Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 May 2022

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 138 Issued at 2200Z on 18 May 2022

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4 event observed at 18/1549Z from Region 3014 (N21E17). There are currently 7 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare 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 to unsettled levels for the past 24 hours. Solar 17/2350Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 164 pfu.

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

III. Event probabilities 19 May-21 May
Class M 35/30/30
Class X 15/15/15
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 May 180
Predicted 19 May-21 May 180/180/178
90 Day Mean 18 May 122

V. Geomagnetic A Indices
Observed Afr/Ap 17 May 015/013
Estimated Afr/Ap 18 May 008/008
Predicted Afr/Ap 19 May-21 May 010/014-010/012-008/008

VI. Geomagnetic Activity Probabilities 19 May-21 May
A. Middle Latitudes
Active 30/30/25
Minor Storm 10/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/30/30
Major-severe storm 40/40/30