175
FXXX10 KWNP 281231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 May 28 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 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for May 28-May 30 2026 is 3.33 (below NOAA
Scale levels).

NOAA Kp index breakdown May 28-May 30 2026

             May 28       May 29       May 30
00-03UT       2.00         3.33         2.00
03-06UT       2.33         3.00         2.00
06-09UT       2.67         1.67         1.33
09-12UT       3.67         2.00         1.00
12-15UT       2.00         2.00         1.00
15-18UT       1.67         1.67         1.67
18-21UT       2.67         2.33         2.33
21-00UT       1.67         2.33         2.33

Rationale: No G1 (Minor) or greater geomagnetic storms are expected.

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 May 28-May 30 2026

              May 28  May 29  May 30
S1 or greater    5%      5%      5%

Rationale: No S1 (Minor) or greater solar radiation storms are expected.


C. NOAA Radio Blackout Activity and Forecast

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for May 28-May 30 2026

              May 28        May 29        May 30
R1-R2           40%           40%           40%
R3 or greater    5%            5%            5%

Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
through 30 May.