:Product: 04181230forecast_discussion.txt
:Issued: 2014 Apr 18 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity

.24 hr Summary...
Solar activity was at low levels. Region 2036 (S16W34, Dhc/beta-gamma)
continued to be the most active region on the visible disk, producing a
C4/Sf flare at 18/0809 UTC, which was the largest flare of the period.
Region 2034 (N04W32, Ekc/beta) exhibited moderate growth through out the
period, with Region 2035 (S15W11, Ekc/beta-gamma) following suit,
showing decent growth as well. Although Region 2036 continued to be the
most active, it began to show signs of decay, decreasing from over 510
millionths in area to near 390 millionths. The remaining spot groups
were either stable or exhibited slight decay.

.Forecast...
Solar activity is likely to be moderate (R1-Minor) for the next three
days (18 - 20 Apr) due to enhanced solar region complexity.

Energetic Particle

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

.Forecast...
The greater than 2 MeV electron flux at geosynchronous orbit is expected
to be at normal levels for the next three days (18 - 20 Apr). The
greater than 10 MeV proton flux at geosynchronous orbit is likely to
be at background levels (Below S1-Minor), though a slight chance of
protons has been added to the forecast during the period due to the
complexity of regions moving towards the West limb.

Solar Wind

.24 hr Summary...
Solar wind parameters, measured at the ACE spacecraft, indicated a
fairly stable solar wind environment. Solar wind speeds increased
steadily from approximately 385 km/s to near 430 km/s. IMF Bt wavered
slightly but remained fairly consistent near 6 nT. Bz was variable for
most of the period, but settled to near 4 nT by the end of the period,
and the Phi angle remained in a mostly positive (away) orientation.

.Forecast...
Solar wind enhancements, including modest speed and Bt increases, are
expected for the remainder of day one (18 Apr) due to potential
recurrent activity. Increased Bt and possible southward Bz are expected
on day two (19 Apr) with the anticipated arrival of the two faint/slow
CMEs from 15/16 Apr, believed to be on the Sun-Earth line. Late on day
two, the arrival of a third CME is expected to begin with a modest
increase in speed and density at onset, as well as a magnetic response.

Geospace

.24 hr Summary...
The geomagnetic field was quiet with an isolated unsettled period from
17/1500 - 1800 UTC.

.Forecast...
The geomagnetic field is expected to be quiet to unsettled for the
remainder of day one (18 Apr) and the first half of day two (19 Apr) in
response to possible recurrent enhancements in solar wind parameters, as
well as two weak CMEs from 15/16 Apr embedded in the ambient solar wind.
Active conditions are expected late on day two, and as high as minor
(NOAA Scale G1 - minor) storm levels on day three (20 Apr) with the
arrival of the third CME.