Land Interaction & Topography Effects

Overview

This pillar analyzes the critical interaction between a storm system and land topography. It quantifies how features like mountains, coastlines, and surface friction disrupt a storm's energy, providing a predictive edge for its intensity after landfall.

What It Does

The model simulates a storm's journey over land by integrating its projected path with high-resolution topographical data. It calculates the loss of energy from two key factors: the cutoff from warm ocean water and the increased surface drag from terrain. This produces a decay curve that predicts how quickly a storm will weaken.

Why It Matters

A storm's behavior over open water is well-understood, but its interaction with land is complex and highly variable. This pillar provides a crucial advantage by focusing on this landfall phase, allowing for more accurate predictions of a storm's eventual dissipation and impact inland.

How It Works

First, the pillar ingests official storm track and intensity forecasts. Second, it overlays this path onto a digital elevation and land cover map. Third, it calculates friction coefficients and orographic lift effects for each segment of the path over land. Finally, it outputs a projected intensity decay score, forecasting the storm's strength at various points inland.

Methodology

A Land Interaction Index (LII) is calculated by integrating terrain slope vectors and surface friction coefficients along a storm's projected 12-hour path post-landfall. The model applies an exponential decay function based on the LII and the storm's initial Saffir-Simpson category, adjusted for the 'island effect' where short land crossings cause less disruption.

Edge & Advantage

This provides a specific edge in predicting the *rate* of a storm's weakening, a variable often generalized in standard weather models, which is key for inland wind speed and damage markets.

Key Indicators

• Terrain Slope Vectors

  high

  Measures the steepness of terrain, which can disrupt a storm's circulation.

• Surface Friction Coefficients

  high

  Quantifies the drag caused by different land types (e.g., forests, cities) that slows a storm down.

• Island Effect Decay Rates

  medium

  Models the reduced impact of very short land crossings, such as over a small island or narrow peninsula.

Data Sources

• NOAA National Hurricane Center (NHC)

  Provides official forecasts for storm tracks, intensity, and wind speed probabilities.

• USGS Digital Elevation Models (DEM)

  High-resolution topographical data for analyzing terrain features.

• Global Land Cover Characterization (GLCC)

  Database used to determine surface roughness and friction coefficients for different land types.

Example Questions This Pillar Answers

• → Will Hurricane Zeta maintain hurricane strength 12 hours after making landfall?
• → What will be the peak wind speed in an inland city if a hurricane tracks directly over it?
• → Will this tropical storm weaken to a tropical depression within 24 hours of moving over the Appalachian Mountains?

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