:Product: Weekly Highlights and Forecasts
:Issued: 2016 Dec 12 0110 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 December 2016

Solar activity ranged from very low to low over the period. Very low
levels were observed on 06-09 December and again on 11 December. Low
levels occured on 05 and 10 December with isolated C-class flare
activity observed from Region 2615 (S07, L=139, class/area Dai/200
on 05 Dec).

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
high levels on 05-07 December and on 09-11 December with moderate
levels observed on 08 December. A peak flux of 24,002 pfu was
observed at 11/1525 UTC.

Geomagnetic field activity ranged from quiet to active levels with a
couple of isolated G1 (Minor) storms periods. The period began with
quiet to isolated unsettled activity through midday on 07 December.
Solar wind parameters were nominal with winds speeds in the 300-375
km/s range. By midday to late on 07 December, activity levels
increased to unsettled to active as the field came under the
influence of a large, recurrent, negative polarity CH HSS. Phi angle
rotated from a positve to a negative orientation, wind speeds spiked
from about 375 km/s to near 550 km/s, total field Bt increased to 16
nT while the Bz component was variable between +14 nT to -8 nT. From
08-09 December, wind speeds continued to increase reaching a peak of
731 km/s early on 09 December. Field conditions responded with
unsettled to active levels with G1 (Minor) strom levels recorded
late on the 9th. From 10-11 December, field conditions were
generally at unsettled to active levels with some quiet periods on
the 10th. Wind speeds began a gradual decline with values near 550
km/s by the end of the summary period.

Forecast of Solar and Geomagnetic Activity
12 December - 07 January 2017

Solar activity is expected to be at very low levels with a slight
chance of C-class 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 be at mostly high levels through the summary period with
moderate levels likely on 19-21 December.

Geomagnetic field activity is expected to be at unsettled to active
levels on 18-25 December and again on 02-07 January due to recurrent
CH HSSs. In addition, G1 (Minor) storm conditions are likely on 21
December and 04-05 January to include G2 (Moderate) storm conditions
on 22 December. Mostly quiet conditions are expected for the
remainder of the outlook period.