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000
FXXX12 KWNP 241230
DAYDIS

:Product: Forecast Discussion
:Issued: 2013 May 24 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
#
#             Forecast Discussion
#
Solar Activity

.24 hr Summary...
Solar activity was at low levels.  The largest flares of the period were
a C3/Sf at 23/1450 UTC and a C3 at 23/1847 UTC, both from Region
1756 (S20E22, Ehi/beta-gamma).  A few low-level C-class flares were
observed from old Region 1736 (S08, L=139), still behind the eastern
limb and due to return on day one (24 May).  Region 1756 showed slight
growth early in the period, but began to show slight decay in the
trailer spot area at the time of this writing.  Region 1755 (N10E32,
Dsi/beta-gamma)  continued to show a slight decay trend, especially in
the trailer spot area.  The other regions on the disk were either stable
or decaying.  No Earth-directed coronal mass ejections (CMEs) were
observed during the period.

.Forecast...
Solar activity is expected to be low with a chance for M-class flares
and a slight chance for X-class flares for the next three days (24 - 26
May).

Energetic Particle

.24 hr Summary...
The greater than 10 MeV proton flux at geosynchronous orbit began in
NOAA Scale S2 (Moderate) Solar Radiation Storm conditions, but continued
to decrease throughout the period, decreasing to NOAA Scale S1 (Minor)
conditions at 24/0435 UTC.  The greater than 2 MeV electron flux at
geosynchronous orbit remains contaminated by the recent proton event and
were unreliable since 22/1420 UTC.

.Forecast...
The greater than 10 MeV proton flux is expected to remain above NOAA
Scale S1 (Minor) thresholds for day one (24 May), and likely into the
first part of day two (25 May).  There is a chance for a greater than 10
MeV proton event on day three (26 May).  The greater than 2 MeV electron
flux at geosynchronous orbit is likely to have unreliable readings until
the greater than 10 MeV proton flux returns to near-background values.

Solar Wind

.24 hr Summary...
Solar wind speed, measured at ACE, ranged from 400 km/s to 500 km/s.
Total magnetic field strength ranged from 4 nT to 8 nT while the Bz
component ranged from +6 nT to -6 nT.  The phi angle remained in a
negative (toward) solar sector.  ACE/SWEPAM data were suspect due to
proton contamination until around 23/1700 UTC, when the sensors began to
recover.

.Forecast...
Solar wind speeds are expected to become enhanced by mid to late day one
(24 May) due to a glancing blow from the 22 May partial-halo CME.
Conditions are expected to continue to be enhanced on days two and three
(25-26 May), due to a combination of continued CME effects followed by a
coronal hole high speed stream (CH HSS).

Geospace

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

.Forecast...
The geomagnetic field is expected to be quiet to unsettled through the
first half of day one (24 May).  By mid to late on day one, a glancing
blow from the 22 May CME is expected to impact the geomagnetic field
causing unsettled to active conditions with a chance for NOAA Scale G1
(Minor) Geomagnetic Storm conditions.  Unsettled to active levels are
expected to persist into day two (25 May) as CME effects wane and CH HSS
effects begin.  CH HSS effects are expected on day three (26 May),
causing predominately quiet to unsettled levels.