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[Propagation+Space Weather] Today's Space Weather Forecast Discussion on

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Subject: [Propagation+Space Weather] Today's Space Weather Forecast Discussion on
From: nw7us@sunspotwatch.com
Reply-to: Practical radio-wave propagation and space weather <propagation@contesting.com>
Date: Thu, 12 Nov 2015 20:07:05 +0000
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Here is the current forecast discussion on space weather and geophysical activity, issued 2015 Nov 12 1230 UTC.

Solar Activity

24 hr Summary: Solar activity remained at very low levels. Region 2448 (N04W23, Hrx/alpha) continued to decay. Despite the unipolar classification and dissipating spots, the region underwent an enhancement observed in GOES-15/SXI imagery that began about 11/1400 UTC. The enhancement appeared related to a coronal disruption that began shortly afterwards as evident in SDO/AIA imagery. The disruption was associated with a coronal mass ejection (CME) from the W limb, first seen in SOHO/LASCO C2 imagery at 11/1524 UTC. Analysis indicated primarily a W to NW directed component to the ejection and no interaction with Earth is expected. Region 2449 (S12W02, Dro/beta) decayed further and was inactive. An active region just beyond the NE limb, as visible in SDO/AIA and GOES-15/SXI imagery, produced two B8 flares (the only flares of the period). The remaining regions were stable or in decay.

Another CME occurred from the SE limb, first visible in SOHO/LASCO C2 imagery at 11/2200 UTC. The CME appeared to emanate from the vicinity of now spotless Region 2452 (S08E36). Analysis indicated the CME to be off the Sun-Earth line. No Earth-directed coronal mass ejections were observed in available coronagraph imagery.

Forecast: Solar activity is expected to remain at low levels, with a slight chance for R1-R2 (Minor-Moderate) Radio Blackouts all three days (12-14 Nov) primarily due to minor instability in Region 2448. The slightly higher flare potential of Region 2449 and the active region of interest just beyond the NE limb are also contributors to the forecast.

Energetic Particle

24 hr Summary: The greater than 2 MeV electron flux reached very high levels with a peak flux of 59,508 pfu observed at 11/1915 UTC. The greater than 10 MeV proton flux remained at background levels.

Forecast: The greater than 2 MeV electron flux is expected to be at moderate to high levels over the next three days (12-14 Nov), with brief increases to very high levels on day one (12 Nov), due to effects from the coronal hole high speed stream (CH HSS). The greater than 10 MeV proton flux is expected to remain at background levels throughout the forecast period.

Solar Wind

24 hr Summary: Solar wind and interplanetary magnetic field (IMF) parameters, as measured by the ACE spacecraft, indicated waning conditions from a positive polarity coronal hole high speed stream (CH HSS). Solar wind velocities began the period between about 650-700 km/s until approximately 11/1900 UTC when solar wind speeds began a gradual decline, ending the period around 500 km/s. Total IMF strength (Bt) held between 2 to 5 nT. The Bz component began the period in primarily a southward orientation, becoming variable after 11/1852 UTC. The phi angle was predominantly positive (away) until 12/0645 UTC when it oscillated into a negative (towards) sector until it shifted back positive again at 12/1130 UTC.

Forecast: Solar wind speed is expected to continue in slow decline on day one (12 Nov) as the CH HSS effects wane. As of yet, the expected effects from the 9 Nov CME, have not materialized. It is unclear at this time whether the CME missed Earth or is traveling slower than expected and has yet to arrive. Day two (13 Nov) is likely to see a continued trend towards more ambient conditions until later in the day and on into day three (14 Nov), when an increase in solar wind speed and total magnetic field strength is likely due to effects from another positive polarity CH HSS.

Geospace

24 hr Summary: The geomagnetic field was primarily at quiet to unsettled levels, except for the 11/1500-1800 UTC synoptic period when activity reached G1 (Minor) storm levels. The minor storming was likely the result of enhanced solar wind speeds and a sustained period of southward Bz.

Forecast: G1 (Minor) storm conditions are still considered likely on day one (12 Nov) due to a possible late arrival of the 9 Nov CME. Day two (13 Nov) is expected to experience unsettled to active conditions as CH HSS and any possible transient influences wane. Day three (14 Nov) is expected to see increased activity, with a likely period of isolated G1 (Minor) storm levels, as the next positive polarity CH HSS interacts with Earths magnetosphere.

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Today's Space Weather Forecast Discussion - 2015 Nov 12 20:07 UTC

Live data: SunSpotWatch.com

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