:Product: 3-Day Forecast
:Issued: 2018 May 21 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 1 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for May 21-May 23 2018 is 4 (below NOAA
Scale levels).

NOAA Kp index breakdown May 21-May 23 2018

            May 21     May 22     May 23
00-03UT        0          2          2     
03-06UT        1          2          2     
06-09UT        1          1          3     
09-12UT        1          1          4     
12-15UT        1          1          3     
15-18UT        1          1          3     
18-21UT        2          1          3     
21-00UT        2          2          3     

Rationale: No G1 (Minor) or greater geomagnetic storms are expected.  

B. NOAA Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-15 over the past 24 hours, was
below S-scale storm level thresholds.

Solar Radiation Storm Forecast for May 21-May 23 2018

              May 21  May 22  May 23
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 May 21-May 23 2018

              May 21        May 22        May 23
R1-R2            1%            1%            1%
R3 or greater    1%            1%            1%

Rationale: No R1 (Minor) or greater radio blackouts are expected.  No
significant active region flare activity is forecast.
.

Source: NOAA