===================================
  Weekly Space Weather Highlights
===================================

Highlights of Solar and Geomagnetic Activity
15 - 21 May 2017

Solar activity was very low throughout the reporting period. Region
2659 (N14, L=038, class/area=Dao/040 on 21 May 2017) was the most
complex region; however, it has produced no significant flare
activity. No Earth-directed CMEs were observed in available
coronagraph imagery. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit ranged
from normal to high levels, with a peak flux of 13,000 pfu at
21/1710 UTC. Normal levels were observed on 15 May and moderate
levels were observed on 16-19 May. In response to a negative
polarity CH HSS, high levels were observed on 20-21 May. 

Geomagnetic field activity was at quiet to active levels. Quiet to
active levels were observed on 15 May. Conditions decreased to quiet
to unsettled levels on 16-17 May under nominal solar wind
conditions. A SSBC produced quiet to active levels on 18 May and
quiet to unsettled levels on 19 May. The subsequent onset of a
negative polarity CH HSS, with peak observed winds between 700-750
km/s, produced unsettled to active conditions on 20 May and quiet to
unsettled levels on 21 May. 

Forecast of Solar and Geomagnetic Activity
22 May - 17 June 2017

Solar activity is expected to be very low with a slight chance for
C-class flare activity throughout the outlook period. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to range from normal to very high levels. Moderate levels
are likely on 01-10 Jun and 12-15 Jun; high levels are likely on 22
May, 27-31 May, and 16-17 Jun; very high levels are likely on 23-26
May. Elevated levels of electrons are in response to multiple,
recurrent, CH HSSs. The remainder of the outlook period is likely to
observe normal background levels. 

Geomagnetic field activity is expected to be at quiet to G1 (Minor)
storm levels. Active conditions are likely on 22 May with unsettled
conditions likely on 23-24 May due to the waning effects of a
negative polarity CH HSS. Quiet conditions are then likely to
prevail from 25 May-09 Jun under a nominal solar wind regime. An
increase to active conditions is likely on 10-11 Jun from a positive
polarity CH HSS. Quiet conditions are again likely on 12-13 Jun. A
SSBC is expected to cause unsettled conditions on 14 Jun. A
subsequent negative polarity CH HSS is likely to cause active
conditions on 15 Jun, G1 (Minor) conditions on 16 Jun, then active
conditions as the CH HSS wanes on 17 Jun.