600
FXXX10 KWNP 231231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Apr 23 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 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Apr 23-Apr 25 2026 is 3.00 (below NOAA
Scale levels).

NOAA Kp index breakdown Apr 23-Apr 25 2026

             Apr 23       Apr 24       Apr 25
00-03UT       2.33         2.33         2.33
03-06UT       3.00         2.67         2.67
06-09UT       2.33         2.67         2.33
09-12UT       2.00         1.67         2.00
12-15UT       0.67         1.33         1.33
15-18UT       2.00         2.00         1.67
18-21UT       2.67         2.00         2.00
21-00UT       3.00         2.33         2.67

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 Apr 23-Apr 25 2026

              Apr 23  Apr 24  Apr 25
S1 or greater   10%     10%     10%

Rationale: There is a slight chance for S1 (Minor) or greater solar
radiation storms through 25 Apr.

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 23 2026 0848 UTC.

Radio Blackout Forecast for Apr 23-Apr 25 2026

              Apr 23        Apr 24        Apr 25
R1-R2           55%           55%           55%
R3 or greater   20%           20%           20%

Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a
slight chance for R3 (Strong) or greater blackouts on 23-25
Apr-primarily due to the flare potential from Regions 4419 and 4420, as
well as activity from regions beyond the East limb.