:Product: 3-Day Forecast
:Issued: 2026 Aug 22 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 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Aug 22-Aug 24 2026 is 3.33 (below NOAA
Scale levels).

NOAA Kp index breakdown Aug 22-Aug 24 2026

             Aug 22       Aug 23       Aug 24
00-03UT       3.00         3.00         1.67     
03-06UT       3.33         2.00         1.33     
06-09UT       2.33         2.00         1.33     
09-12UT       2.33         2.00         1.33     
12-15UT       2.00         2.00         1.33     
15-18UT       1.00         2.00         1.33     
18-21UT       2.00         2.00         1.67     
21-00UT       2.00         2.33         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 Aug 22-Aug 24 2026

              Aug 22  Aug 23  Aug 24
S1 or greater    5%      5%      5%

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 Aug 21 2026 1018 UTC.

Radio Blackout Forecast for Aug 22-Aug 24 2026

              Aug 22        Aug 23        Aug 24
R1-R2           40%           40%           40%
R3 or greater   10%           10%           10%

Rationale: There is a chance for isolated R1-R2 (Minor-Moderate) radio
blackouts, and a slight chance for R3 (Strong) events on 22-24 Aug,
mostly due to the flare potential of Region 4513.