Monday, June 23, 2014

Weekly Propagation Forecast Bulletins

Product: Weekly Highlights and Forecasts
:Issued: 2014 Jun 23 0420 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
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#                Weekly Highlights and Forecasts
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Highlights of Solar and Geomagnetic Activity 16 - 22 June 2014

Solar activity was at low levels this period with only C-class flares observed. Region 2085 (S20, L=257, class/area=Ekc/490 on 12 Jun), which was very active last period, produced a long duration C8 flare from behind the west limb which was the largest event of the period. 

Among regions that were in transit across the visible disk this period, Regions 2087 (S18, L=155, class/area=Eac/220 on 13 Jun), 2089 (N18, L=197, class/area=Dkc/270 on 16 Jun), and 2093 (S12, L=083, class/area=Dso/70 on 16 Jun) were the most productive. 

Early in the period Regions 2087 and 2089 were the most active. Region 2087 produced seven C-class flares this period with a C4 flare at 17/0510 UTC being the largest. Region 2089 also produced seven C-class flares, the largest of which was a C2/Sf flare at 16/0734 UTC. Later in the period Region 2093 became the primary solar flare producer, totaling nine C-class flares with a C5/1n flare at 20/1120 UTC being the largest. 

On 19 Jun a large (~24 degree) and dynamic filament eruption centered near S01E12 lifted off between 1530-1655 UTC, as seen in SDO AIA/304 and 193 imagery. A subsequent partial halo coronal mass ejection (CME) off the east limb became visible in LASCO C2 coronagraph imagery beginning at 19/1924 UTC. Forecaster analysis and WSA-ENLIL model output suggested this CME had an Earth-directed
component with an estimated arrival predicted late in the period (UTC) on 22 Jun. 

Another filament eruption (~28 degree) centered near N26E09 was observed in SDO AIA/193 imagery lifting off between 0330-0600 UTC on 21 Jun. A subsequent CME was observed off the north-northwest limb in LASCO C2 in coronagraph imagery beginning at 21/0536 UTC. Analysis of this event indicated a possible glancing blow midday on 24 Jun. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal levels to begin the period (16-19 Jun) with an increase to normal to moderate levels later in the period (20-22 Jun). The 2 MeV electron flux reached a peak value of 487 pfu at 20/1440 UTC. 

Geomagnetic field activity was predominately at quiet to unsettled levels throughout the period with the exception of an isolated active period (18/1800-2100 UTC) and an isolated period of G1 (Minor) geomagnetic storm conditions (18/2100-2359 UTC) due to a negative polarity coronal hole high speed stream (CH HSS) and prolonged southward Bz. 

A G1 (Minor) geomagnetic storm watch was issued for 22 Jun for the anticipated arrival of the 19 Jun CME (detailed above), however, the transient did not arrive as predicted and G1 conditions were not observed on the 22nd. This is likely due in part to a minor deviation in one of the many variables that transient features
enounter during the 93-million mile journey to the Earth. 

Forecast of Solar and Geomagnetic Activity 23 June - 19 July 2014

Solar activity is expected to increase throughout the outlook period due to the return of a few active regions that were relatively productive last rotation. Solar activity is likely to be low with a slight chance for M-class (R1-R2 (Minor-Moderate)) flare activity for 23-25 Jun. As Regions 2080 (S11, L=263) and 2085 (S20, L=256) return to the visible disk, solar activity is expected to be low with a chance for M-class (R1-R2) flare activity for 26 Jun-05 Jul. Region 2080 produced two M-class flares and Region 2085 produced three M-class flares last rotation. Solar activity is likely to be moderate (R1-R2) with a chance for X-class (R3 or greater) flare activity for 06-11 Jul with the return of Region 2087 (S18, L=155) which produced eight M-class flares and three X-class flares last rotation. Solar activity is expected to be low with a chance for M-class (R1-R2) and a slight chance for X-class (R3 or greater) flare activity for 12-19 Jul as Regions 2080 and 2085 rotate around the west limb and Region 2087 continues its transit across the disk. 

There is a slight chance for S1 (Minor) solar radiation storm conditions for 06 Jun-19 Jul due to the return of old Region 2087 . 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal levels with a chance for moderate levels throughout the outlook period. 

Geomagnetic field activity is expected to be at quiet levels to G1 (Minor) geomagnetic storm conditions on 23 Jun due to the arrival of the 19 Jun coronal mass ejection (CME). Quiet to active levels are expected on 24-25 Jun as CME effects subside in conjunction with the onset of a negative polarity coronal hole high speed stream (CH HSS). Quiet to active levels are expected on 26 Jun due to continued negative polarity CH HSS influence. Predominately quiet conditions and a nominal solar wind environment are expected for 27 Jun-10 Jul, 12-13 Jul, and 18-19 Jul. Quiet to unsettled conditions are likely on 11 Jul due to weak positive polarity CH HSS effects. Quiet to unsettled conditions are expected on 14 Jul and 16-17 Jul with quiet to active conditions on 15 Jul due to influence from a negative polarity CH HSS. 
(NOAA)