599
FXXX10 KWNP 221231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Apr 22 1230 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# http://www.swpc.noaa.gov/wwire.html
#
#             3-Day Forecast
#
A. NOAA Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 5 (NOAA Scale
G1).
The greatest expected 3 hr Kp for Apr 22-Apr 24 2025 is 5.67 (NOAA Scale
G2).

NOAA Kp index breakdown Apr 22-Apr 24 2025

             Apr 22       Apr 23       Apr 24
00-03UT       3.67         4.00         4.00
03-06UT       3.00         4.67 (G1)    3.33
06-09UT       3.00         3.33         3.33
09-12UT       1.67         3.67         4.00
12-15UT       3.67         3.00         3.00
15-18UT       2.67         2.33         3.00
18-21UT       3.00         2.33         2.33
21-00UT       5.67 (G2)    3.67         2.67

Rationale: G1-G2 (Minor-Moderate) geomagnetic storms are likely on 22-23
Apr due to recurrent CH HSS influences.

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 22-Apr 24 2025

              Apr 22  Apr 23  Apr 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

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Apr 21 2025 1837 UTC.

Radio Blackout Forecast for Apr 22-Apr 24 2025

              Apr 22        Apr 23        Apr 24
R1-R2           40%           40%           40%
R3 or greater    1%            1%            1%

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