:Product: Weekly Highlights and Forecasts
:Issued: 2016 Apr 18 0325 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
11 - 17 April 2016

Solar activity was at low levels throughout the period. Region 2529
(N09, L=342, class/area Eki/850 on 11 Apr) produced all of the
C-class activity, the largest event a C5/Sf at 16/1958 UTC. An
associated CME was observed off the west limb but was determined not
to be Earth-directed.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal levels on 11 and 12 April. High levels were reached from
13-18 April following coronal hole high speed stream (CH HSS)
effects.

Geomagnetic field activity was at quiet levels on 11 April.
Unsettled to minor storm conditions were observed on 12-14 April due
to effects from a negative polarity CH HSS. Active conditions
continued into early 15 April but decreased to mostly quiet levels
through midday on 16 April. A weak CME moved through late on 16
April increasing activity to unsettled to active levels. Quiet to
active conditions continued into 17 April as CME effects subsided
and a co-rotating interaction region (CIR) ahead of an approaching
positive polarity CH HSS.

Forecast of Solar and Geomagnetic Activity
18 April - 14 May 2016

Solar activity is expected to be low with a slight chance for
M-class flares on 18-20 April. As Region 2529 exits the west limb,
activity is expected to decrease to very low levels with a chance
for C-class activity from 21 April to 02 May. Low levels are
expected to return from 03-14 May due to the return of old Region
2529.

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 with the exception of
26-28 April, 01-03 May and 10-13 April following recurrent CH HSS
events.

Geomagnetic field activity is expected to be unsettled to active on
18-19 April followed with quiet to unsettled levels on 20 April due
to effects from a positive polarity CH HSS. Mostly quiet conditions
are expected on 21-22 April. Unsettled conditions are expected on
23-26 April with isolated active periods likely due to a second
recurrent, positive polarity CH HSS. Mostly quiet conditions are
expected from 27-28 April. Unsettled to active conditions are
anticipated on 29-30 April with minor storm periods likely on 29
April as a negative polarity HSS becomes geoeffective. Mostly quiet
conditions are expected from 01-08 May with the exception of
possible unsettled to active periods on 04 May due to an SSBC that
has affected us the last few rotations. Unsettled to active
conditions are expected on 09-11 May with minor storm periods likely
as a recurrent negative polarity CH HSS moves into geoeffective
position. Mostly quiet conditions are expected on 12-13 May followed
by possible unsettled to active conditions on 14 May as a CIR
impacts the Earth.