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04211230forecast_discussion.txt
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2014-04-21
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:Product: 04211230forecast_discussion.txt
:Issued: 2014 Apr 21 1235 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity
.24 hr Summary...
Occasional low-level C-class flares kept activity at low levels. The
three most magnetically complex regions on the disk, Regions 2034, 2035
and 2036, each contributed low-level C-class events.
The largest event of the period was a C2/Sf flare at 20/1338 UTC from
Region 2035 (S15W52, Eki/beta-gamma). The region exhibited some
consolidation in the extreme northern portion of the region, but
otherwise was little changed. Region 2034 (N05W74, Eki/beta-gamma
produced a long duration C1 event at 21/0108 UTC. Some slight spot
development was observed in the intermediate portion of the region.
Region 2036 (S17W75, Esi/beta-gamma) produced three C1 events during the
period. Some intermediate spot decay was seen in the region.
The remainder of the spotted regions were little changed the past 24
hours. No new regions were numbered. No Earth-directed CMEs were
detected.
.Forecast...
C-class activity is expected to continue through the forecast period
keeping solar activity at predominately low levels for the next three
days (21-23 Apr). Further moderate (R1-minor) activity is likely on 21
Apr with a slight chance for high levels (R3-strong) before diminishing
to only a chance for R1-minor activity for 22-23 Apr as the large,
complex regions exit around the west limb.
Energetic Particle
.24 hr Summary...
The greater than 2 MeV electron flux at geosynchronous orbit was at
normal to moderate levels for the period. The 10 Mev greater than 10 pfu
proton event (S1-minor) which began on 18/1525 UTC, reached a maximum of
58 pfu at 19/0105 UTC and decayed below event threshold at 20/1155 UTC.
Proton flux levels remained enhanced, but decaying, through the period.
.Forecast...
The greater than 2 MeV electron flux at geosynchronous orbit is expected
to be at normal to moderate levels for the forecast period. The greater
than 10 MeV proton flux at geosynchronous orbit is expected to be
elevated, but below the 10 pfu threshold through day one (21 Apr). Flux
levels are expected to return to nominal levels by days two and three
(21-22 Apr).
Solar Wind
.24 hr Summary...
ACE satellite observations for the first 12 hours of period recorded
solar winds at an average of about 650 km/s. The second half of the
period saw a gradual decline in speeds to end the period near 575 km/s.
IMF Bt ranged from 17 nT early with a gradual decline 6 nT at periods
end. The Bz component varied between +16 to -8 nT through about 21/0000
UTC. Through the remainder of the period, variations did not exceed +/-
5 nT. The phi angle was highly variable, rotating between positive
(away) and negative (towards) sectors throughout the period.
.Forecast...
The current disturbed conditions are expected to slowly diminish over
the next three days (21-23 Apr). A weak negative coronal hole high
speed stream may keep conditions from returning to a purely nominal
state.
Geospace
.24 hr Summary...
Geomagnetic field activity was influenced by CME effects through the 24
hour period. Activity levels ranged from minor storm intervals early in
period from 20/1200-1500 UTC, active levels from 20/1500 - 21/0600 UTC
and unsettled levels through the end of the period.
.Forecast...
Unsettled to active levels are expected for the remainder of day one (21
Apr) with mostly quiet to unsettled levels expected on days two and
three (22-23 Apr).