INFO FROM SIDC - RWC BELGIUM 2018 Aug 20 12:44UTC

Solar activity was very quiet with X-ray flux remaining below B level.
NOAA active region 2718 has decayed while the newly developing small
bipolar region in the East was numbered NOAA 2719.
X-ray flux is expected to remain below C level.

Around 5:00UT August 19, a minor but long duration A-flare from region 2718
was associated with an on disk dimming (5:40UT august 19), evidencing an
eruptive phenomenon. In SoHO/LASCO C2 coronagraph images a very narrow
(only around 10 degrees angular width) CME is visible from August 19 7:36UT
onwards, directed towards the South-West. It is also visible from Stereo A
COR2, also narrow and directed to the South-West from this viewpoint. From
the Stereo COR2 images a radial speed of around 1000 km/s may be estimated.
Given the narrow angular extent and the direction of the ejecta (no halo
character from Earth perspective), the bulk of this CME is expected to go
South of the Earth.

Proton flux levels were at background values and are expected to remain
so.

Solar wind conditions were indicative of the arrival of the expected high
speed stream from the transequatorial negative polarity coronal hole.
Solar wind speed reached a minimum of close to 400 km/s near the start of
the period and then started a steady increase to current values of over 650
km/s. Between 17UT and 8UT total magnetic field was enhanced reaching
values of close to 14nT, but the Bz component was mainly positive.
Meanwhile, total magnetic field has restored to below 5nT.
Solar wind speed is still expected to increase and is expected to remain
elevated for several days given the extent of the coronal hole. For the CME
of August 19 the bulk of the CME is expected to go South of the Earth but
there remains a possibility that a shock arrives at Earth. If this occurs
this is expected around midnight August 21/22 but its effect will be small
within the already elevated background solar wind conditions.
Geomagnetic conditions were mainly quiet to unsettled (K Dourbes and NOAA
Kp 1-3) with an isolated active period for Kp around midnight.
Geomagnetic conditions may reach active levels under the influence of the
high speed stream over the next days.