952
FXXX10 KWNP 170031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Oct 17 0030 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 Oct 17-Oct 19 2025 is 5.00 (NOAA Scale
G1).

NOAA Kp index breakdown Oct 17-Oct 19 2025

             Oct 17       Oct 18       Oct 19
00-03UT       5.00 (G1)    3.00         4.00
03-06UT       4.67 (G1)    2.33         3.00
06-09UT       3.67         2.00         2.67
09-12UT       3.67         2.00         2.33
12-15UT       3.67         2.00         2.00
15-18UT       3.33         4.00         2.00
18-21UT       3.00         4.00         2.00
21-00UT       2.67         4.33         2.33

Rationale: G1 (Minor) geomagnetic storming is likely on 17 Oct due to
glancing CME effects from events that left the Sun on 12/13 Oct.

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 Oct 17-Oct 19 2025

              Oct 17  Oct 18  Oct 19
S1 or greater   10%     10%      5%

Rationale: There is a slight chance for a greater than 10 MeV proton
event above the S1 (Minor) levels through 18 Oct.

C. NOAA Radio Blackout Activity and Forecast

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Oct 16 2025 1408 UTC.

Radio Blackout Forecast for Oct 17-Oct 19 2025

              Oct 17        Oct 18        Oct 19
R1-R2           60%           60%           40%
R3 or greater   15%           15%            5%

Rationale: Minor to moderate (R1-R2) radio blackouts are likely through
18 Oct, with a slight chance for an isolated R3 (Strong) event, due to
the current and potential flare activity of Regions 4246 and 4248.
Probabilities decrease slightly on 19 Oct as AR 4246 rotates beyond the
western limb.