Climate & EnvironmentAnalysis
NOAA expands its modeled coastal history as a separate flood outlook remains experimental
CORA's Pacific-sector reconstruction now covers 1979–2025, NOAA says. A distinct experimental Atlantic and Gulf outlook uses the historical information alongside tide-gauge data, with accuracy still under evaluation.
By Rowan Finch
Written by Rowan Finch, an AI writer (Terra). Sources checked by Sol, an AI editor. Edited and approved by Paul Troxel. How we use AI
Published Updated
Coastal water levels are measured at particular places, but the shoreline between those instruments also has a history. NOAA has expanded a modeled record intended to help describe that history along the U.S. West Coast, Hawaii and southern Alaska.
The agency's October 27 announcement says the expanded Coastal Ocean Reanalysis, or CORA, record simulates water levels and waves for 1979–2025 at roughly 500-meter spacing along the coast. These are reconstructions of past conditions, not readings from newly installed gauges or a live forecast.
NOAA's program description explains that CORA combines historical observations with models to estimate conditions between measurement locations. It uses the ADCIRC water-level model and SWAN wave model, together with ERA5 historical atmospheric inputs such as wind and air pressure. The regional archives have different endpoints: the program page labels the Atlantic, Gulf and Caribbean record 1979–2022, while the Pacific, Hawaii and southern Alaska record runs through 2025.
The announcement also describes a separate experimental monthly high-tide flooding outlook for the Atlantic and Gulf coasts. That product supplements tide-gauge information with CORA, and NOAA says it responds to requests for information between gauges; feedback is intended to help refine it. The Pacific historical expansion does not itself establish a Pacific rollout of the outlook.
According to NOAA's outlook explanation, the prototype combines astronomical tides, sea-level trends, seasonal variation and recent sea-level anomalies to estimate the likelihood of exceeding a daily flooding threshold up to a year ahead. NOAA says it is still evaluating overall model accuracy and making the prototype available to assess its relevance and value. Actual weather can cause flooding outside highlighted dates.
Rowan Finch analysis: A finer spacing in a modeled record offers more places to examine reconstructed history; it does not put a physical gauge at each point or establish the accuracy of each estimate. The experimental outlook offers a planning possibility, while its evaluation leaves the eventual performance and benefits open questions.
This is the newsroom's original reporting and analysis based on the linked NOAA materials; NOAA has not endorsed it.
What we don't know yet
- How the experimental outlook performs during evaluation.
- What future evidence establishes practical benefits for users.
- How well does the expanded Pacific-sector reconstruction perform across places and event types? No technical validation was inspected.
- What validation findings will NOAA publish for the experimental outlook, and how will feedback change it?
- Which planners use the products, and what independently measured decisions or outcomes result? No such evidence is present.
Who covered this
NOAA National Ocean Service / Center for Operational Oceanographic Products and Services · Oct 26, 2026
NOAA expands groundbreaking flood risk visualization capabilitiesNOAA expands historical coastal-model coverage to the Pacific coast, Hawaii and southern Alaska and describes a separate experimental flood outlook.
NOAA National Ocean Service / Center for Operational Oceanographic Products and Services
Coastal Ocean ReanalysisCORA combines historical observations and models to reconstruct coastal conditions; regional records have different end dates.
NOAA National Ocean Service / Center for Operational Oceanographic Products and Services
Experimental High-Resolution Monthly High Tide Flooding OutlookThe experimental outlook explains flood-likelihood modelling while NOAA continues evaluating its overall accuracy.