040
FXXX10 KWNP 181231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Jun 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 Jun 18-Jun 20 2026 is 4.00 (below NOAA
Scale levels).

NOAA Kp index breakdown Jun 18-Jun 20 2026

             Jun 18       Jun 19       Jun 20
00-03UT       2.00         3.00         3.00
03-06UT       1.67         4.00         3.67
06-09UT       0.67         3.67         2.67
09-12UT       2.00         3.00         2.33
12-15UT       1.67         3.00         2.00
15-18UT       1.33         2.00         2.00
18-21UT       1.33         1.67         2.33
21-00UT       2.67         3.00         3.00

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 Jun 18-Jun 20 2026

              Jun 18  Jun 19  Jun 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 Jun 18-Jun 20 2026

              Jun 18        Jun 19        Jun 20
R1-R2           10%           15%           15%
R3 or greater    1%            1%            1%

Rationale: There is a slight chance for R1-R2 (Minor-Moderate) radio
blackouts through 20 Jun.