:Product: 3-Day Forecast
:Issued: 2021 Sep 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 Sep 22-Sep 24 2021 is 4 (below NOAA
Scale levels).

NOAA Kp index breakdown Sep 22-Sep 24 2021

            Sep 22     Sep 23     Sep 24
00-03UT        3          3          3     
03-06UT        3          2          2     
06-09UT        2          2          2     
09-12UT        2          2          2     
12-15UT        1          4          2     
15-18UT        1          3          2     
18-21UT        2          3          2     
21-00UT        3          3          2     

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-16 over the past 24 hours, was
below S-scale storm level thresholds.

Solar Radiation Storm Forecast for Sep 22-Sep 24 2021

              Sep 22  Sep 23  Sep 24
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 Sep 22-Sep 24 2021

              Sep 22        Sep 23        Sep 24
R1-R2           10%           10%           10%
R3 or greater    1%            1%            1%

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