An official website of the United States government. Here's how you know. ⇵

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Latest DESI upgrade includes next-generation model data

A high-resolution weather visualization map titled “RRFS Wind Speeds over North America,” issued by NOAA’s Global Systems Laboratory on Friday, May 23, 2025, at 1 pm MDT. The map shows wind speeds across the continent using a color scale from 0 to 100+ mph, with light blues indicating lower speeds and yellows-to-purples marking higher speeds. Distinct swirling wind patterns (cyclonic systems) appear over the North Pacific Ocean near Alaska and off the East Coast near Greenland. Major cities like Seattle, Los Angeles, Denver, Houston, Charlotte, and New York City are marked for reference. The RRFS (Rapid Refresh Forecast System) domain spans North America and surrounding oceans, supporting detailed high-resolution weather prediction.
DESI display of RRFS forecast wind speeds over North America. RRFS’s North America domain allows for high-resolution weather prediction across the entire continent and surrounding oceans. Image credit: NOAA GSL.

GSL has released its latest update to the powerful Dynamic Ensemble Scenarios for Impact-Based Decision Support (DESI) tool on both the GSL experimental product development server and the National Weather Service (NWS) cloud platform. This milestone occurs as NWS continues to expand its use of DESI at its Weather Forecast Offices to develop weather forecasts and produce hazardous weather briefings for partners and the public.

This release (Version 3.4, completed in May 2025) marks the first time that data from the experimental Rapid Refresh Forecast System (RRFS) and Rapid Ensemble Forecast System (REFS) are accessible in DESI. RRFS, the next-generation, rapidly-updating, high-resolution forecast system under development by GSL and partners for several years, runs hourly and produces high-resolution forecasts over all of North America. It is NOAA’s first convection-allowing model to cover the entire continent and its island territories. REFS, the ensemble version of RRFS, covers the continental U.S, Alaska, Hawaii, and Puerto Rico and runs every six hours.

With these systems being integrated into DESI, users now also have access to new RRFS forecast fields, including Hourly Wildfire Potential and surface and vertically-integrated smoke and dust forecasts. Currently, the RRFS and REFS products are available on DESI’s experimental GSL platform.

A weather visualization map titled “Canadian Wildfire Smoke (RRFS),” produced by NOAA’s Global Systems Laboratory and issued Wednesday, May 28, 2025, at 5 pm MDT, showing a forecast for Thursday, May 29, 2025, at 8 am MDT. The map displays RRFS-modeled vertically integrated smoke concentrations (in mg/m²) from wildfires in central Canada. Dense smoke plumes (deep orange and brown) are concentrated over Manitoba and Ontario, with a wide smoke band stretching eastward across Quebec, the Gulf of St. Lawrence, and Newfoundland, and drifting southward toward the U.S. Midwest and Northeast. Major cities like Denver, Omaha, Minneapolis, Chicago, and New York City are marked on the map. The DESI 3.4 system enables visualizations of RRFS-Smoke predictions across North America.
RRFS-modeled vertically-integrated smoke emitted by wildfires in Central Canada in May 2025. DESI 3.4 allows for visualizations of RRFS-Smoke predictions across all of North America. Image credit: NOAA GSL

DESI is designed to allow forecasters to explore large amounts of weather data and generate forecasts as quickly and efficiently as possible. The new additions in DESI 3.4 provide users with even more opportunities to evaluate and interrogate data, honing in on specific risks or other forecast criteria. This release also includes performance upgrades, allowing, in some cases, for probabilistic forecasts and timing calculations to complete over 8 times faster than in the previous releases.

These upgrades come as DESI reaches several major milestones, including being leveraged by NWS during the 2025 operational field evaluation of RRFS Version 1.0 and the evaluation of experimental hurricane forecasting tools in the Hurricane and Ocean Testbed.

As GSL and NWS work toward a transition plan to integrate DESI into full, nationwide operations, stay tuned to GSL for future news about further upgrades and new functionality.

A weather probability map titled “REFS 24-Hour Probability of >0.10” of Rain,” produced by NOAA’s Global Systems Laboratory and issued Friday, May 23, 2025, at 10 am MDT, showing a forecast for Saturday, May 24, 2025, at 12 pm MDT. The map displays the REFS model’s probabilistic forecast for rainfall over Puerto Rico and surrounding areas, using a color scale from 5% to 100% chance. Bright oranges and yellows highlight areas with the highest probability (>70%) of receiving more than 0.10 inches of rain, especially concentrated over western Puerto Rico and the Mona Passage. Purples and blues mark lower probabilities spreading outward across the surrounding Caribbean. The DESI 3.4 system enables visualization of ensemble-based probabilistic forecasts over an expanded domain, including Puerto Rico.
DESI display showing the REFS probability of greater than 0.10” of rain in a 24-hour period over Puerto Rico. DESI 3.4 allows for visualization of probabilistic, ensemble predictions over an expanded domain, including Puerto Rico. Image credit: NOAA GSL.
Last Update: June 03, 2025

Our Mission

Lead research and directed development through the transition of environmental data, models, products, tools, and services to support commerce, protect life and property, and promote a scientifically literate public.

Research Areas

Organizational Excellence, Earth System Prediction, Advanced Technologies, and Decision Support are the foundation to achieving the GSL Grand Challenge: Deliver actionable global storm-scale prediction and environmental information through advanced technologies to serve society.

Global Systems Laboratory