Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 February 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 51 Issued at 2200Z on 20 Feb 2017

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 2 numbered sunspot regions on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one, two, and three (21 Feb, 22 Feb, 23 Feb).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 563 km/s at 19/2234Z. Total IMF reached 5 nT at 20/1427Z. The maximum southward component of Bz reached -3 nT at 20/0238Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1049 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (21 Feb), quiet to active levels on day two (22 Feb) and unsettled to minor storm levels on day three (23 Feb).

III.  Event probabilities 21 Feb-23 Feb
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 Feb 081
Predicted   21 Feb-23 Feb 081/081/081
90 Day Mean        20 Feb 077

V.  Geomagnetic A Indices
Observed Afr/Ap 19 Feb  009/009
Estimated Afr/Ap 20 Feb  010/011
Predicted Afr/Ap 21 Feb-23 Feb  010/010-012/016-016/020

VI.  Geomagnetic Activity Probabilities 21 Feb-23 Feb
A.  Middle Latitudes
Active                20/30/40
Minor Storm           05/15/25
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/15/10
Minor Storm           30/30/25
Major-severe storm    30/40/60