Monday, April 14, 2014

Weekly Propagation Forecast Bulletins


Product: Weekly Highlights and Forecasts
:Issued: 2014 Apr 14 0224 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 07 - 13 April 2014

Solar activity was low. The largest flare of the week was a C9, with no optical counterpart, produced by Region 2035 (S18, L=222, class/area=Eai/210 on 13 Apr) on 11 Apr at 1124 UTC. The same region produced a C5 flare at 11/1501 UTC. A small CME, most likely associated with the C9 event, was visible in LASCO C2 coronagraph imagery at 11/1212 UTC but was directed well south and east of the ecliptic plane. A much larger CME associated with the C5 flare was observed in LASCO C2 imagery at 11/1448 UTC. The CME was also on the east limb and the majority of the ejecta was directed away from Earth. Region 2035 began as a plage area on 09 Apr and by the 11th had grown to a Dao Beta-type group with 2 spots. It developed a beta-gamma magnetic configuration on the 12th. 

In addition to CMEs associated with the week's largest flares, others accompanied filament eruptions. A 9 degree filament eruption was observed near S23E25 at 10/0004 UTC. An associated CME occurred off the southeast limb with an estimated speed of 298 km/s. Around the same time, Region 2031 (N03, L=30, class/area=Dao/50 on 08 April) produced a C1/Sf flare at 10/0013 UTC and a slow, westward-directed coronal mass ejection (CME) with coronal dimming visible in SDO/AIA imagery. Analysis suggested a speed near 330 km/s. A Type II radio sweep (1109 km/s) was also observed between 10/0010-0022 UTC . A 14 degree filament centered near S35W48 disappeared at 10/0622 UTC with no apparent CME in LASCO imagery. Neither these CMEs, nor others occurring throughout the week, were judged to be particularly geoeffective. 

No proton events were observed at geosynchronous orbit, however, the week began with slightly elevated flux levels (<1 pfu) in the wake of an M6 flare the previous week. By 09 April, flux had returned to background levels. 

The greater than 2 MeV electron flux at geosynchronous orbit was normal to moderate throughout the week. 

Geomagnetic field activity began the week at unsettled to active levels on 07 April attributed to the muted effects of transient features. Activity remained at quiet levels from 08 April through late on 11 April. Late on the 10th, around 1928 UTC, there was a modest increase in solar wind speed from 350-400 km/s. The brief episode of increased winds was followed by a jump in density and  accompanied by fluctuations in Phi angle. Over the next 36 hours, this exhibited a smooth rotation from a positive to a negative orientation. Bz began to plunge southward around 11/0940 UTC, reaching a minimum of about -10 nT by 12/0800 UTC. Bt reached a maximum near 12 nT by 12/1406 UTC. Throughout the 11th and 12th, solar wind speed continued to decline, reaching a minimum of 316 km/s at 12/1331 UTC. The planetary geomagnetic field responded to the nearly 24 hours of southward Bz with minor storm conditions (Kp=5) from 00-09 UTC on 12 April and a major storm period observed at College (Fairbanks), AK. The remainder of the 12th saw quiet to unsettled conditions. Late on the 12th, temperature and wind speed began to rise signaling the end of the transient feature and the beginning of the influence of a weak negative polarity cornal hole high speed stream.Active conditions returned for the first two synoptic periods of the13th followed by quiet to unsettled levels of activity. 

Forecast of Solar and Geomagnetic Activity 14 April - 10 May 2014

Solar activity is expected to be low with a chance for moderate events throughout the forecast period. There is a chance for high levels of activity on 25 April through 08 May with the return of Old Region 2027. 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels. 

Geomagnetic field activity is expected to be at quiet to unsettled levels, in the absence of any transient features, throughout the forecast period. 

Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2014 Apr 14 0224 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 2014-04-14
#
#   UTC      Radio Flux   Planetary   Largest
#  Date       10.7 cm      A Index    Kp Index
2014 Apr 14     140           8          3
2014 Apr 15     145           8          3
2014 Apr 16     145           5          2
2014 Apr 17     145           5          2
2014 Apr 18     145           5          2
2014 Apr 19     145           5          2
2014 Apr 20     145           5          2
2014 Apr 21     145           5          2
2014 Apr 22     145           5          2
2014 Apr 23     140           5          2
2014 Apr 24     140           5          2
2014 Apr 25     140           5          2
2014 Apr 26     140           5          2
2014 Apr 27     140           5          2
2014 Apr 28     130           5          2
2014 Apr 29     130           5          2
2014 Apr 30     125           5          2
2014 May 01     120           5          2
2014 May 02     120           5          2
2014 May 03     125           5          2
2014 May 04     125           5          2
2014 May 05     125           5          2
2014 May 06     130           5          2
2014 May 07     130           5          2
2014 May 08     130           5          2
2014 May 09     130           5          2
2014 May 10     130           5          2
(NOAA)