clouds
Climatic Context for the December 2025 Stehekin Debris Flow Event
Overview
In December 2025, heavy rainfall on recently burned areas caused debris flows in the North Cascades, near Stehekin, Washington. This notebook offers climate context for the event using publicly available precipitation and streamflow data from NOAA and USGS APIs.
The goal is to assess whether December 2025 saw unusually high precipitation and river discharge that may have led to slope failure and debris flows.
Data Sources
1. USGS Water Services API
- Purpose: Real-time river discharge (streamflow) data
- Site: 12451000 (Stehekin River at Stehekin, WA)
- Parameter: 00060 (Discharge in cubic feet per second)
- Time Period: December 1-31, 2025
- Endpoint:
https://waterservices.usgs.gov/nwis/iv/ - Documentation: Link
2. NOAA Climate Data Online (CDO) API
- Purpose: Daily precipitation measurements
- Station: GHCND:USC00458059 (Stehekin 4 NW, WA US)
- Data Type: PRCP (Daily precipitation)
- Time Period: December 1-31, 2025
- Endpoint:
https://www.ncei.noaa.gov/cdo-web/api/v2/data - Documentation: Link
- Authentication: Requires API token (request at Link)
Results and Interpretation
Daily precipitation data indicate several storm events in December 2025, with rainfall increasing in early and mid-December. The most significant storm happened on December 17, recording the highest daily total of about 70 mm. This peak followed multiple days of heavy rainfall, suggesting the soil was already saturated.
Figure 1: USGS gage height (stage) for the Stehekin River showing long-term water level variability.
USGS stream gauge data from the Stehekin River indicate a significant hydrologic response to these storm
events. During mid-December, river stage and discharge quickly rose, with peak discharge surpassing 20,000 cfs.
Figure 2: Daily precipitation at NOAA GHCND station USC00458059 (Stehekin) for December 2025.
Figure 3: USGS streamflow for the Stehekin River showing discharge response during December 2025
storms.
The heavy rainfall and rapid river rise in December 2025 indicate a significant storm event. The recent burn area increased debris-flow risk by increasing runoff and destabilizing slopes.
Workflow Steps
AI Usage Statement
We used ChatGPT and Claude AI to assist with troubleshooting API data access, specifically for working
with USGS .rdb file formats, debugging Python code for data ingestion, and resolving plotting issues.
AI tools were also used to help identify data structure, interpret column formats, and debug
visualization errors. All analysis, interpretation, and final figures were completed by the team.
Climatic Context for the December 2025 Stehekin Debris Flow Event
Overview
In December 2025, heavy rainfall on recently burned areas caused debris flows in the North Cascades, near Stehekin, Washington. This document offers climate context for the event using publicly available precipitation and streamflow data from NOAA and USGS APIs. The goal is to assess whether December 2025 saw unusually high precipitation and river discharge that may have led to slope failure and debris flows.
Results and Interpretation
Daily precipitation data indicate several storm events in December 2025, with rainfall increasing in early and mid-December. The most significant storm happened on December 17, recording the highest daily total of about 70 mm. This peak followed multiple days of heavy rainfall, suggesting the soil was already saturated.
Figure 1:
USGS stream gauge data from the Stehekin River indicate a significant hydrologic response to these storm events. During mid-December, river stage and discharge quickly rose, with peak discharge surpassing 20,000 cfs.
Figure 2:
Figure 3:
The heavy rainfall and rapid river rise in December 2025 indicate a significant storm event. The recent burn area increased debris-flow risk by increasing runoff and destabilizing slopes.
Reproducibility
All precipitation and streamflow data were collected programmatically using public APIs (NOAA CDO and USGS
Water Services) and processed using Python with help from ChatGPT (see API_clouds_assignment file).