Astroblog: Aurora Watch and Geomagnetic Warning (25-27 October)

Tuesday, October 25, 2016

Aurora Watch and Geomagnetic Warning (25-27 October)

The Australian Space Weather Service (SWS ) has issued an Aurora Watch and a geomagnetic Warning for 25 - 27 October UT from a high speed solar wind stream from a large coronal hole.

Evening skies are Moon free, but cloud is problematic. The waning moon rises early in the morning. It is possible aurora may be seen in Tasmania and Victoria if storms eventuate.

Current conditions in Australia are marginal (Velocity: 431 km/sec Bz: -8.0 nT Density = 28.0 p/cc with Kindex of 3), although if the solar speed and density picks up the strong negative field is promising. G2 storm conditions have been predicted and the planetary Kindex is 5, However, conditions are expected to fluctuate rapidly through the evening so be on the lookout if cloud clears. At this stage it seems more likely that geomagnetic storms will occur early morning on the 26th.

Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported consistently over the last few aurora and a large green "blob" has been seen, as well as bright proton arcs and "picket fences".

Here is the near-real time satellite view of the clouds http://satview.bom.gov.au/
Cloud cover predictions can be found at SkippySky.

The all sky aurora camera in Northern Tasmania at Cressy is being upgraded and is not yet online.

SUBJ: SWS GEOMAGNETIC DISTURBANCE WARNING 16/42
ISSUED AT 2336UT/24 OCTOBER 2016
BY THE AUSTRALIAN SPACE FORECAST CENTRE.

Expect the geomagnetic activity to increase over the next three
days due to an increase in the solar wind speed associated with
a large coronal hole. Activity will very between Unsettled and
Major Storm conditions during this period.

INCREASED GEOMAGNETIC ACTIVITY EXPECTED
DUE TO CORONAL HOLE HIGH SPEED WIND STREAM
FROM 25-27 OCTOBER 2016
_____________________________________________________________

GEOMAGNETIC ACTIVITY FORECAST
25 Oct: Unsettled to Major Storm
26 Oct: Unsettled to Major Storm
27 Oct: Unsettled to Major Storm
===================================================================
SUBJ: SWS AURORA WATCH
ISSUED AT 2348 UT ON 24 Oct 2016 by Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE

A large positive polarity coronal hole extending from the solar north
pole across the equatorial region into the southern hemisphere of the
Sun will likely become geoeffective tonight, resulting in an increase
in geomagnetic activity. There is a possibility of visible auroras
during local nighttime hours. Aurora alerts will follow should
favourable space weather activity eventuate.

Further monitoring at
http://www.ips.gov.au

Labels: aurora