:Product: 0516RSGA.txt
:Issued: 2013 May 16 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 136 Issued at 2200Z on 16 May 2013

IA.  Analysis of Solar Active Regions and Activity from 15/2100Z to
16/2100Z: 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
16/1924Z from Region 1748 (N12E36). There are currently 10 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be high with
a chance for X-class flares on days one, two, and three (17 May, 18 May,
19 May).

IIA.  Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed, as measured by the ACE spacecraft, reached a peak speed of
450 km/s at 15/2326Z. Total IMF reached 7 nT at 15/2115Z. The maximum
southward component of Bz reached -6 nT at 16/0139Z. Protons greater
than 10 MeV at geosynchronous orbit reached a peak level of 32 pfu at
16/0410Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 117 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (17 May) and quiet to
unsettled levels on days two and three (18 May, 19 May). Protons are
expected to cross threshold on day one (17 May), are expected to cross
threshold on day two (18 May) and are expected to cross threshold on day
three (19 May).

III.  Event probabilities 17 May-19 May
Class M    75/75/75
Class X    50/50/50
Proton     99/95/90
PCAF       yellow

IV.  Penticton 10.7 cm Flux
Observed           16 May 145
Predicted   17 May-19 May 145/145/140
90 Day Mean        16 May 120

V.  Geomagnetic A Indices
Observed Afr/Ap 15 May  010/008
Estimated Afr/Ap 16 May  010/011
Predicted Afr/Ap 17 May-19 May  011/015-008/008-007/008

VI.  Geomagnetic Activity Probabilities 17 May-19 May
A.  Middle Latitudes
Active                30/15/15
Minor Storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/25/25
Major-severe storm    40/25/25