273
FXXX12 KWNP 120031
DAYDIS

:Product: Forecast Discussion
:Issued: 2026 Jun 12 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
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#             Forecast Discussion
#
Solar Activity


.24 hr Summary...
Solar activity remained at low levels with Region 4465 (N09E30,
Dhi/beta-gamma) being the source of the largest events of the
day: a long-duration C6.7/1f flare observed at 11/0002 UTC
and an impulsive C9.0 flare at 11/0828 UTC. The C6.7/1f flare was
accompanied by Type-II (est. velocity of 918 km/s) and Type-IV radio
bursts, and a partial halo CME Earth-directed.

The CME analysis indicated potential impact near-Earth starting early on
13 Jun. No other Earth-directed CMEs were observed in available
coronagraph imagery.

.Forecast...
Solar activity is expected to remain at low levels through 14 June, with
a high chance for M-class flares (R1-R2/Minor-Moderate) and a slight
chance for X-class flares (R3/Strong), mostly due to the flare potential
of Region 4465.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux at geosynchronous orbit continued
at low to moderate levels. The greater than 10 MeV proton flux at
geosynchronous orbit remained at background levels.

.Forecast...
The greater than 2 MeV electron flux is expected to remain at low to
moderate levels on 12 June, before rising to high levels on 13-14 June
in response to the high-speed stream effects. The greater than 10 MeV
proton flux is expected to remain at background levels through 14 June.

Solar Wind

.24 hr Summary...
Solar wind parameters indicated the arrival of the anticipated
corotating interaction region (CIR) around 11/1700 UTC, with the
increase of the speeds (from 375 up to 500 km/s) and enhancement of
total interplanetary magnetic field strength from 5 nT to 15 nT at the
end of the period. Two sustained periods of Bz negative were observed:
between 11/0350-0955 UTC and between 11/1835-2100 UTC. The later event,
associated with the increased speeds and densities from the CIR,
resulted in a minor geomagnetic storm. The phi angle became
predominantly oriented in the negative sector after 11/1600 UTC.

.Forecast...
Solar wind enhanced disturbances are expected to persist on 12 June, as
the high speed stream (HSS) associated to a negative coronal hole (-CH)
brings faster solar wind speeds to the Geospace. Elevated solar wind
conditions (driven by the -CH HSS) are expected to persist through 13
June, around which time additional disturbances are likely, due to
combining CME influences from the eruptions that departed the Sun on 09
June and 11 June.

Geospace

.24 hr Summary...
The geomagnetic field was at quiet to minor storm levels as a result of
a sustained southward Bz upon the arrival of the anticipated CIR
near-Earth.

.Forecast...
Geomagnetic field conditions are expected to reach G1 (Minor)
geomagnetic storming on 12 June under anticipated -CH HSS effects. G2
(Moderate) geomagnetic storming levels are likely on 13 June due to the
persistence of the high-speed stream and the arrival of the disturbances
caused by the CMEs that left the Sun on 09 and 11 June. G1 (Minor)
levels are likely on 14 June, as the CMEs effects wane.