Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 May 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 144 Issued at 2200Z on 24 May 2013

IA. Analysis of Solar Active Regions and Activity from 23/2100Z to
24/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C2 event observed at
24/0124Z. There are currently 5 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (25 May, 26 May,
27 May).

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 621 km/s at 24/2058Z. Total IMF reached 15 nT at 24/1739Z. The
maximum southward component of Bz reached -14 nT at 24/1738Z. Protons
greater than 10 MeV at geosynchronous orbit reached a peak level of 368
pfu at 23/2105Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 2063 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (25 May) and quiet to
unsettled levels on days two and three (26 May, 27 May). Protons are
likely to continue above threshold levels on day one (25 May), have a
chance of remaining above threshold on day two (26 May) and have a
slight chance of remaining above threshold on day three (27 May).

III. Event probabilities 25 May-27 May
Class M 25/25/25
Class X 01/01/01
Proton 60/30/10
PCAF yellow

IV. Penticton 10.7 cm Flux
Observed 24 May 127
Predicted 25 May-27 May 130/125/125
90 Day Mean 24 May 122

V. Geomagnetic A Indices
Observed Afr/Ap 23 May 008/008
Estimated Afr/Ap 24 May 014/019
Predicted Afr/Ap 25 May-27 May 014/022-008/012-007/008

VI. Geomagnetic Activity Probabilities 25 May-27 May
A. Middle Latitudes
Active 35/20/10
Minor Storm 20/05/01
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 30/25/20
Major-severe storm 55/25/20