237
FXXX10 KWNP 031231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Dec 03 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 Dec 03-Dec 05 2025 is 5.67 (NOAA Scale
G2).

NOAA Kp index breakdown Dec 03-Dec 05 2025

             Dec 03       Dec 04       Dec 05
00-03UT       1.67         4.67 (G1)    4.33
03-06UT       2.67         4.67 (G1)    4.33
06-09UT       2.00         5.67 (G2)    4.33
09-12UT       3.00         4.33         4.00
12-15UT       3.67         3.67         3.67
15-18UT       3.67         3.67         3.33
18-21UT       5.00 (G1)    4.00         3.00
21-00UT       5.67 (G2)    4.33         3.33

Rationale: Unsettled to active levels are likely to give way to G1-G2
(Minor-Moderate) storming periods by late 03 Dec due to combined CME
shock effects and the arrival of fast solar wind. G1-G2 (Minor-Moderate)
storming is then likely to continue into 04 Dec. It should also be noted
that a chance (25%) for isolated periods of G3 (Strong) geomagnetic
storming will exist on 03 and 04 Dec, especially if the corotating
interaction region ahead of the high speed stream arrives with embedded
shock from the 01 Dec CME.

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 03-Dec 05 2025

              Dec 03  Dec 04  Dec 05
S1 or greater   15%     15%     15%

Rationale: The flare potential currently exhibited by Earth-facing
active regions will keep 10 MeV protons at a slight risk (15%) of
reaching the 10 particle flux unit threshold through 05 Dec.


C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Dec 03-Dec 05 2025

              Dec 03        Dec 04        Dec 05
R1-R2           75%           75%           75%
R3 or greater   30%           30%           30%

Rationale: Isolated to occasional R1-R2 (Minor-Moderate) radio blackouts
are expected (75%) through 05 Dec, with a chance for a R3 (Strong) event
(30%), given past flare history and the potential of current active
regions on the disk.

- WC