:Product: 3-Day Forecast

:Issued: 2021 Oct 25 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 2 (below NOAA

Scale levels).

The greatest expected 3 hr Kp for Oct 25-Oct 27 2021 is 3 (below NOAA

Scale levels).



NOAA Kp index breakdown Oct 25-Oct 27 2021



            Oct 25     Oct 26     Oct 27

00-03UT        1          2          2     

03-06UT        2          1          2     

06-09UT        1          1          3     

09-12UT        1          1          2     

12-15UT        1          1          1     

15-18UT        1          1          2     

18-21UT        2          2          2     

21-00UT        2          2          3     



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 Oct 25-Oct 27 2021



              Oct 25  Oct 26  Oct 27

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 Oct 25-Oct 27 2021



              Oct 25        Oct 26        Oct 27

R1-R2           10%           10%           10%

R3 or greater    1%            1%            1%



Rationale: There is a slight chance for isolated R1-R2 (Minor-Moderate)

radio blackouts over 25-27 Oct.