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Weekly Highlights of Solar and Geomagnetic Activity, 29 April - 05 May 2013
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SWPC.We...@noaa.gov
May 6, 2013, 11:31:03 AM5/6/13
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:Product: Weekly Highlights and Forecasts
:Issued: 2013 May 06 0122 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/weekly.html
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
29 April - 05 May 2013
Solar activity reached high levels this week when Region 1739 (N13,
L=75, class/area=Dac/150 on 03 May) appeared on the east limb and
unleashed an M5/Sf flare on 03 May at 1732Z. The flare was
accompaned by Type II (1297 km/s) and Type IV radio emissions. A
coronal mass ejection (CME) was subsequently observed in LASCO/C2
coronagraph imagery at 03/1748Z and also in STEREO-A and B COR2
imagery. Region 1739 was also responsible for an M1/Sf flare at
05/1756Z. The most prolific active region of the week was, by far,
Region 1731 (N09, L=187, class/area=Dkc/420 on 28 Apr) with 17
C-class and two M-class flares to its credit. By 30 Apr, Region 1731
had developed beta-gamma-delta magnetic characteristics which it
mainteined through 03 May. During this period it produced an M1/1n
flare at 02/0510Z and a long duration M1/2n flare at 03/1655Z. The
02 May event was associated with a tenflare (159 sfu), a Type II
emission (703 km/s), and a CME first seen in LASCO/C2 imagery at
02/0524Z. The majority of the ejecta was directed north of the
ecliptic, but output from the WSA-Enlil model suggested a possible
scrape from the CME on 06 May. The 03 May event was not associated
with a CME.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at
high levels on 29-30 Apr and 03-04 May.
Geomagnetic field activity reached ensettled to active levels
beginning late on 30 Apr and lasting through 02 May. This activity
was in response to the presence of a recurrent negative polarity
coronal hole high speed stream. On 01 May, activity reached major
storm levels at high latitudes. Activity returned to quiet levels
early on 02 May. Conditions were quiet, with the exception of one
unsettled period during the latter half of 05 May with the arrival
of a corotating interaction region in advance of a positive polarity
recurrent coronal hole high speed stream.
Forecast of Solar and Geomagnetic Activity
06 May - 01 June 2013
Solar activity is expected to be at low levels with a chance for an
isolated moderate or greater event for the extent of the outlook
period.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be high on 8-10 May and again on 24-31 May in response
to recurrent coronal hole high speed streams.
Geomagnetic field activity is expected to be quiet to unsettled for
the majority of the outlook period. Active levels are possible on
21-23 May in response to a recurrent coronal hole high speed stream.
:Issued: 2013 May 06 0122 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/weekly.html
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
29 April - 05 May 2013
Solar activity reached high levels this week when Region 1739 (N13,
L=75, class/area=Dac/150 on 03 May) appeared on the east limb and
unleashed an M5/Sf flare on 03 May at 1732Z. The flare was
accompaned by Type II (1297 km/s) and Type IV radio emissions. A
coronal mass ejection (CME) was subsequently observed in LASCO/C2
coronagraph imagery at 03/1748Z and also in STEREO-A and B COR2
imagery. Region 1739 was also responsible for an M1/Sf flare at
05/1756Z. The most prolific active region of the week was, by far,
Region 1731 (N09, L=187, class/area=Dkc/420 on 28 Apr) with 17
C-class and two M-class flares to its credit. By 30 Apr, Region 1731
had developed beta-gamma-delta magnetic characteristics which it
mainteined through 03 May. During this period it produced an M1/1n
flare at 02/0510Z and a long duration M1/2n flare at 03/1655Z. The
02 May event was associated with a tenflare (159 sfu), a Type II
emission (703 km/s), and a CME first seen in LASCO/C2 imagery at
02/0524Z. The majority of the ejecta was directed north of the
ecliptic, but output from the WSA-Enlil model suggested a possible
scrape from the CME on 06 May. The 03 May event was not associated
with a CME.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at
high levels on 29-30 Apr and 03-04 May.
Geomagnetic field activity reached ensettled to active levels
beginning late on 30 Apr and lasting through 02 May. This activity
was in response to the presence of a recurrent negative polarity
coronal hole high speed stream. On 01 May, activity reached major
storm levels at high latitudes. Activity returned to quiet levels
early on 02 May. Conditions were quiet, with the exception of one
unsettled period during the latter half of 05 May with the arrival
of a corotating interaction region in advance of a positive polarity
recurrent coronal hole high speed stream.
Forecast of Solar and Geomagnetic Activity
06 May - 01 June 2013
Solar activity is expected to be at low levels with a chance for an
isolated moderate or greater event for the extent of the outlook
period.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be high on 8-10 May and again on 24-31 May in response
to recurrent coronal hole high speed streams.
Geomagnetic field activity is expected to be quiet to unsettled for
the majority of the outlook period. Active levels are possible on
21-23 May in response to a recurrent coronal hole high speed stream.
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