:Product: Weekly Highlights and Forecasts
:Issued: 2016 Jan 25 0701 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
18 - 24 January 2016

Solar activity was at very low to low levels during the period. Only
weak C-class flares (<C3) were observed on 20-21 January and 24
January from Regions 2484 (N08, L=094, class/area Dro/030 on 20
January), 2487 (S13, L=336, class/area Dai/100 on 21 January), and
2488 (N04, L=319, class/area Dai/200 on 24 January). Region 2487 was
in a growth phase since its emergence on 18 January, but entered
into a decay phase after 22 January and was only responsible for
three weak C-class flares. Region 2488 continued to exhibit growth
since its emergence on the disk on 18 January and was responsible
for two weak C-class flares. No Earth-directed coronal mass
ejections (CMEs) were observed during the summary period.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
normal levels on 19-20 January, moderate levels on 21 January and
high levels on 18 January and again on 22-24 January. The maximum
flux of the period was 12,881 pfu observed at 24/1550 UTC.

Geomagnetic field activity ranged from quiet to major storm
(G2-Moderate) levels. The period began under quiet conditions for
the majority of 18 January. At approximately 18/2056 UTC, a small
shock was observed in ACE data indicating the arrival of a CME from
a filament eruption on 14 January. Total field (Bt) initially
increased from 6 nT to 12 nT with solar wind speed increasing from
300 km/s to near 380 km/s while the Bz component fluctuated between
+6 nT and -9 nT. By 19/0935 UTC, the Bz component deflected north
and total field increased to 14 nT. A subsequent rotation of the Bz
component occurred after 20/0325 UTC to a maximum of -13 nT followed
by another increase in the total field to a maximum of 21 nT at
21/0545 UTC. By this time, the Bz component was fluctuating between
+/-18 nT. By 21/1006 UTC, Bt decreased to around 8 nT, while the
solar wind speed increased to around 530 km/s as the solar wind
began to transition into a negative polarity coronal hole high speed
stream (CH HSS). The geomagnetic field responded with an unsettled
period late on 18 January, quiet to active levels on 19 January,
quiet to minor storm levels (G1-Minor) on 20 January, and unsettled
to major storm levels (G2-Moderate) on 21 January. Solar wind speeds
continued around 500-550 km/s under CH HSS influence until late on
23 January. Solar wind speeds continued to be elevated in the
450-500 km/s range through the end of the period. As a result, the
geomagnetic field was at quiet to active periods from 22-24 January.

Forecast of Solar and Geomagnetic Activity
25 January - 20 February 2016

Solar activity is expected to be at very low to low levels with a
slight chance for an M-class flare (R1-R2, Minor-Moderate) from
25-31 January as Region 2488 continues to develop.

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 due to recurrent CH HSS
activity. A return to moderate levels is expected on 25-26 January,
07-08 February, and 14-18 February.

Geomagnetic field activity is expected to be at unsettled to active
levels from 25-30 January, 02-03 February, 07-10 February, and 17-20
February due to recurrent CH HSS activity.