FXXX10 KWNP 181231

DAYTDF



:Product: 3-Day Forecast

:Issued: 2026 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 2 (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       1.00         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

through 20 Jul.



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

through 20 Jul.  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 is a slight chance for R1-R2 (Minor-Moderate) radio

blackouts through 20 Jul.