Weekly Highlights of Solar and Geomagnetic Activity, 06 - 12 May 2013

[SWPC.We...@noaa.gov]

:Product: Weekly Highlights and Forecasts
:Issued: 2013 May 13 0755 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
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# Weekly Highlights and Forecasts
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Highlights of Solar and Geomagnetic Activity
06 - 12 May 2013

Solar activity was low for the first half of the week, and moderate
for the second. After a slow start with only low-level C-class
flares from the regions on the disk, activity jumped up to moderate
levels on 10 May when Region 1745 (N14, L=336, class/area=Ekc/600 on
12 May) unleashed an M3.9 flare at 0057Z shortly after rotating
around the east limb. Later that same day, Region 1745 produced an
M1.3 flare at 1256Z. Region 1745 and 1744 (N05, L=259,
class/area=Dai/190 on 12 May) were the most productive regions on
the disk during the week, with 10 C-flares each to their credit.
Region 1744 was responsible for the largest C-class flare of the
week, a C9.0 at 09/2316, immediately preceding the beginning of
moderate activity. The 11th was relatively quiet; the largest flare
was a C8.0 from Region 1746 (S27, L=337, class/area=Dhi/270 on 12
May) shortly after it emerged on the disk. However, there was a 16
degree filament eruption centered near N39W50 which began at
11/2230Z. The resulting CME was visible in LASCO/C2 coronagraph
imagery by 12/0000Z. WSA-Enlil output suggested this CME may brush
past Earth late on the 14th or early on the 15th. Moderate activity
returned on 12 April with two M-class events, an M1.9 at 2032Z and
an M1.2 at 2244Z, from a newly emerged region beyond the east limb.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal to moderate levels all week.

Geomagnetic field activity was at quiet to unsettled levels all
week. A positive polarity recurrent coronal hole high speed stream
brought unsettled conditions for the first three days of the week.
The remainder of the week saw quiet geomagnetic conditions.

Forecast of Solar and Geomagnetic Activity
13 May - 08 June 2013

Solar activity is expected to be at low levels with moderate
activity likely and a chance for high activity levels throughout the
forecast period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at high levels begiining on 24 May and lasting
through 31 May in response to a recurrent coronal hole high speed
stream. Normal to moderate levels are expected for the balance of
the period.

Geomagnetic field activity is expected to be at quiet to unsettled
levels through the period with the exception of 15-16, 21-23. amd
28-29 May. Unsettled to active levels are expected on 15-16 May with
the arrival of a glancing blow from the CME observed on 12 May.
Conditions are expected to be unsettled to active on 21-23 May, and
28-29 May with in response to recurrent coronal hole high speed
stream. Another high speed stream may bring unsettled conditions on
2-4 June.