Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 31 May 2018

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 151 Issued at 2200Z on 31 May 2018

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to
31/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 1 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 (01 Jun,
02 Jun, 03 Jun).

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 498 km/s at 31/2100Z. Total IMF reached 17
nT at 31/1645Z. The maximum southward component of Bz reached -11 nT at
31/1705Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 579 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on days one and two (01 Jun, 02
Jun) and quiet to active levels on day three (03 Jun).

III. Event probabilities 01 Jun-03 Jun
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 31 May 077
Predicted 01 Jun-03 Jun 077/077/077
90 Day Mean 31 May 070

V. Geomagnetic A Indices
Observed Afr/Ap 30 May 005/004
Estimated Afr/Ap 31 May 011/014
Predicted Afr/Ap 01 Jun-03 Jun 018/025-019/025-011/015

VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun
A. Middle Latitudes
Active 35/35/30
Minor Storm 25/25/15
Major-severe storm 05/05/05
B. High Latitudes
Active 10/10/10
Minor Storm 25/25/25
Major-severe storm 55/55/45