:Product: 3-Day Forecast
:Issued: 2026 Apr 10 0030 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 2 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Apr 10-Apr 12 2026 is 5.33 (NOAA Scale
G1).

NOAA Kp index breakdown Apr 10-Apr 12 2026

             Apr 10       Apr 11       Apr 12
00-03UT       3.33         5.33 (G1)    4.33     
03-06UT       5.00 (G1)    4.00         3.67     
06-09UT       4.33         4.00         2.67     
09-12UT       3.67         3.33         2.33     
12-15UT       2.67         3.67         3.00     
15-18UT       2.67         4.00         2.33     
18-21UT       2.67         4.67 (G1)    3.00     
21-00UT       4.33         4.67 (G1)    3.33     

Rationale: G1 (Minor) storm levels are likely over 10-11 Apr due to the
influence of a +CH HSS.

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 10-Apr 12 2026

              Apr 10  Apr 11  Apr 12
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

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Apr 09 2026 0845 UTC.

Radio Blackout Forecast for Apr 10-Apr 12 2026

              Apr 10        Apr 11        Apr 12
R1-R2           25%            5%            5%
R3 or greater    1%            1%            1%

Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
on 10 Apr.