Monday, August 28, 2017

Weekly Propagation Forecast Bulletins


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)