Objective:
- Understand topographic effects on low-level flow in eastern Wyoming
Model Setup:
- Three nested grids; deep model domain (>15km); finest grid centered on eastern Wyoming
- Dry runs only (no microphysics)
- Horizontally homogeneous initializations based on modifications of observed sounding
- Observed sounding: North Platte, Nebraska, 1200 UTC 26 June 1999:
Set A simulations:
- Finest possible topography on all grids
- Low-level vertical grid spacing = 100m
- No-radiation runs initialized with deep near-neutral surface layer
Set B simulations:
- Slightly smoothed topography on grids 2 and 3
- Low-level vertical grid spacing = 150m
- No-radiation runs initialized with more stable deep surface layer
Set A simulations - results on Grid 3:
- Case designated by initial uniform wind (degrees, m/s)
- Horizontal maps at lowest model level (~50m AGL)
A1) No-radiation, no-coriolis runs with uniform 3D flow:
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180/5 |
180/10 |
180/15 |
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150/5 |
150/10 |
150/15 |
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120/5 |
120/10 |
120/15 |
| Initial Sounding |
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| 0h Wind/Topo |
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| 2h Wind/Topo |
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| 2h Speed |
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| 2h Vert. Velocity |
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| 6h Wind/Topo |
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| 6h Speed |
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| 6h Vert. Velocity |
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| 6h Speed (yz plot) |
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| 6h Theta (xz plot) |
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A2) No-radiation runs with coriolis in uniform 3D flow;
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180/10cor |
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120/10cor |
| Initial Sounding |
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| 0h Wind/Topo |
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| 2h Wind/Topo |
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| 2h Speed |
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| 2h Vert. Velocity |
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| 6h Wind/Topo |
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| 6h Speed |
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| 6h Vert. Velocity |
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| 6h Speed (yz plot) |
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| 6h Theta (xz plot) |
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Set B simulations - results on Grid 3:
- Case designated by initial uniform or low-level wind
B1) No-radiation, no-coriolis runs in uniform 3D flow:
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180/10 |
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150/10 |
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120/10 |
| Initial Sounding |
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| 0h Wind/Topo |
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| 2h Wind/Topo |
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| 2h Speed |
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| 2h Vert. Velocity |
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| 6h Wind/Topo |
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| 6h Speed |
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| 6h Vert. Velocity |
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| 6h Speed (yz plot) |
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| 6h Theta (xz plot) |
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B2) No-radiation runs with coriolis in uniform 3D flow:
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180/10cor |
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150/10cor |
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120/10cor |
| 0h Wind/Topo |
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| 2h Wind/Topo |
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| 2h Speed |
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| 2h Vert. Velocity |
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| 6h Wind/Topo |
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| 6h Speed |
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| 6h Vert. Velocity |
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| 6h Speed (yz plot) |
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| 6h Theta (xz plot) |
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B3) No-radiation runs with coriolis and vertical shear in horizontally homogeneous flow:
- Uniform flow below 2500m MSL veers to 270/15 at 3500m MSL
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180/10sh |
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150/10sh |
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120/10sh |
| Initial Sounding |
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| 0h Wind/Topo |
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| 2h Wind/Topo |
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| 2h Speed |
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| 2h Vert. Velocity |
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| 6h Wind/Topo |
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| 6h Speed |
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| 6h Vert. Velocity |
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| 6h Speed (yz plot) |
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| 6h Theta (xz plot) |
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B4) Radiation runs with coriolis in uniform 3D flow:
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180/10rad |
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150/10rad |
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120/10rad |
| Initial Sounding |
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| 0h Wind/Topo |
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| 2h Wind/Topo |
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| 2h Speed |
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| 2h Vert. Velocity |
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| 6h Wind/Topo |
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| 6h Speed |
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| 6h Vert. Velocity |
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| 10h Wind/Topo |
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| 10h Speed |
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| 10h Vert. Velocity |
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| 6h Speed (yz plot) |
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| 6h Theta (xz plot) |
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| 10h Speed (yz plot) |
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| 10h Theta (xz plot) |
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B5) Radiation runs with coriolis and vertical shear in horizontally homogeneous flow:
- Uniform flow below 2500m MSL veers to 270/15 at 3500m MSL
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180/10shrad |
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150/10shrad |
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120/10shrad |
| Initial Sounding |
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| 0h Wind/Topo |
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| 2h Wind/Topo |
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| 2h Speed |
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| 2h Vert. Velocity |
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| 6h Wind/Topo |
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| 6h Speed |
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| 6h Vert. Velocity |
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| 10h Wind/Topo |
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| 10h Speed |
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| 10h Vert. Velocity |
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| 6h Speed (yz plot) |
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| 6h Theta (xz plot) |
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| 10h Speed (yz plot) |
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| 10h Theta (xz plot) |
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