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04251230forecast_discussion.txt
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2014-04-25
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:Product: 04251230forecast_discussion.txt
:Issued: 2014 Apr 25 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity
.24 hr Summary...
Solar activity reached high levels due an impulsive X1 X-ray event
observed at 25/0027 UTC from beyond the west limb. This event appears to
have originated in the vicinity of old Region 2035 (S13, L=224) which
rotated around the west limb early on 23 April. Associated with this
event were Type II radio emissions (estimated shock velocity of 753
km/s) and moderate to strong discrete frequency radio emissions to
include an 1100 sfu 10cm burst (2695 MHz) and a 43,000 sfu burst
recorded on 245 MHz. Shortly after the event, LASCO C2 and C3 imagery
observed a coronal mass ejection (CME) lifting off the west limb at
25/0048 UTC and 25/0130 UTC, respectively. Due to the location of this
event around the west limb, the bulk of this CME is not expected to
impact Earth.
The five spotted regions on the disk were quiet and either exhibited
little change or slight decay. No new regions were numbered. In addition
to the CME mentioned earlier, a few narrow CMEs were observed with no
Earth-directed component visible.
.Forecast...
Solar activity is expected to be at low levels for days one and two
(25-26 Apr), with a chance for M-class flares (NOAA Scale R1/R2 -
Minor/Moderate). Low levels are likely for day three (27 Apr) with a
slight chance for M-class activity.
Energetic Particle
.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 at geosynchronous orbit is expected
to be at normal to moderate levels for the forecast period (25-27 Apr).
The greater than 10 MeV proton flux at geosynchronous orbit is also
expected to remain at nominal levels for the forecast period.
Solar Wind
.24 hr Summary...
Solar wind parameters, measured at the ACE spacecraft, indicated the
continued influence of a weak, recurrent disturbance in the solar wind
environment. Solar wind speeds averaged ~450 km/s through about 25/0930
UTC when a gradual decrease to end-of-period speeds of near 400 km/s was
observed. IMF Bt ranged between 2 to 6 nT while the Bz component varied
between +4 to -5nT intermittently. The Phi component oscillated between
a positive (away) and negative (toward) orientation through about
25/0200 UTC when Phi settled into a mostly negative sector.
.Forecast...
The negative polarity solar wind feature is forecast to continue to
influence the solar wind environment for day one (25 Apr). Wind speeds
near 500 km/s are expected with intermittent southward Bz as well. A
return to nominal conditions is forecast for days two and three (26-27
Apr).
Geospace
.24 hr Summary...
The geomagnetic field was at quiet to unsettled levels.
.Forecast...
Quiet to unsettled conditions are expected again for day one (25 Apr)
due to the weak recurrent negative polarity solar wind feature. Quiet
conditions are forecast for days two and three (26-27 Apr).