Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
964
FXXX10 KWNP 041231
DAYTDF
:Product: 3-Day Forecast
:Issued: 2026 Jun 04 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 Jun 04-Jun 06 2026 is 7.00 (NOAA Scale
G3).
NOAA Kp index breakdown Jun 04-Jun 06 2026
Jun 04 Jun 05 Jun 06
00-03UT 2.67 7.00 (G3) 4.33
03-06UT 2.67 6.33 (G2) 3.67
06-09UT 1.00 6.00 (G2) 2.67
09-12UT 2.67 4.67 (G1) 2.67
12-15UT 3.67 4.33 3.00
15-18UT 6.33 (G2) 4.67 (G1) 3.33
18-21UT 6.67 (G3) 5.00 (G1) 4.00
21-00UT 5.67 (G2) 4.33 3.67
Rationale: G2-G3 (Moderate-Strong) geomagnetic storming conditions are
anticipated on 04-05 June due to the arrival of several CMEs that left
the Sun on 03 June. Conditions are expected to wane into G1 (Minor)
storming conditions by the end of 05 Jun.
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 04-Jun 06 2026
Jun 04 Jun 05 Jun 06
S1 or greater 10% 10% 10%
Rationale: There is a slight chance for S1 (Minor) or greater solar
radiation storms through 06 Jun due to the anticipated arrival of the
above CMEs as well as the flaring potential of the visible disk.
C. NOAA Radio Blackout Activity and Forecast
No radio blackouts were observed over the past 24 hours.
Radio Blackout Forecast for Jun 04-Jun 06 2026
Jun 04 Jun 05 Jun 06
R1-R2 60% 60% 60%
R3 or greater 15% 15% 15%
Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely, with a
slight chance for R3 (Strong) events, through 06 Jun due to the flaring
potential of the visible disk.