Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 May 2019

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 138 Issued at 2200Z on 18 May 2019

IA.  Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at very low levels for the past 24 hours. There is currently 1 numbered sunspot region on the disk.

IB.  Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (19 May, 20 May, 21 May).

IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 455 km/s at 18/0802Z. Total IMF reached 7 nT at 18/0609Z. The maximum southward component of Bz reached -4 nT at 18/0757Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 468 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (19 May) and quiet to unsettled levels on days two and three (20 May, 21 May).

III.  Event probabilities 19 May-21 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           18 May 071
Predicted   19 May-21 May 070/068/068
90 Day Mean        18 May 072

V.  Geomagnetic A Indices
Observed Afr/Ap 17 May  007/005
Estimated Afr/Ap 18 May  005/006
Predicted Afr/Ap 19 May-21 May  006/005-007/008-008/008

VI.  Geomagnetic Activity Probabilities 19 May-21 May
A.  Middle Latitudes
Active                10/25/25
Minor Storm           01/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/20/20
Minor Storm           20/30/30
Major-severe storm    15/25/25