079
FXXX10 KWNP 270031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2025 Jul 27 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 4 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Jul 27-Jul 29 2025 is 5.00 (NOAA Scale
G1).

NOAA Kp index breakdown Jul 27-Jul 29 2025

             Jul 27       Jul 28       Jul 29
00-03UT       2.00         3.00         1.67
03-06UT       2.00         3.00         1.33
06-09UT       3.67         3.00         1.33
09-12UT       5.00 (G1)    2.67         1.33
12-15UT       4.00         2.67         1.33
15-18UT       3.33         2.67         1.33
18-21UT       3.00         2.33         1.67
21-00UT       3.33         2.00         1.67

Rationale: G1 (Minor) geomagnetic storms are are likely on 27 Jun due to
anticipated passage of a CME that left the Sun on 23 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 27-Jul 29 2025

              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

No radio blackouts were observed over the past 24 hours.

Radio Blackout Forecast for Jul 27-Jul 29 2025

              Jul 27        Jul 28        Jul 29
R1-R2           40%           40%           40%
R3 or greater    5%            5%            5%

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