Product: Weekly Highlights and Forecasts
:Issued: 2017 Aug 28 0402 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/weekly.html
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 21 - 27 August 2017
Solar activity ranged from very low to low levels. Very low levels were observed on 26 Aug while low levels were observed from 21-25 Aug and again on 27 Aug. Regions 2671 (N11, L=305, class/area Fkc/430 on 21 Aug) and 2672 (N08, L=227, class/area Dao/270 on 22 Aug) were the only regions on the visible disk and were responsible for a total of 34 C-class flares between the two. The largest events of the period were a C6/1f at 27/1516 UTC from Region 2671, a C5/Sf at 21/0316 UTC from Region 2672, and another C5/1n at 25/0727 UTC with an associated 100 sfu Tenflare from Region 2672. No Earth-directed coronal mass ejections (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 22-27 Aug while very high levels were observed on 21 Aug. The largest flux of the period was 52,010 pfu observed at 21/1725 UTC.
Geomagnetic field activity ranged from quiet to G2 (Moderate) storm levels. The period began under the waning influence of a positive polarity coronal hole high speed stream (CH HSS). Solar wind speed was decreasing from approximately 700 km/s to around 580 km/s by late on 21 Aug with total field values near 4 nT. By approximately 21/2100 UTC, total field began to increase to 9 nT while the Bz component deflected southward briefly to -8 nT. Solar wind speed increased once again to near 675 km/s at 22/0655 UTC before slowly decreasing once more. A prolonged period of southward Bz was observed between 22/1840-24/1310 UTC reaching a maximum of -6 nT.
The geomagnetic field responded with quiet to unsettled levels on 21 Aug, quiet to G2 (Moderate) geomagnetic storm levels on 22 Aug, and unsettled to G1 (Minor) geomagnetic storm levels on 23 Aug. Solar wind speed continued to decline to around 330 km/s by early on 25 Aug. Another enhancement in total field was observed at the end of the period to 10 nT with another prolonged period of southward Bz after 27/1200 UTC. The geomagnetic field responded with quiet to
unsettled conditions on 24 and 27 Aug while quiet conditions were observed on 25-26 Aug.
Forecast of Solar and Geomagnetic Activity 28 August - 23 September 2017
Solar activity is expected to be at very low to low levels throughout the forecast period. There is a slight chance for M-class (R1-R2, Minor-Moderate) flares from 28 Aug-02 Sep as Region 2672
transits across the visible disk.
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 throughout the forecast period due to recurrent CH HSS influence. A decrease to moderate levels is
expected on 30-31 Aug, 08 Sep, and again on 13 Sep due to electron redistribution associated with the arrival of the CH HSSs.
Geomagnetic field activity is expected to be at unsettled to active levels on 28 Aug, 30 Aug-02 Sep, 08-09 Sep, 13-17 Sep, and 23 Sep with G1 (Minor) geomagnetic storm levels likely on 31 Aug and 13-16 Sep and G2 (Moderate) geomagnetic storm levels likely on 14-15 Sep due to recurrent CH HSS activity.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2017 Aug 28 0402 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/wwire.html
#
# 27-day Space Weather Outlook Table
# Issued 2017-08-28
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2017 Aug 28 78 10 3
2017 Aug 29 78 8 3
2017 Aug 30 78 15 4
2017 Aug 31 77 25 5
2017 Sep 01 75 18 4
2017 Sep 02 74 15 3
2017 Sep 03 74 8 3
2017 Sep 04 72 5 2
2017 Sep 05 72 5 2
2017 Sep 06 72 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 6
2017 Sep 15 88 30 6
2017 Sep 16 88 25 5
2017 Sep 17 88 12 4
2017 Sep 18 88 8 3
2017 Sep 19 85 8 3
2017 Sep 20 85 5 2
2017 Sep 21 82 5 2
2017 Sep 22 80 5 2
2017 Sep 23 78 10 3
(NOAA)
