3-Day Forecast

Issued: 2025 Dec 13 1230 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center and processed by SpaceWeatherLive.com

A. NOAA Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 5 (NOAA scale G1).

The greatest expected 3 hr Kp for Dec 13-Dec 15 2025 is 4 (.67NOAA scale G1).

NOAA Kp index breakdown

             Dec 13       Dec 14       Dec 15
00-03UT       4.67 (G1)    2.67         2.67     
03-06UT       2.00         3.67         2.67     
06-09UT       2.33         3.00         3.00     
09-12UT       2.33         2.67         2.67     
12-15UT       3.67         2.67         1.67     
15-18UT       2.67         2.00         1.67     
18-21UT       1.67         1.67         2.00     
21-00UT       2.67         2.67         2.67     

Rationale

No G1 (Minor) or greater geomagnetic storms are expected throughout the remainder of 13-15 Dec.

B. NOAA Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was below S-scale storm level thresholds.

Solar Radiation Storm Forecast for Dec 13-Dec 15 2025

              Dec 13  Dec 14  Dec 15
S1 or greater    5%      1%      1%

Rationale

No S1 (Minor) or greater solar radiation storms are expected. No significant active region activity favorable for radiation storm production is forecast.

C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Dec 13-Dec 15 2025

              Dec 13        Dec 14        Dec 15
R1-R2           45%           35%           25%
R3 or greater    5%            1%            1%

Rationale

There is a decreasing chance for R1-R2 (Minor-Moderate) radio blackouts over 13-15 Dec.