:Product: Weekly Highlights and Forecasts
:Issued: 2016 Sep 12 0323 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
05 - 11 September 2016

Solar activity was at very low levels on 05-11 Sep. Region 2591
(N05, L=144, Cro/025 on 11 Sep) produced a B9.6 flare at 10/1920
UTC, the strongest of the period. No Earth-directed CMEs were
observed were observed during the period.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
very high levels on 05 Sep and high levels from 06-11 Sep due to CH
HSS influence. The largest flux value of the period was 56,842 pfu
observed at 05/1815 UTC.

Geomagnetic field activity was at quiet to minor storm levels on 05
Sep due to a period of prolonged southward Bz during the waning
phase of a CH HSS. Solar wind speed continued to decline over the
period from a high near 600 km/s to 340 km/s by the end of the
period. Activity decreased to quiet to active conditions on 06 Sep
and to quiet to unsettled conditions on 07 Sep. A final increase to
quiet to active conditions was observed on 08 Sep before quiet
conditions dominated for the remainder of the period.

Forecast of Solar and Geomagnetic Activity
12 September - 08 October 2016

Solar activity is expected to be at very low to low levels
throughout the forecast 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 on 12-20 Sep and 26-28
Sep. High levels expected on 21-25 Sep, 29 Sep - 01 Oct, and 06-08
Oct. Very high levels are likely between 02-05 Oct. High and very
high levels are anticipated to result from recurrent CH HSS events.

Geomagnetic field activity is expected to be at quiet to active
levels on 12 Sep as a solar sector boundary crossing is anticipated
to transition into a weak, negative polarity, CH HSS. As the CH HSS
influence wanes, quiet to unsettled levels are likely over 13-14
Sep. Quiet conditions are expected on 15-16 Sep under an ambient
solar wind environment. 17-21 Sep will likely to be at quiet to
active conditions as a negative polarity CH HSS influences the
near-Earth environment. Quiet conditions are again expected from
22-25 Sep. 26-27 Sep are likely to be at unsettled to active
conditions from a small, positive polarity, CH HSS. 28-30 Sep are
likely to see field active range from unsettled to major storm
levels from a strong, positive polarity, CH HSS. As the CH HSS
influence wanes, unsettled to minor storm levels are likely on 01
Oct and quiet to active levels are expected from 02-05 Oct. Quiet
conditions are expected to return over 06-08 Oct under a nominal
solar wind regime.