Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 May 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast

SDF Number 137 Issued at 2200Z on 17 May 2015

IA.  Analysis of Solar Active Regions and Activity from 16/2100Z to

17/2100Z: Solar activity has been at very low levels for the past 24

hours. There are currently 6 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 and a slight chance for an M-class

flare on days one and two (18 May, 19 May) and expected to be very low

with a chance for a C-class flares on day three (20 May).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic

field has been at quiet levels for the past 24 hours. Solar wind speed,

as measured by the ACE spacecraft, reached a peak speed of 428 km/s at

17/0716Z. Total IMF reached 8 nT at 17/2057Z. The maximum southward

component of Bz reached -5 nT at 17/1617Z. Electrons greater than 2 MeV

at geosynchronous orbit reached a peak level of 9241 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected

to be at quiet to active levels on days one and two (18 May, 19 May) and

quiet levels on day three (20 May).

III.  Event probabilities 18 May-20 May

Class M    10/10/01

Class X    01/01/01

Proton     01/01/01

PCAF       green

IV.  Penticton 10.7 cm Flux

Observed           17 May 120

Predicted   18 May-20 May 115/105/095

90 Day Mean        17 May 128

V.  Geomagnetic A Indices

Observed Afr/Ap 16 May  007/006

Estimated Afr/Ap 17 May  010/012

Predicted Afr/Ap 18 May-20 May  012/015-010/012-006/005

VI.  Geomagnetic Activity Probabilities 18 May-20 May

A.  Middle Latitudes

Active                30/25/10

Minor Storm           10/05/01

Major-severe storm    01/01/01

B.  High Latitudes

Active                15/15/20

Minor Storm           30/25/20

Major-severe storm    40/30/10