:Product: Weekly Highlights and Forecasts
:Issued: 2017 Aug 21 0435 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 14 - 20 August 2017
Solar activity ranged from very low levels
to moderate levels over
the period. Very low levels were observed on 16-17
Aug, low levels
were observed on 14-15 Aug and again from 18-19 Aug, while
moderate
levels were observed on 20 Aug.
The period began with Region
2671 (N11, L=305, class/area Fkc/410 on
18 Aug) rotating around the east
limb. The region was in a growth
phase through 18 Aug and rapidly developed
from a simple Hax/alpha
spot group to an Fkc/beta-gamma group by 17 Aug with
an extent
reaching 20 heliographic degrees by 20 Aug. Although a
magnetically
complex spot group, it only managed 11 C-class flares. The
largest
was a C7/Sf, with an associated Type II (928 km/s) radio sweep,
at
19/2155 UTC. Although coronal dimming was observed in SDO/AIA
193
imagery beginning at 19/2143 UTC, there was no observable
indications
of an associated coronal mass ejection (CME) in
coronagraph imagery. Another
region began producing C-class activity
on the east limb beginning on 18 Aug.
By 20 Aug, the region rotated
into view and was numbered 2672 (N05, L=225,
class/area Dao/beta on
20 Aug). This region produced an M1 flare (R1-Minor)
at 20/0152 UTC.
No Earth-directed CMEs were observed during the period.
No proton events were observed at geosynchronous orbit.
The
greater than 2 MeV electron flux at geosynchronous orbit reached
high levels
from 14-16 Aug and again from 18-20 Aug. A decrease to
moderate levels was
observed on 17 Aug coinciding with the arrival
of a positive polarity coronal
hole high speed stream (CH HSS). The
largest flux value of the period was
23,392 pfu observed at 20/1540
UTC.
Geomagnetic field activity ranged
from quiet to G1 (Minor)
geomagnetic storm levels. The period began under the
waning
influence of a negative polarity CH HSS. Solar wind speed
decreased
from near 600 km/s to around 360 km/s by 16 Aug while total
field
was between 3-5 nT. Early on 16 Aug, total field began to
increase
to a maximum of 13 nT at 17/0740 UTC while the solar wind
speed
slowly increased to around 780 km/s by late on 19 Aug as a
polar
connected, positive polarity CH HSS became geoeffective. By the
end
of the period, solar wind speeds decreased to near 650 km/s
while
total field values had decreased to 3 nT. The geomagnetic
field
responded with quiet levels from 14-16 Aug, followed by quiet to
G1
(Minor) storm levels from 17-20 Aug.
FORECAST OF SOLAR AND
GEOMAGNETIC ACTIVITY 21 AUGUST-16 SEPTEMBER 2017
Solar activity is
expected to be at low levels with a chance for
M-class (R1-R2,
Minor-Moderate) activity from Regions 2671 and 2672
from 21 Aug-02 Sep and
again from 08-16 Sep when both regions return
to the visible disk. Very low
levels are expected from 03-07 Sep.
No proton events are expected at
geosynchronous orbit.
The greater than 2 MeV electron flux at
geosynchronous orbit is
expected to reach high levels from 21-30 Aug, 01-07
Sep, 11-13 Sep,
and again from 15-16 Sep due to recurrent CH HSS influence.
Geomagnetic field activity is expected to be at unsettled to
active
levels from 21-22 Aug, 30 Aug-02 Sep, 08-09 Sep, and from 13-16
Sep
with G1 (Minor) storm levels likely on 31 Aug, and 13-16 Sep due
to
recurrent CH HSS activity.
:Product: 27-day Space Weather Outlook
Table 27DO.txt
:Issued: 2017 Aug 21 0435 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/wwire.html
#
#
27-day Space Weather Outlook Table
# Issued
2017-08-21
#
# UTC Radio Flux Planetary Largest
#
Date 10.7 cm A Index Kp Index
2017 Aug 21 90
18 4
2017 Aug 22 90 12 4
2017 Aug 23
90 8 3
2017 Aug 24 90 5 2
2017
Aug 25 90 5 2
2017 Aug 26 90
5 2
2017 Aug 27 85 5 2
2017 Aug 28
80 5 2
2017 Aug 29 78 5 2
2017
Aug 30 78 12 4
2017 Aug 31 78
24 5
2017 Sep 01 78 18 4
2017 Sep 02
78 14 4
2017 Sep 03 75 5 2
2017
Sep 04 75 5 2
2017 Sep 05 75
5 2
2017 Sep 06 75 5 2
2017 Sep 07
75 5 2
2017 Sep 08 80 10 3
2017
Sep 09 85 8 3
2017 Sep 10 85
5 2
2017 Sep 11 85 5 2
2017 Sep 12
85 5 2
2017 Sep 13 85 25 5
2017
Sep 14 85 30 5
2017 Sep 15 88
30 5
2017 Sep 16 88 25 5
(SWPC via
DXLD)
