From the NOAA Space Weather Prediction Center, word that our recent X-class (and lesser magnitude) solar flares have released three Coronal Mass Ejections (CME’s) toward Earth:
The calm before the storm. Three CMEs are enroute, all a part of the Radio Blackout events on February 13, 14, and 15 (UTC). The last of the three seems to be the fastest and may catch both of the forerunners about mid to late day tomorrow, February 17. Watch this space for updates on the impending — G2, possibly periods of G3 — geomagnetic storming.
From Today’s Space Weather :
Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled on day one (16 February). Day two (17 February) is expected to be quiet to active with a chance for minor storming late in the period. Day three (18 February) is expected to be unsettled to active with a chance for minor storming. The increase in activity is forecast due to expected arrival of the CME from the X2 event described in part IA.
Aurora watchers can keep a lookout using this display:
This plot shows the current extent and position of the auroral oval in the northern hemisphere, extrapolated from measurements taken during the most recent polar pass of the NOAA POES satellite.
The red arrow in the plot, that looks like a clock hand, points toward the noon meridian.
The statistical pattern depicting the auroral oval is appropriate to the auroral activity level determined from the power flux observed during the most recent polar satellite pass. The power fluxes in the statistical pattern are color coded on a scale from 0 to 10 ergs .cm-2.sec-1 according to the color bar on the right. The pattern has been oriented with respect to the underlying geographic map using the current universal time, updated every ten minutes.
This presentation provides an estimate of the location, extent, and intensity of aurora on a global basis. For example, the presentation gives a guide to the possibility that the aurora is located near a given location in the northern hemisphere under the conditions that existed at the time of the most recent polar satellite pass.
Normalization factor (n)
A normalization factor of less than 2.0 indicates a reasonable level of confidence in the estimate of power. The more the value of n exceeds 2.0, the less confidence should be placed in the estimate of hemispheric power and the activity level.
The process to estimate the hemispheric power, and the level of auroral activity, involves using this normalization factor which takes into account how effective the satellite was in sampling the aurora during its transit over the polar region. A large (> 2.0) normalization factor indicates that the transit through the aurora was not very effective and the resulting estimate of auroral activity has a lower confidence. In order for users to assess the confidence in a given estimate of auroral power, we now report the numerical value of the normalization factor in our web pages.