- 4.8.0WRF-ARW version
- 3 kmFinest nest
- 72 hForecast length
- 18ZDaily GFS cycle
An operational WRF-ARW configuration run in house each day and co-located with the Lekwena radar and the NWU station network for verification. Model documentation is maintained by the WRF user community.
Synoptic overview
Surface analysis with the two upper-air levels that drive it, on the Southern Africa domain. Stepped three-hourly from T+12 h to T+72 h.
Official warnings
Issued by the South African Weather Service.
Impact dashboards
Model output scored per location against storm, heat, frost, fire and agricultural decision thresholds.
-
9 km domain
National Impact Dashboard
Thirty-two cities scored for convection, rainfall, wind, heat stress (Heat Index and WBGT), livestock heat load (THI, by species), frost, fire danger, spray windows and irrigation scheduling.
Open dashboard ↗ -
3 km domain
NWU Campus Dashboard
Convection-permitting guidance for the Potchefstroom, Mahikeng and Vanderbijlpark (Vaal) campuses.
Open dashboard ↗
Gridded fields
Each field is published at both resolutions. The 3 km nest resolves convection explicitly and is the better guide to thunderstorm timing, placement and mode over the Highveld.
Vertical profiles for 48 locations are on the soundings page.
Model domains
| Domain | Resolution | Grid | Extent | Coverage |
|---|---|---|---|---|
| d01 Outer domain |
18 km | 279 x 219 | 0.4-49.6E, 5.4-40.3S | Southern Africa Lateral boundary forcing only - not published as gridded fields |
| d02 Regional domain |
9 km | 214 x 200 | 15.9-34.8E, 21.2-36.5S | South Africa, Lesotho and Eswatini Cumulus parameterised |
| d03 Convection-permitting nest |
3 km | 246 x 156 | 22.0-29.2E, 24.1-28.2S | North West and Gauteng Cumulus scheme off - convection resolved explicitly |
The domains are two-way nested. The outer domain supplies lateral boundary conditions only; its gridded fields are not published.
Configuration
| Dynamical core | WRF-ARW v4.8.0, non-hydrostatic |
|---|---|
| Microphysics | Thompson (mp_physics = 6) |
| Cumulus | Kain-Fritsch on d01/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 |
| Cycle | Daily, from the 18Z GFS cycle |