Official warnings
Weather overview
Impact dashboards
Agri forecast
Maize Trust Early Warning for Farmers project.
Forecast maps
Zoom in and play through the next three days, for all of South Africa or a closer look at North West and Gauteng.
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Rain & stormsSimulated radar
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Rainfall totalAccumulated precipitation
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Temperature2 m air temperature
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Wind gustsMax gust, Beaufort scale
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Feels-like temperatureUTCI
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Cloud coverCloud fraction
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HailHAILCAST max diameter
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Storm energyCAPE
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EvaporationAccumulated evapotranspiration
Want the atmosphere above a town? See the soundings.
About the forecast model
An in-house WRF-ARW 4.8.0 configuration, run twice a day from the 00Z and 12Z NCEP GFS cycles, 72 h ahead. It is a research forecast: only the SA Weather Service issues official warnings. Model documentation is kept by the WRF user community; custom forecasts on request from Dr Henno Havenga.
Domains
| Domain | Resolution | Grid | Extent | Coverage |
|---|---|---|---|---|
| d02 Outer domain |
9 km | 214 x 200 | 14.7-36.1E, 20.5-36.9S | South Africa, Lesotho and Eswatini Forced directly from GFS at the lateral boundary; cumulus parameterised |
| d03 Convection-permitting nest |
3 km | 246 x 156 | 21.9-29.4E, 23.6-27.9S | North West and Gauteng Cumulus scheme off - convection resolved explicitly |
Configuration
| Dynamical core | WRF-ARW v4.8.0, non-hydrostatic |
|---|---|
| Map projection | Lambert Conformal (true latitudes -23.7 and -34.0) |
| Microphysics | Thompson (mp_physics = 6) |
| Cumulus | Kain-Fritsch on d02, off on d03 |
| Longwave radiation | RRTMG (ra_lw_physics = 3) |
| Shortwave radiation | RRTMG (ra_sw_physics = 3) |
| Planetary boundary layer | YSU (bl_pbl_physics = 1) |
| Surface layer | Revised MM5 Monin-Obukhov (sf_sfclay_physics = 1) |
| Land surface | Unified Noah LSM (sf_surface_physics = 2), 4 soil layers |
| Initial and boundary conditions | NCEP GFS 0.25 deg, 3-hourly |
| Forecast length | 72 h |
| Cycles | Twice daily, from the 00Z and 12Z GFS cycles |
Good to know
- Initialised from public GFS analyses, so GFS starting errors carry into the forecast.
- Discard the first hour of each run for spin-up.
- Verify against observed profiles in the University of Wyoming upper-air database.
Full forecast portal ↗ · Plain images without the zoomable map: forecast fields, SCEP, SAWS warnings list.