457
FXXX10 KWNP 131231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Aug 13 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 Aug 13-Aug 15 2025 is 3.67 (below NOAA
Scale levels).

NOAA Kp index breakdown Aug 13-Aug 15 2025

             Aug 13       Aug 14       Aug 15
00-03UT       2.67         2.67         2.67
03-06UT       3.00         3.67         3.67
06-09UT       2.67         2.33         2.33
09-12UT       3.00         2.00         2.00
12-15UT       2.67         2.00         2.00
15-18UT       2.00         2.00         2.00
18-21UT       2.00         2.33         2.33
21-00UT       3.67         2.33         2.33

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 Aug 13-Aug 15 2025

              Aug 13  Aug 14  Aug 15
S1 or greater    5%      5%      5%

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 Aug 13-Aug 15 2025

              Aug 13        Aug 14        Aug 15
R1-R2           50%           50%           45%
R3 or greater   10%           10%            5%

Rationale: A high chance for R1-R2 (Minor-Moderate) radio blackouts due
to M-class flare activity, most likely from Regions 4178 and/or 4172,
will persist through 15 August. Probabilities will begin to
decrease slightly on 15 August as Region 4178 exits the visible solar
disk.