401
FXXX10 KWNP 270031
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Aug 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 1 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Aug 27-Aug 29 2026 is 5.67 (NOAA Scale
G2).

NOAA Kp index breakdown Aug 27-Aug 29 2026

             Aug 27       Aug 28       Aug 29
00-03UT       1.33         5.67 (G2)    5.67 (G2)
03-06UT       2.33         4.67 (G1)    4.67 (G1)
06-09UT       3.33         4.00         4.00
09-12UT       3.00         4.00         3.00
12-15UT       3.33         3.67         3.33
15-18UT       3.67         4.00         2.67
18-21UT       4.33         4.00         2.67
21-00UT       4.67 (G1)    4.67 (G1)    2.67

Rationale: Isolated G1-G2 (Minor-Moderate) geomagnetic storms are likely
through 29 Aug due to both CH HSS and CME arrival influences.

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 Aug 27-Aug 29 2026

              Aug 27  Aug 28  Aug 29
S1 or greater   10%     10%     10%

Rationale: There is a slight chance for S1 (Minor) or greater solar
radiation storms all three days.

C. NOAA Radio Blackout Activity and Forecast

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Aug 26 2026 0634 UTC.

Radio Blackout Forecast for Aug 27-Aug 29 2026

              Aug 27        Aug 28        Aug 29
R1-R2           55%           55%           55%
R3 or greater   15%           15%           15%

Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts
and a slight chance for R3 (Strong) or greater blackouts all three days.