946
FXXX10 KWNP 181231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Jul 18 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 4 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Jul 18-Jul 20 2025 is 3.67 (below NOAA
Scale levels).

NOAA Kp index breakdown Jul 18-Jul 20 2025

             Jul 18       Jul 19       Jul 20
00-03UT       2.00         3.00         1.67
03-06UT       1.00         3.00         3.00
06-09UT       2.00         2.67         2.67
09-12UT       2.67         2.67         1.67
12-15UT       3.67         1.67         1.33
15-18UT       2.00         1.67         0.67
18-21UT       2.33         1.00         1.67
21-00UT       2.67         2.00         2.00

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 Jul 18-Jul 20 2025

              Jul 18  Jul 19  Jul 20
S1 or greater   10%     10%     10%

Rationale: There is a slight chance for the greater than 10 MeV proton
flux to reach S1 (Minor) solar radiation storm levels over 18-20 Jul.

C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Jul 18-Jul 20 2025

              Jul 18        Jul 19        Jul 20
R1-R2           60%           60%           60%
R3 or greater   15%           15%           15%

Rationale: Low-level solar activity is expected to continue, with
M-class (R1-R2/Minor-Moderate) flares likely, and a slight chance for an
isolated X-class (R3-Strong) flare over 18-20 Jul.