:Product: Weekly Highlights and Forecasts
:Issued: 2016 Jul 18 0416 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
11 - 17 July 2016

Solar activity was at very low levels from 11-14 July with only a
few simple sunspot regions. Region 2565 (N05, L=175, class/area
Cko/350 on 17 Jul) rotated onto the east limb on 11 July as a simple
Hsx spot class with a simple alpha magnetic class. By late on 14
July, another spot group began to emerge behind Region 2565 and was
numbered 2567 (N05, L=165, class/area Dhi/330 on 17 Jul). Region
2567 quickly grew to over 300 millionths in area and was initially
classified as a beta-gamma-delta magnetic group before some magnetic
simplification occurred on 16 July. The region was downgraded to a
beta-gamma magnetic class for the remainder of the period. Region
2567 became the most active region during 15-17 July producing 13
C-class flares. However, the close proximity of the two regions, as
well as an active inversion line between the two, resulted in
several flares to be attributed to Region 2565 on 17 July. The first
was a long duration C1/Sf flare at 17/0803 UTC which was responsible
for two CMEs observed in SOHO/LASCO C2 imagery beginning at 17/1124
UTC and 17/1248 UTC. The first was a faint asymmetric halo CME while
the second was directed mostly off the east limb. Initial WSA-Enlil
model output of the events showed a slow transit with effects
possible on 21 July. The largest flare of the period, however, was a
C6 at 17/2335 UTC which also occurred on the inversion line and was
subsequently attributed to Region 2565.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels throughout the period with a maximum flux of 5,512 pfu
observed at 17/1630 UTC.

Geomagnetic field activity ranged from quiet to G1 (Minor) storm
levels. The majority of the period was under the influence of high
speed solar wind streams from a large, positive polarity, polar
connected coronal hole as well as an isolated, positive polarity
coronal hole. Solar wind speeds reached highs around 550 km/s early
on 11 July, 650 km/s late on 12 July, and 700 km/s early on 15 July
before finally decreasing to around 440 km/s by the end of the
period. Total field during the period only managed to reach a
maximum of 9 nT at 12/0552 UTC. Prolonged periods of southward Bz
reaching -8 nT on 12 July and -6 nT on 14 July resulted in periods
of G1 (Minor) storm levels on 12 July and active periods on 14 July.
The rest of the period was at quiet to unsettled levels with quiet
conditions observed on 17 July.

Forecast of Solar and Geomagnetic Activity
18 July - 13 August 2016

Solar activity is expected to be at low levels with a chance for
M-class (R1-R2, Minor-Moderate) flares from 18-24 July as Regions
2565 and 2567 transit across the visible disk. Very low levels are
expected for 25 Juy-04 August. A return to low levels with a chance
for M-class flaring is expected for 05-13 August with the return of
Regions 2565 and 2567.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at high levels on 18-19, 23-27 July, and again on
05-13 August due to recurrent CH HSS activity. Normal to moderate
levels are expected for the remaining forecast period.

Geomagnetic field activity is expected to be at unsettled to active
levels on 19-20, 22-24, 28, 30 July and on 03-08, 10-11 August with
G1 (Minor) storm levels likely on 03-04 and 08 August due to
recurrent CH HSS activity. A CME associated with the 17 July
long-duration C1 flare is likely to arrive early on 21 July causing
unsettled to active levels.