|
Here is the current forecast discussion on space weather and geophysical activity, issued 2015 Mar 17 1440 UTC.
Solar Activity
24 hr Summary: Solar activity declined to low levels. Region 2297 was responsible for all the observed flares, the largest of which was a C8/1n at 16/2049 UTC. Intermediate spots in Region 2297 decayed, and some erosion of the trailer spot penumbra was observed. Some minor flux emergence was observed in the northwest quadrant.
A filament was observed lifting off the Southwest limb between 16/1500-16/1600 UTC, but based on source locations and apparent trajectory in SDO imagery, it is not expected to have an impact. No obvious Earth-directed CMEs were detected using SOHO/LASCO coronagraph imagery available through 16/2310 UTC.
Forecast: More M-class (R1-R2/Minor-Moderate) flares are likely from Region 2297, with a slight chance for an X-class (R3 or greater) flare, over the next three days (17-19 Mar).
Energetic Particle
24 hr Summary: The greater than 2 MeV electron flux was at normal levels throughout the period. The greater than 10 MeV proton flux remained enhanced, declining from a peak flux of 6.7 pfu at 16/1325 UTC to end near 1 pfu.
Forecast: The greater than 2 MeV electron flux is expected to be at normal to moderate levels over the next three days (17-19 Mar). The greater than 10 MeV proton flux levels are expected to exceed the S1 (Minor) solar radiation storm levels on day one (17 Mar) following the anticipated shock passage of the 15 Mar CME. There will still be a chance for elevated proton flux levels on days two and three (18-19 Mar), as CME effects subside.
Solar Wind
24 hr Summary: An interplanetary shock passed the ACE spacecraft at 17/0405 UTC. The subsequent sudden impulse was observed at Earth at 17/0445 UTC (54 nT at Boulder). Bt jumped to 27 nT from 10 nT with the shock arrival. Bz was initially positive, but then decreased to -22 nT by 17/0534 UTC. It continued to oscillate between negative and positive values, dipping as low as -23 nT at times. Solar wind speed had been steady near 400 km/s, then jumped to about 500 km/s with shock arrival. Wind speed then began to climb, reaching 600 km/s by 17/0800 UTC. Temperature also began to clime steadily in the wake of the shock while density fell. Initial diagnosis suggested the arrival of the anticipated CME from 15 Mar, however the subsequent temperature and density measurements pointed towards a recurrent negative polarity coronal hole high speed solar wind stream. Phi, although somewhat variable, was generally negative throughout the post-shock period. The disturbed conditions may be the combined effects of the high speed stream and CME.
Forecast: Disturbed solar wind conditions are expected to persist for the next three days (17-19 Mar).
Geospace
24 hr Summary: The geomagnetic field was at quiet to unsettled levels until the arrival of the sudden impulse at 17/0445 UTC. Conditions quickly reached active levels, minor storm (G1) levels by 17/0559 UTC, major storm (G2) by 17/0846 UTC and again at 17/1125 UTC, severe storm (G3) by 17/1330 UTC and severe storm (G4) by 17/1358 UTC .
Forecast: The remainder of 17 March is expected to see active (
Don't forget to visit our live space weather and radio propagation web site, at: http://SunSpotWatch.com/
Live Aurora mapping is at http://aurora.sunspotwatch.com/
If you are on Twitter, please follow these two users:
+ https://Twitter.com/NW7US
+ https://Twitter.com/hfradiospacewx
Get the space weather and radio propagation self-study course, today. Visit http://nw7us.us/swc for the latest sale and for more information!
We're on Facebook: http://NW7US.us/swhfr
![Today's Propagation Summary]()
|