639
FXXX10 KWNP 180031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Jul 18 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 1 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Jul 18-Jul 20 2026 is 2.67 (below NOAA
Scale levels).

NOAA Kp index breakdown Jul 18-Jul 20 2026

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

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 Jul 18-Jul 20 2026

              Jul 18  Jul 19  Jul 20
S1 or greater    1%      1%      1%

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 Jul 18-Jul 20 2026

              Jul 18        Jul 19        Jul 20
R1-R2           15%           15%           15%
R3 or greater    1%            1%            1%

Rationale: There remains a slight chance for R1-R2 (Minor-Moderate)
radio blackouts over 18-20 Jul.