608
FXXX10 KWNP 181231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Apr 18 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 4 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Apr 18-Apr 20 2025 is 4.00 (below NOAA
Scale levels).

NOAA Kp index breakdown Apr 18-Apr 20 2025

             Apr 18       Apr 19       Apr 20
00-03UT       3.33         2.67         2.33
03-06UT       4.00         2.00         3.00
06-09UT       3.00         2.67         2.33
09-12UT       2.00         2.33         1.67
12-15UT       2.33         2.33         1.33
15-18UT       1.67         2.33         1.00
18-21UT       1.67         2.33         1.67
21-00UT       2.33         2.33         2.00

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 18-Apr 20 2025

              Apr 18  Apr 19  Apr 20
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 Apr 18-Apr 20 2025

              Apr 18        Apr 19        Apr 20
R1-R2           40%           40%           40%
R3 or greater    5%            5%            5%

Rationale: There is a chance for isolated R1-R2 (Minor-Moderate) radio
blackouts through 20 Apr.