778
FXXX10 KWNP 310031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Dec 31 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 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Dec 31-Jan 02 2026 is 5.00 (NOAA Scale
G1).

NOAA Kp index breakdown Dec 31-Jan 02 2026

             Dec 31       Jan 01       Jan 02
00-03UT       1.67         5.00 (G1)    3.67
03-06UT       1.67         5.00 (G1)    3.67
06-09UT       2.00         3.67         3.33
09-12UT       2.00         3.33         3.33
12-15UT       2.33         3.33         3.00
15-18UT       2.67         4.33         3.00
18-21UT       3.33         4.00         3.00
21-00UT       4.33         3.33         3.00

Rationale: G1 (Minor) or greater geomagnetic storms are possible on 01
Jan.

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 Dec 31-Jan 02 2026

              Dec 31  Jan 01  Jan 02
S1 or greater   15%     15%     15%

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 Dec 31-Jan 02 2026

              Dec 31        Jan 01        Jan 02
R1-R2           60%           60%           60%
R3 or greater   25%           25%           25%

Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a
chance for R3 (Strong) or greater events, on 31 Dec-02 Jan.