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Monday, August 19, 2013

Weekly Propagation Forecast Bulletins



Product: Weekly Highlights and Forecasts
:Issued: 2013 Aug 19 0357 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 12 - 18 August 2013

Solar activity was moderate. The week began at moderate levels with Region 1817 (S21, L=241 class/area Ekc/260 on 15 Aug) producing an M1/Sn event at 12/1041 UTC. Activity was at low levels from 13 - 16 Aug with the largest event being a C4 at 14/0031 UTC from Region 1809 (N13, L=339). A Type II radio sweep (est. speed 1019 km/s) was observed on 15 Aug associated with a C2/Sf at 15/2216 UTC from Region 1817. There was an associated coronal mass ejection (CME) but it was determined to be directed well south of the ecliptic plane. Acitivty increased to moderate levels on 17 Aug with a pair of M flares from Region 1818 (S07, L=216 class/area Dki/330 on 16 Aug).
The first event was an impulsive M3/2b at 17/1824 UTC with associated weak, multi-frequency radio emissions. Immediately following the M3, Region 1818 produced an M1 x-ray event at 17/1933 UTC, again associated with weak, multi-frequency radio emissions including a 150 sfu Tenflare, a Type II radio sweep (est. speed 1399 km/s) observed in the lower spectral range and a broader spectral range Type IV radio sweep. An associated partial-halo CME was observed off the southwest limb and is expected to be a glancing blow at Earth on 21 Aug. 

The greater than 10 MeV proton flux at geosynchronous orbit was slightly elevated following the M-flare activity on 17 Aug but remained well below alert threshold. 

The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels from 12 - 15 Aug followed by an increase to moderate to high levels from 16 - 18 Aug due to effects from a coronal hole high speed stream (CH HSS). 

Geomagnetic field activity was at mostly quiet levels to begin the period on 12 Aug. Activity increased to unsettled to active conditions on 13 Aug due to the onset of a geo effective CH HSS. Although the CH HSS was still apparent on 14 Aug, quiet to unsettled conditions were predominate. A return to unsettled to active conditions returned on 15 - 16 Aug due to continued CH HSS effects, with an isolated minor storm period observed during the 0300 - 0600 UTC synoptic period due to nighttime sub-storming. Mostly quiet conditions were observed on 17 - 18 Aug as CH HSS effects subsided. 

Forecast of Solar and Geomagnetic Activity 19 August - 14 September 2013

Solar activity is expected to be at low levels with a chance for M-class activity from 19 - 21 Aug, mainly from Region 1818. Predominately low levels are expected from 22 Aug until the return of Regions 1817 and 1818 around 02 Sep, at which time the chance for M-class activity will return for the remainder of the period. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at moderate to high levels from 19 - 28 Aug due to CH HSS effects. A decrease to normal to moderate levels is expected from 29 Aug - 02 Sep as CH HSS effects subside followed by an increase to moderate to high levels from 03 - 08 Sep due to the effects of another CH HSS. Normal to moderate levels are expected from 09 - 12 Sep. Moderate to high levels are expected to prevail for the remainder of the period following the arrival of another recurrent CH HSS. 

Geomagnetic field activity is expected to be quiet to unsettled from 19 Aug until late 20 Aug followed by unsettled to active conditions as a recurrent, equatorial, positive CH HSS moves into a geoeffective position. Unsettled to active conditions with a slight chance for isolated minor storm periods are expected on 21 Aug due to continued CH HSS effects coupled with possible CME effects from the 17 Aug event. Quiet to unsettled conditions are expected on 22 Aug as CH HSS and CME effects wane. Predominately quiet conditions are expected from 23 - 30 Aug. A second CH HSS is expected to become geoeffective on 31 Aug, bringing activity up to quiet to unsettled levels until 02 Sep. Quiet conditions are expected to return 03 - 04 Sep followed by another small CH HSS that is expected to generate some isolated unsettled periods from 05 - 06 Sep. Quiet to active levels with a chance for isolated minor storm periods are expected for the remainder of the period due to the arrival of another recurrent CH HSS with a history of more intense geomagnetic effects. 



Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2013 Aug 19 0358 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 2013-08-19
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2013 Aug 19     130           5          2
2013 Aug 20     125          15          4
2013 Aug 21     120          22          4
2013 Aug 22     115          12          4
2013 Aug 23     110           8          3
2013 Aug 24     105           5          2
2013 Aug 25     105           5          2
2013 Aug 26     105           5          2
2013 Aug 27     105           5          2
2013 Aug 28     100           5          2
2013 Aug 29     100           5          2
2013 Aug 30     100           5          2
2013 Aug 31      95          12          3
2013 Sep 01      95          15          4
2013 Sep 02     100          10          3
2013 Sep 03     105           5          2
2013 Sep 04     105           5          2
2013 Sep 05     110           8          3
2013 Sep 06     110           5          2
2013 Sep 07     110           5          2
2013 Sep 08     110           5          2
2013 Sep 09     115           5          2
2013 Sep 10     115          10          3
2013 Sep 11     115          15          4
2013 Sep 12     120          18          4
2013 Sep 13     120           8          3
2013 Sep 14     125           8          3
(NOAA)