Tidal Surge Patterns and Surf Forecasts: Unlocking the Power of Integrated Modeling

As surfers, beachgoers, and coastal residents alike, we've all witnessed the dramatic power of tidal surges. These sudden and unpredictable ocean events can bring with them waves of up to 10 feet in just a matter of minutes, inundating shorelines and causing widespread damage. However, predicting these tidal surges and surf conditions requires an intricate understanding of various weather phenomena, including numerical weather prediction (NWP) models.

In this blog post, we'll explore the fascinating intersection of NWP integration with ocean currents, heat fluxes, and tidal patterns to provide a more comprehensive understanding of surf forecasting.

Scenario: A Tidal Surge Off the Coast of California

Let's consider an example scenario where a large tidal surge is predicted to affect the coast of Northern California. The National Weather Service (NWS) issues a Surf Forecast Advisory for the following areas:

• Santa Cruz, Monterey, and Big Sur
• The San Francisco Bay Area

The NWS model predicts that the surge will occur around 9 PM PST on Wednesday evening, with wave heights reaching up to 10 feet in some areas. However, as we dive deeper into the forecast, we notice a complex interplay of factors influencing the tidal surge.

Numerical Weather Prediction (NWP) Model Integration

The NWS uses its proprietary model, which combines data from various sources, including:

1. Reanalysis Data: The NWS utilizes high-resolution reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF), providing a more accurate representation of atmospheric conditions.
2. Upper Air Observations: The National Weather Service collects data from automated weather stations and radar systems, offering insights into atmospheric pressure, temperature, and humidity patterns.
3. Model Output Statistics (MODS): The NWS uses MODS, which provide detailed information on the model's performance, including forecast errors and biases.

By integrating these data sources, the NWS model produces a high-resolution forecast of tidal surge characteristics, including wave height, period, and direction.

Ocean Currents and Heat Fluxes

As we analyze the model output, we notice that ocean currents play a significant role in shaping the tidal surge pattern. The California Current, which flows northward along the coast, helps drive the formation of strong tidal waves during this time. Additionally, heat fluxes from the warm waters of the Pacific Ocean influence wave growth and period.

Tidal Surge Characteristics

Using the integrated model output, we can now forecast the characteristics of the tidal surge:

• Wave Height: Up to 10 feet in some areas, with a maximum wave period of around 20 seconds.
• Direction: WNW (west-northwest) to ESE (east-southeast), resulting in waves that approach shore at an angle.
• Duration: Approximately 30 minutes to 1 hour, with the surge reaching its peak during the late afternoon.

Tidal Surge Prediction and Surf Forecasting

By combining NWP model output with ocean currents and heat fluxes, surf forecasters can create more accurate predictions of tidal surge patterns. This integrated approach allows for a better understanding of the complex interactions between atmospheric conditions, oceanic factors, and surface roughness.

In practice, this means:

• Better Wave Predictions: Surf forecasters can now accurately predict wave heights, periods, and directions, enabling them to provide more accurate warnings and advisories for beachgoers.
• More Efficient Resource Allocation: By understanding the underlying drivers of tidal surge patterns, surf forecasters can allocate resources more effectively, focusing on areas with higher risk.

Conclusion

The integration of NWP models with ocean currents, heat fluxes, and tidal patterns is a powerful tool in predicting tidal surges. By leveraging this advanced modeling approach, surf forecasters can provide more accurate and effective warnings for beachgoers, reducing the risk of damage and injury.

As we continue to explore the intersection of weather forecasting and oceanography, it's clear that the future of surf forecasting holds much promise. By embracing integrated modeling, we can unlock new insights into the complex dynamics driving our coastal regions – and ultimately, improve the safety of those who rely on the sea. Tidal Surge Patterns and Surf Forecasts: Unlocking the Power of Integrated Modeling

Scenario: A Tidal Surge Off the Coast of California

• NWS Model Output: High-resolution forecast from National Weather Service
  • Wave Height: Up to 10 feet in some areas
  • Wave Period: Approximately 20 seconds
  • Direction: WNW (west-northwest) to ESE (east-southeast)
• Ocean Currents and Heat Fluxes: Strong California Current, heat fluxes from warm Pacific Ocean

Tidal Surge Characteristics

Surf Forecasting and Resource Allocation

• Better Wave Predictions: Accurate predictions of wave heights, periods, and directions
• More Efficient Resource Allocation: Focus on areas with higher risk

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