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 web contact 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 September 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 web contact 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
(NOAA)