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Full catalog/RTMA
RTMA·dataset

Best-guess US surface weather map, hourly (NOAA)

NOAA Real-Time Mesoscale Analysis (RTMA) / Unrestricted Mesoscale Analysis (URMA)
atmosphere NOAA NOAA active
In plain English

What it measures. A high-resolution hourly snapshot of current near-surface weather across the U.S., blending observations into a complete gridded picture at 2.5 to 3 km.

How it's made. NOAA combines conventional and satellite observations using its statistical analysis system to produce the most accurate present-conditions grid possible.

How & where you'd use it. Forecasters use it for situational awareness and to check how their forecasts performed; a delayed version (URMA) refines the picture as more data arrives.

What's measured

aws-pdsagricultureclimatemeteorologicalweather

Coverage & cadence

  • Time span— → ongoing

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

The Real-Time Mesoscale Analysis (RTMA) is a NOAA National Centers For Environmental Prediction (NCEP) high-spatial and temporal resolution analysis/assimilation system for near-surf ace weather conditions. Its main component is the NCEP/EMC Gridpoint Statistical Interpolation (GSI) system applied in two-dimensional variational mode to assimilate conventional and satellite-derived observations. The RTMA was developed to support NDFD operations and provide field forecasters with high quality analyses for nowcasting, situational awareness, and forecast verification purposes. The system produces hourly analyses at 2. 5 km resolution for the Conus NDFD grid, 3 km for the Alaska NDFD grid and 2.5 km for the Hawaii, Puerto-Rico and Guam NDFD grids. Data is available from the start of 2019 until present. URMA is a time lagged version of this product and is updated when new observations come in.

Get the data

noaa_access.py
# NOAA Open Data on AWS — public S3, no login
import s3fs

fs = s3fs.S3FileSystem(anon=True)
# find this dataset's bucket in the docs link in the sidebar, then:
# files = fs.ls("noaa-<bucket>/...")
# open NetCDF/GRIB with xarray, COGs with rioxarray
NOAA Open Data is on public AWS S3 — no login at all (anonymous access).