:Product: Weekly Highlights and Forecasts
:Issued: 2012 Apr 23 1405 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
16 - 22 April 2012

Solar activity was at low to moderate levels. Moderate levels were
reached on 16 April with an M1.7 flare from Region 1461 (N13, L=070,
class/area Hsx/090 on 18 April) that occurred at 1745 UTC. Low
levels were observed from 17-22 April. On 18 April, Region 1463
(S26, L=160, class/area Cso/100 on 20 April) produced a C8.9/Sf
flare at 1239 UTC with an associated coronal mass ejection (CME) and
a C5.3 flare with an associated Type II (est. 621 km/s) and Type IV
radio sweeps. On 19 April, a C7.0 flare occurred at 1126 UTC with an
associated Type II and Type IV radio sweeps and a non-geoeffective
CME off the west limb. This event was likely from old Region 1455
(N06, L=206, class/area Fsi/200 on 16 April). Region 1462 (S25,
L=141, class/area Dho/410 on 20 April) produced a C1.8 flare at 1515
UTC with an associated CME on 19 April as well. Only low level
C-class flares were observed for the rest of the summary period.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
high levels on 16 and 17 April. Moderate levels were observed on
18,19, and 21 April while normal levels were observed on 20 and 22
April.

Geomagnetic field activity was mostly quiet, with brief intermittent
periods of unsettled and active levels on several days due to
nighttime effects and southward Bz. A solar sector boundary crossing
was observed on 20 April, and a weak glancing blow CME occurred on
21 April, again producing unsettled to active periods briefly.

Forecast of Solar and Geomagnetic Activity
23 April - 19 May 2012

Solar activity is expected to be at very low to low levels with the
slight chance for M-class flares during the period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at normal to moderate levels from the beginning of
the period on 23 April, and persist through 10 May. Flux values are
forecast to increase to high levels from 11-14 May due to a coronal
hole (CH) high speed stream. From 15 May through the end of the
period on the 19th, values are expected to return to moderate or
lower levels.

Geomagnetic field activity is expected to begin the period at
unsettled and active levels, as the result of a few weak CMEs along
with effects from a negative polarity CH. Conditions should settle
to mostly quiet levels from 26 April through 08 May, before
increasing to active levels with the chance for a minor storm on
09-11 May. Mostly active conditions are expected 14-15 May. The
increases in activity are expected from a pair of negative polarity
coronal holes. Mostly quiet levels are expected in between the two
features on 12 and 13 May, and again from 16-19 May to close out the
period.