:Product: 3-Day Forecast
:Issued: 2026 Oct 15 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
A. NOAA Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Oct 15-Oct 17 2026 is 2.67 (below NOAA
Scale levels).

NOAA Kp index breakdown Oct 15-Oct 17 2026

             Oct 15       Oct 16       Oct 17
00-03UT       2.00         2.33         1.67         
03-06UT       0.67         2.67         1.67         
06-09UT       1.33         2.00         1.33         
09-12UT       2.33         1.67         1.33         
12-15UT       1.67         1.67         1.33         
15-18UT       1.00         2.00         1.33         
18-21UT       1.33         2.00         1.33         
21-00UT       2.33         2.67         1.67         

Rationale: No G1 (Minor) or greater geomagnetic storms are expected. No
significant transient or recurrent solar wind features are forecast.

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 Oct 15-Oct 17 2026

              Oct 15  Oct 16  Oct 17
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 Oct 15-Oct 17 2026

              Oct 15        Oct 16        Oct 17
R1-R2           20%           20%           20%
R3 or greater    5%            5%            5%

Rationale: No R1 (Minor) or greater radio blackouts are expected. No
significant active region flare activity is forecast.
