039
FXXX10 KWNP 301231
DAYTDF

:Product: 3-Day Forecast
:Issued: 2026 Jun 30 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 1 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Jun 30-Jul 02 2026 is 5.00 (NOAA Scale
G1).

NOAA Kp index breakdown Jun 30-Jul 02 2026

             Jun 30       Jul 01       Jul 02
00-03UT       0.33         2.00         3.33
03-06UT       0.67         1.67         4.00
06-09UT       0.67         1.67         3.00
09-12UT       0.33         1.67         2.67
12-15UT       3.00         2.00         2.00
15-18UT       5.00 (G1)    2.33         2.00
18-21UT       4.67 (G1)    3.67         2.00
21-00UT       2.67         4.33         1.67

Rationale: G1 (Minor) storm conditions are likely 30 Jun with the
anticipated arrival of the 26 Jun CME.


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 30-Jul 02 2026

              Jun 30  Jul 01  Jul 02
S1 or greater    5%      5%     10%

Rationale: The probability for S1 (Minor) or greater solar radiation
storms increases beginning 02 Jul as Regions 4478  and 4479 continue to
develop and move westward into a more favorable position to connect with
Earth.


C. NOAA Radio Blackout Activity and Forecast

Radio blackouts reaching the R1 levels were observed over the past 24
hours. The largest was at Jun 29 2026 2140 UTC.

Radio Blackout Forecast for Jun 30-Jul 02 2026

              Jun 30        Jul 01        Jul 02
R1-R2           60%           60%           60%
R3 or greater   10%           10%           10%

Rationale: Isolated R1-R2 (Minor-Moderate) radio blackouts are likely
with a slight chance for R3 (Strong) or greater events primarily due to
the potential of Regions 4478 and 4479.