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Tuesday, September 23, 2014

Weekly Propagation Forecast Bulletins




Product: Weekly Highlights and Forecasts
:Issued: 2014 Sep 22 0605 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 15 - 21 September 2014

Solar activity ranged from low to moderate levels during the period. Low levels were reached on 15-17 September and again on 19-21 September with moderate activity observed on 18 September. A
majority of the early C-class activity was observed from Regions 2158 (N16, L=087, class/area Dkc/440 on 11 Sep) and 2164 (S14, L=049, class/area Dai/090 on 14 Sep). The largest of these C-class events was a C7 X-ray event observed at 17/1948 UTC from Region 2158. 

By 18 September, activity increased to moderate levels. At 18/0709 UTC, Region 2169 (N05, L=290, class/area Cso/060 on 17 Sep) produced a C6/Sf which was immediately followed by an impulsive M1/Sn (R1-Minor) at 18/0841 UTC from the same region. Associated with this event were lower frequency radio emissions in the form of a Type II sweep and 245 MHz burst (16,000 sfu). An associated CME was not discernable in LASCO or STEREO imagery with the M1 event. 

19-21 September saw a return to low levels with C-class activity observed from Regions 2164, 2166 (N13, L=352, class/area Dao/060 on 14 Sep), 2171 (S10, L=264, class/area Eai/160 on 21 Sep) and 2172 (S11, L=242, class/area Ekc/320 on 21 Sep). The largest event during this 3-day period was a long-duration C5/1f flare at 21/1153 UTC from Region 2166. This region had decayed to plage on 20 September. Associated with this event was a CME off the NW limb, detected by LASCO C2 imagery, first visible at 21/1236 UTC. Potential geo-effectiveness of this CME was ongoing at the time of this writing. 

Other activity of note during the period was a N-S oriented, 38 degree long filament eruption along a channel centered near N25E12. The filament was observed lifting off in SDO/AIA 304 imagery from
20/2348-21/0427 UTC. No discernable CME was apparent in LASCO or STEREO imagery with the filament eruption. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was normal levels. 

Geomagnetic field activity ranged from quiet to minor storm levels. Mostly quiet levels were observed from 15 September through late on 18 September. By 18/1800 UTC, field activity increased to unsettled levels for six hours and further increased to active to minor storming through 21/0900 UTC. The field relaxed to unsettled to active levels through 21/2100 UTC when it became predominately quiet through the balance of the summary period. This period of increased
activity was attributed to a combination of transient and negative coronal hole high speed stream (CH HSS) effects. 

During the summary period, solar wind parameters, as observed at the ACE spacecraft, reflected the geomagnetic activity described above. ACE wind speeds began the period in the 450 km/s range and gradually decreased to near 350 km/s through early on 19 September. Wind speeds then increased to about 500 km/s by late on the 19th and further increased to 550 km/s by midday on 20 September and remained elevated through midday on the 21st. Speeds then declined to end the summary period near 425 km/s. 

The interplanetary magnetic field (IMF) Bt and Bz component followed a similar trend. Bt varied weakly from 3-7 nT through about 19/0600 UTC when an increase to 10-18 nT was observed for the next 9 hours or so. Bt gradually relaxed to vary between 4-8 nT through the remainder of the period. The Bz component generally did not vary much beyond -5 to +8 nT through the summary period. The exception was a period between 19/0400-1700 UTC when Bz varied between -13 nT to +17 nT. 

Phi angle measurements indicated a predominately negative (towards) orientation with positive (away) swings from about 18/1800 UTC - 19/1700 UTC and again from 21/0300 UTC - 21/1700 UTC. 

Forecast of Solar and Geomagnetic Activity 22 September - 18 October 2014

Solar activity is expected to be at predominately low levels with a chance for M-class activity and a slight chance for X-class activity through the outlook period. Regions currently on the disk with the
potential for major activity include Regions 2171 and 2172. Old Regions 2155 (S19, L=110), 2157 (S15, L=099) and 2158 (N16, L=089), producers of M and X-class activity on their previous transit, are all due to return on or about 28-29 September. 

No proton events are expected at geosynchronous orbit in the absence of major solar activity. 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be normal to moderate levels through 25 September. Moderate to high levels are expected from 26 September to 03 October
followed by a return to mostly normal levels through 18 October. 

Geomagnetic field activity is expected to be at predominately quiet levels through the outlook period. Quiet to unsettled levels are expected on 23-24 September due to a solar sector boundary crossing
followed by a co-rotating interaction region. Activity levels are expected to increase to unsettled to active from 25-30 September due to a series of positive polaritiy, equatorial CH HSSs. Unsettled to
active levels are expected on 15-17 October due to a negative polarity CH HSS. 



Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2014 Sep 22 0606 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 2014-09-22
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2014 Sep 22     125           5          2
2014 Sep 23     125           8          3
2014 Sep 24     130           8          3
2014 Sep 25     130          12          4
2014 Sep 26     130          15          4
2014 Sep 27     135          15          4
2014 Sep 28     140          10          3
2014 Sep 29     145           8          3
2014 Sep 30     150           8          3
2014 Oct 01     150           5          2
2014 Oct 02     150           5          2
2014 Oct 03     155           5          2
2014 Oct 04     155           5          2
2014 Oct 05     150           5          2
2014 Oct 06     150           5          2
2014 Oct 07     150           5          2
2014 Oct 08     145           5          2
2014 Oct 09     145           5          2
2014 Oct 10     140           5          2
2014 Oct 11     140           5          2
2014 Oct 12     135           5          2
2014 Oct 13     130           5          2
2014 Oct 14     125           5          2
2014 Oct 15     125           8          3
2014 Oct 16     120          15          4
2014 Oct 17     120           8          3
2014 Oct 18     120           5          2
(NOAA)