Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 19 May 2017

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 139 Issued at 2200Z on 19 May 2017

IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: 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 slight chance for a C-class flare on days one, two, and three (20 May, 21 May, 22 May).

IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 603 km/s at 19/2100Z. Total IMF reached 13 nT at 19/0336Z. The maximum southward component of Bz reached -7 nT at 19/1814Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 329 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (20 May) and quiet to active levels on days two and three (21 May, 22 May).

III. Event probabilities 20 May-22 May
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 19 May 072
Predicted 20 May-22 May 072/072/074
90 Day Mean 19 May 077

V. Geomagnetic A Indices
Observed Afr/Ap 18 May 015/013
Estimated Afr/Ap 19 May 015/022
Predicted Afr/Ap 20 May-22 May 024/030-016/020-011/012

VI. Geomagnetic Activity Probabilities 20 May-22 May
A. Middle Latitudes
Active 40/20/20
Minor Storm 20/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/15/15
Major-severe storm 15/10/05