Holland Vortex • Coastal Hazard Dynamics

Offshore Hurricane Hazard Lab

Model offshore tropical cyclone tracks, asymmetric gale-to-hurricane wind radii, deep-water swell propagation, and coastal orographic rainfall—evaluating shore risks even when storms stay at sea.

Presets:

Storm Physics Parameters Cat 4 (115 kt)

Max Sustained Wind ($V_{max}$) 115 kt / 132 mph

Central Pressure ($P_c$) 944 hPa

Radius of Max Winds ($R_{max}$) 28 km

Holland B Parameter 1.45

Kinematics & Motion Vector

Translation Speed ($V_{trans}$) 11 kt (20 km/h)

Track Heading 305° (NW)

Offshore Distance to Nearest Shore 168 km

Atmospheric Environment

Ambient Precipitable Water 62 mm (High)

Tip: Drag the storm core directly on the map stage. Click coastal telemetry stations to inspect wave runup and rainfall orographic multipliers.

Eastern Pacific Cyclone System Cat 4

VORTEX TELEMETRY

Core Pos: 16.2°N, 103.5°W

Min Central Press: 944 hPa

64-kt Hurricane Radius: 78 km

34-kt Gale Radius: 242 km

64-kt Hurricane Force

50-kt Storm Force

34-kt Tropical Gale

Offshore Swell Rays

Orographic Elevation

Coastal Impact Monitoring Stations (Southwestern Shoreline)

Offshore simulation active. Drag vortex or adjust physics sliders.

Why Offshore Hurricanes Still Devastate Coastlines

When powerful tropical systems like Category 4 Hurricane Polo parallel coastlines 100 to 200 km offshore without direct eye landfall, public risk perception often drops dangerously. However, cyclonic physics dictates multiple non-landfall hazards:

Outer Rainbands & Topographic Lift: Cyclonic moisture convergence slamming into steep coastal ranges triggers extreme orographic enhancement, producing catastrophic inland flash flooding and landslides.
Long-Period Deep-Water Swells: High wind fetch inside the vortex generates 5 to 9 meter swells traveling hundreds of kilometers ahead, producing dangerous surf, structural coastal battering, and severe rip currents.
Right-Front Quadrant Asymmetry: In the Northern Hemisphere, forward motion adds 10–20 kt to the right-hand eyewall winds, extending gale-force conditions onto coastal headlands.

Physical Formulation & Computational Physics

This laboratory implements established meteorological models for operational diagnostic risk estimation:

Holland Radial Vortex Equation (1980): Computes wind speed as a function of radial distance: V(r) = sqrt( (B/ρ) * (Rmax/r)^B * ΔP * exp(-(Rmax/r)^B) + (r*f/2)^2 ) - (r*f/2)
Significant Wave Height ($H_s$): Empirical JONSWAP/SMB fetch-limited relationship factoring surface wind stress $U_{10}^2$ and radial duration.
Orographic Precipitation Multiplier: Calculated via cross-barrier moisture flux $w = \mathbf{V} \cdot \nabla h_{topo} \cdot q_{vapor}$.