Tuesday, September 02, 2014

Weekly Propagation Forecast Bulletins


Product: Weekly Highlights and Forecasts
:Issued: 2014 Sep 01 0657 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web www.swpc.noaa.gov/weekly.html
#
#                Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 25 - 31 August 2014

Solar activity was at low to moderate levels during the period. Moderate levels were observed on 25 August due to a pair of M-flares originating from Region 2146 (N07, L=344, class/area Dki/300 on 26 August). The first was a M2/1b flare at 25/1511 UTC with associated Type II (707 km/s) and Type IV radio sweeps, a Ten cm radio burst (150 sfu), and a coronal mass ejection (CME) primarily off the west
limb in SOHO/LASCO C2 imagery beginning at 25/1548 UTC. The second flare was an M3 at 25/2021 UTC which also had a CME off the west limb in SOHO/LASCO C2 imagery beginning at 25/2048 UTC. Both CMEs were determined to be directed too far west to be geoeffective. The rest of the period was populated with numerous low to mid-level C-class flares, the majority of which were from Regions 2146 and
2149 (N09, L=284, class/area Dkc/280 on 31 August). 

An enhancement of the greater than 10 MeV proton flux at geosynchronous orbit was observed beginning at approximately 25/2125 UTC likely associated with the M-class flares from Region 2146. A peak flux value of 1.4 pfu (below S1-Minor) was observed at 25/2300 UTC and thereafter gradually returned to background levels by 27 August. 

The greater than 2 MeV electron flux at geosynchronous orbit was at normal levels on 27 August, moderate levels on 25-26 August and again from 28-29 August. High levels were reached on 30-31 August with the flux of 1,510 pfu observed at 30/1550 UTC. 

Geomagnetic field activity started at quiet levels on 25-26 August. By early on 27 August, total field increased from 5 nT to a maximum of 15 nT by 27/0848 UTC, solar wind speed slowly increased, and the Bz component went south for the majority of the day reaching a maximum of -14 nT indicative of the arrival of a pair of CMEs that were associated with flare activity from Region 2146 on 22 August. Solar wind continued to slowly increase through 29 August when it became variable between approximately 380 km/s to 480 km/s. Phi angle became mostly positive (away) by late on 27 August and remained so during the rest of the period. This was indicative of a slow transition from CME activity into positive polarity coronal hole high speed streams (CH HSS) by mid to late on 28 August. The geomagnetic field responded with mostly quiet to active conditions from 27 August through 31 August with isolated minor storm periods observed on 28-29 August. Periods of major storm levels were observed at high latitudes on 27-28 August and again on 30-31 August with an isolated severe storm period observed on 29 August. 

Forecast of Solar and Geomagnetic Activity 01 September - 27 September 2014

Solar activity is expected to be at low levels with a slight chance for M-class (R1-R2, Minor-Moderate) flaring from 01-09 September. Beginning on 10 September and lasting through the end of the forecast period, M-class flare probabilities are expected to increase to a chance as old Regions 2146, 2149, and 2151 (S08,
L=253, class/area Cso/140 on 25 August) return to the visible disk. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 01-03, 07-09, and 27 September due to CH HSS influence. 

Geomagnetic field activity is expected to reach unsettled to active levels from 01-08, 13, and 25-27 September due to CH HSS activity as well as possible recurrent solar sector boundary crossings. 

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2014 Sep 01 0657 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 2014-09-01
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2014 Sep 01     130          12          4
2014 Sep 02     130           8          3
2014 Sep 03     125           8          3
2014 Sep 04     120          10          4
2014 Sep 05     115           8          3
2014 Sep 06     110          10          4
2014 Sep 07     105           8          3
2014 Sep 08     105          12          4
2014 Sep 09     105           5          2
2014 Sep 10     110           5          2
2014 Sep 11     115           5          2
2014 Sep 12     115           5          2
2014 Sep 13     115           8          3
2014 Sep 14     110           5          2
2014 Sep 15     110           5          2
2014 Sep 16     120           5          2
2014 Sep 17     130           5          2
2014 Sep 18     130           5          2
2014 Sep 19     130           5          2
2014 Sep 20     135           5          2
2014 Sep 21     135           5          2
2014 Sep 22     130           5          2
2014 Sep 23     125           5          2
2014 Sep 24     120           5          2
2014 Sep 25     115          12          4
2014 Sep 26     115          18          4
2014 Sep 27     125          15          4
(NOAA)