444
FXXX10 KWNP 271231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Jul 27 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 27-Jul 29 2026 is 3.67 (below NOAA
Scale levels).

NOAA Kp index breakdown Jul 27-Jul 29 2026

             Jul 27       Jul 28       Jul 29
00-03UT       1.67         3.67         2.67
03-06UT       1.00         3.33         2.00
06-09UT       2.00         2.00         2.00
09-12UT       1.33         3.00         2.00
12-15UT       1.67         3.33         2.00
15-18UT       1.33         2.00         2.00
18-21UT       1.33         3.33         2.00
21-00UT       3.67         3.00         2.33

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 27-Jul 29 2026

              Jul 27  Jul 28  Jul 29
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

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Jul 26 2026 1528 UTC.

Radio Blackout Forecast for Jul 27-Jul 29 2026

              Jul 27        Jul 28        Jul 29
R1-R2           40%           40%           40%
R3 or greater    1%            1%            1%

Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
on 27-29 Jul.