:Product: Weekly Highlights and Forecasts
:Issued: 2016 Oct 17 0400 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
10 - 16 October 2016

Solar activity was low very low on 10-11 Oct and 15-16 Oct. Activity
was at low levels on 12-14 Oct, with the strongest flare, a C1 at
13/2105 UTC, occurring from around the east limb. Region 2599 (S15,
L=144, class/area Cko/460 on 05 Oct) was the only numbered region to
produce a C-class flare; a C1/Sf at 12/1155 UTC. On 14 Oct, two
filament eruptions were observed in GONG and SDO/AIA imagery in the
NE quadrant. Around 14/1500 UTC, a five degree long filament erupted
along a channel centered near N01E30. Later, around 14/2230 UTC, a
ten degree long filament erupted along a channel centered near
N09E45. No associated CME signatures were observed in available
coronagraph imagery.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal background levels on 13-14 Oct. Moderate levels were observed
on 11-12 Oct. High levels were reached on 10 Oct, and 14-16 Oct.

Geomagnetic field activity during the reporting period ranged from
quiet to major storm (G2-Moderate) levels. Quiet to unsettled levels
were observed on 10 Oct and tapered down to quiet levels until late
on 12 Oct, when unsettled levels were observed from the onset of the
08 Oct CME. Unsettled to levels continued into 13 Oct, increasing to
G2 (Moderate) storm levels late on 13 Oct and into early on 14 Oct.
Minor (G1-Minor) storm levels gave way to unsettled and then quiet
conditions as 14 Oct progressed. Quiet to unsettled levels persisted
over 15-16 Oct, increasing to G1 (Minor) storm levels once again,
late on 16 Oct, in response to the onset of a negative polarity CH
HSS.

The solar wind environment was at near-background levels from 10-12
Oct. Late on 12 Oct, an enhancement was observed after 12/2120 UTC,
marking the arrival of a CME from a filament eruption centered near
N38E40 on 08 Oct. During the sheath, a moderate increase in solar
wind speed was observed, increasing from an ambient 370 km/s to an
enhanced 400-445 km/s. Total magnetic field strength ranged from
2-10 nT. The Bz component displayed a primarily northward
orientation. Around 13/0520 UTC, enhancements in the solar wind
suggested the transitions from the sheath to the CME driver. Density
dropped and total magnetic field strength steadily increased to a
peak of 24 nT around 13/2200 UTC. The Bz component rotated in a
sustained far southward orientation, with a slow rotation northward
beginning around 13/2200 UTC. Solar wind speeds were relatively
modest, ranging from around 380-450 km/s during the event. Solar
wind parameters slowly declined towards background conditions
through 15 Oct. Early on 16 Oct, the onset of a negative polarity CH
HSS was observed. Solar wind speeds steadily increased, reaching
peak wind speeds around 750 km/s as the reporting period ended.



Forecast of Solar and Geomagnetic Activity
17 October - 12 November 2016

Solar activity is expected to be very low with a 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 reach moderate levels on 21-23 Oct and 7-11 Nov; high
levels on 17-20 Oct, 25-26, 30 Oct - 06 Nov, and 12 Nov; very high
levels on 27-29 Oct. Enhancement in the 2 MeV electron flux is
anticipated as a result of multiple, recurrent CH HSSs.

Geomagnetic field activity is likely to reach major storm
(G2-Moderate) levels on 17 Oct due to elevated winds from the
influence of a negative polarity coronal hole. Conditions are
expected to decrease to active by 18 Oct, and quiet to unsettled
conditions on 19 Oct, as the negative polarity CH HSS wanes. Active
conditions are again likely on 22 Oct with the onset of recurrent,
positive polarity CH HSS. Conditions are forecast to reach minor
(G1-Minor) storm levels on 23 Oct and G2 storm levels from 24-26 Oct
as solar wind speeds expected to climb. G1 storm conditions are
likely from 27-31 Oct, and active conditions by 01 Nov, as the CH
HSS slowly subsides. Quiet conditions are likely from 02-10 Nov
under an ambient solar wind regime. Unsettled conditions on 11 Nov
are likely to give way to G1 storm conditions on 12 Nov as another
negative polarity CH HSS is anticipated to enhance the near-Earth
space environment.