD>/NE_<YYYYMMDD>.nc — one netCDF per run, regridded from the native MPAS mesh with convert_mpas onto a regular 0.03 ° latitude-longitude grid covering 34-47 °N, 85-65 °W (434 × 668). Physical spacing is 3.33 km N-S and 2.55 km E-W at 40 °N. The output box was chosen empirically to bound the region where the underlying MPAS mesh is natively 3.0-4.0 km (measured 3.05 km at the centre, 3.5 km at 1000 km out). Every cell in the output file therefore lies over native fine-mesh data -- no oversampling of coarser MPAS cells.

• 2 m / surface diagnostics at 15-minute cadence — t2m, dewpoint, u10/v10, MSLP, precipitable water, accumulated precipitation, outgoing longwave radiation, CAPE.
• Three-dimensional / isobaric fields at hourly cadence — temperature, geopotential height, wind components and relative humidity on pressure levels.

The 15-minute surface cadence is deliberate: the daily temperature maximum at a coastal station can be set and then capped within minutes by a sea-breeze front, so hourly output aliases it.

Provenance & credits

• MPAS-Atmosphere — NCAR/LANL (mpas-dev.github.io).
• GFS initial conditions — NOAA/NCEP, via the AWS Open Data noaa-gfs-bdp-pds archive.
• Static geography — WPS_GEOG (NCAR).

Research output; provided as-is, with no warranty. Not an official forecast — for official forecasts and warnings see the NOAA National Weather Service (weather.gov).