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Service Change Notice 25-23
National Weather Service Headquarters Silver Spring MD
1015 AM EST Thu Feb 27 2025

To: Subscribers:
 -NOAA Weather Wire Service
 -Emergency Managers Weather Information Network
 -NOAAPort
 Other NWS Partners, Users and Employees

From: Bruce Entwistle, Chief
 Aviation and Space Weather Services Branch

Subject: Operational Implementation of Updated Solar Cycle 25
Prediction Product: Effective March 31, 2025

Effective on or about March 31, 2025, at 1700 Coordinated
Universal Time (UTC), the National Weather Service will
operationally implement an updated version of the prediction for
Solar Cycle 25. The new product is currently available as an
experimental product here:

https://testbed.swpc.noaa.gov/products/solar-cycle-progression-
interactive

This updated prediction is an enhancement of the solar cycle
progression products now distributed on the following public
webpages:

https://www.swpc.noaa.gov/products/solar-cycle-progression

https://www.swpc.noaa.gov/products/predicted-sunspot-number-and-
radio-flux

https://services.swpc.noaa.gov/json/solar-cycle/predicted-solar-
cycle.json

The existing products include a prediction for Solar Cycle 25
from an international panel composed of experts from National
Oceanic and Atmospheric Administration/National Aeronautics and
Space Administration/International Space Environment Services
that convened in 2019 and presented their findings at the 2019
Annual Space Weather Workshop.

The new product leverages the latest observations of the
international sunspot number and the 10.7 cm radio flux to
provide more accurate predictions of solar activity progression
through the year 2030.

This new version provides the following products, each of which
will be updated on a monthly basis (on or about the 2nd day of
the month) as new observations become available:

1. A graphical figure showing the observed monthly sunspot
  number for Solar Cycle 25, which began in 2019, and the
  predicted sunspot number through 2032. Uncertainty in the
  prediction is portrayed as quartiles.
2. Similar to item 1 but showing observations and predictions
  for the F10.7 cm radio flux through 2032.
3. A file in JSON (JavaScript Object Notation) format containing
  quantitative values for the predicted sunspot number and
  F10.7 cm radio flux through 2032, with estimated
  uncertainties.

Effective on or about March 31, 2025, these new experimental
products will replace the current Solar Cycle and F10.7 cm radio
flux predictions on the Space Weather Prediction Center (SWPC)
website.

A Product Description Document for the Operational Deployment of
Updated Solar Cycle Prediction Product is provided online:

https://nsdesk.servicenowservices.com/api/g_noa/nwspc/res2/c91e8
a56973bd6508881bb7de053afbe

For any additional comments/feedback on this change at SWPC,
please contact:

Mark Miesch
CIRES/University of Colorado
NOAA Space Weather Prediction Center
Boulder, CO
Email: mark.miesch@noaa.gov

and

Dr. Jennifer Meehan
National Space Weather Program Manager
National Weather Service Headquarters
Silver Spring, MD
Email: jennifer.meehan@noaa.gov

National Service Change Notices are online at:

https://www.weather.gov/notification