:Product: Forecast Discussion
:Issued: 2013 Jun 19 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity

.24 hr Summary...
Solar activity has been low for the past 24 hours. The largest event of
the period was a C8 flare at 19/0954 UTC from a region around the
southeast limb that has not migrated onto the visible disk. Region 1776
(N11W02) produced low level C-flare activity and continued to show signs
of growth. There were three coronal mass ejections (CMEs), from the
southwest limb, first observed in LASCO/C2 imagery at 18/1712 UTC;
19/0136 UTC; and 19/0336 UTC respectively. The last CME was associated
with a report by the Learmonth solar observatory in Australia as an
eruptive prominence on limb (EPL) beginning at 19/0238 UTC and ending at
19/0329 UTC. Forecasters do not anticipate these CMEs to be geoeffective
but analysis is ongoing to determine their potential trajectory.
        
.Forecast...
Solar activity is expected to be low with a chance for an M-class flare
for the next three days (19-21 Jun). 

Energetic Particles

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

.Forecast...
The greater than 2 MeV electron flux is expected to be at normal to
moderate levels for the next three days (19-21 Jun). The greater than
10 MeV proton flux is expected to remain at background levels for the
next three days (19-21 Jun).


Solar Wind

.24 hr Summary...
Solar wind parameters, as measured at the ACE spacecraft, were
indicative of a quiet background solar wind environment. Solar wind
speed reached a peak of 332 km/s during the period. The interplanetary
magnetic field Bt was steady at 6 nT but dropped as low as 1 nT for a
short period at 18/2020 UTC. The Bz component ranged between 5/-5 nT.
The phi angle remained oriented in a negative (toward) sector throughout
the period.

.Forecast...
Solar wind speed is expected to remain at background levels for days one
and two (19-20 Jun). Late on Day 3 (21 Jun), the initial onset of
coronal hole high-speed stream (CH HSS) effects from CH41 are expected
to be seen at ACE, with peak solar wind speeds near 600 km/s. The
density, temperature, and phi angle parameters are expected to be
consistent with typical CH signatures.

Geospace

.24 hr Summary...
The geomagnetic field was quiet.

.Forecast...
The geomagnetic field is expected to be at quiet levels on days one and
two (19-20 Jun). Activity is expected to increase on day three (21 Jun)
to quiet to active levels due to the onset of a CH HSS.