3-Day Forecast

Issued: 2025 Apr 17 0030 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 8 (NOAA scale G4).

The greatest expected 3 hr Kp for Apr 17-Apr 19 2025 is 6 (.33NOAA scale G2).

NOAA Kp index breakdown

             Apr 17       Apr 18       Apr 19
00-03UT       6.33 (G2)    3.67         2.67     
03-06UT       5.67 (G2)    4.33         2.00     
06-09UT       5.33 (G1)    3.00         2.67     
09-12UT       4.33         3.00         2.33     
12-15UT       3.33         2.67         2.33     
15-18UT       3.33         3.00         2.33     
18-21UT       3.33         3.00         2.33     
21-00UT       3.33         3.00         2.33     

Rationale

G1-G2 (Minor-Moderate) geomagnetic storms are expected on 17 Apr due to CME influences.

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 Apr 17-Apr 19 2025

              Apr 17  Apr 18  Apr 19
S1 or greater    1%      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 Apr 17-Apr 19 2025

              Apr 17        Apr 18        Apr 19
R1-R2           60%           60%           60%
R3 or greater   10%           10%           10%

Rationale

R1-R2 (Minor-Moderate) or greater radio blackouts are likely on 17-19 Apr.