412
FXXX10 KWNP 171231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Jun 17 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 2 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Jun 17-Jun 19 2025 is 4.33 (below NOAA
Scale levels).

NOAA Kp index breakdown Jun 17-Jun 19 2025

             Jun 17       Jun 18       Jun 19
00-03UT       2.00         3.33         3.67
03-06UT       2.00         3.00         3.33
06-09UT       2.33         2.00         2.00
09-12UT       2.67         2.33         3.00
12-15UT       2.33         2.67         1.67
15-18UT       1.67         3.33         1.67
18-21UT       3.00         4.00         2.67
21-00UT       3.33         4.33         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 Jun 17-Jun 19 2025

              Jun 17  Jun 18  Jun 19
S1 or greater   25%     15%     10%

Rationale: There is a chance for S1 (Minor) solar radiation event on 17
June, mainly due to activity associated with Region 4114, before
probabilities gradually lessen on 18-19 June.

C. NOAA Radio Blackout Activity and Forecast

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Jun 16 2025 1455 UTC.

Radio Blackout Forecast for Jun 17-Jun 19 2025

              Jun 17        Jun 18        Jun 19
R1-R2           75%           75%           75%
R3 or greater   25%           25%           25%

Rationale: R1-R2 (Minor-Moderate) flaring is expected with a chance for
X-class flares (R3-Strong) on 17-19 Jun, mostly driven by Regions 4114
and 4115.