Report of Solar Geophysical Activity (RSGA)

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 231 Issued at 2200Z on 19 Aug 2013

IA.  Analysis of Solar Active Regions and Activity from 18/2100Z to
19/2100Z: 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
19/0920Z from Region 1817 (S19W88). There are currently 10 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 (20 Aug, 21 Aug,
22 Aug).

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z: 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 550km/s at
18/2231Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 6050 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (20 Aug), unsettled to
active levels on day two (21 Aug) and quiet to active levels on day
three (22 Aug). Protons greater than 10 Mev have a slight chance of
crossing threshold on day one (20 Aug).

III.  Event probabilities 20 Aug-22 Aug
Class M    25/25/25
Class X    05/05/05
Proton     10/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           19 Aug 128
Predicted   20 Aug-22 Aug 125/120/115
90 Day Mean        19 Aug 113

V.  Geomagnetic A Indices
Observed Afr/Ap 18 Aug  008/007
Estimated Afr/Ap 19 Aug  006/006
Predicted Afr/Ap 20 Aug-22 Aug  011/014-014/018-014/012

VI.  Geomagnetic Activity Probabilities 20 Aug-22 Aug
A.  Middle Latitudes
Active                10/25/20
Minor Storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/20/20
Minor Storm           25/35/35
Major-severe storm    20/30/30

Radio Events Observed 19 Aug 2013
A.  245 MHz Bursts
Start  End   Peak Flux  Time of Peak  Duration
0104   0104    210          0104        0000  
1329   1330    340          1329        0001  
1558   1559    600          1558        0001  
1726   1726    100          1726        0000  
1755   1755    190          1755        0000  
B.  245 MHz Noise Storms
No 245 MHz Noise Storms Observed.

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 2071
Begin Time: 2013 Aug 16 1800 UTC
Yesterday Maximum 2MeV Flux: 6050 pfu


NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/NOAAscales

Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

**** SPACE WEATHER OUTLOOK ****

Summary For August 12-18

R1 (Minor) radio blackouts were observed on 12 Aug and 17 Aug due to flare activity from active Regions 1817  and 1818 respectively.

G1 (Minor) geomagnetic storms were observed on 16 Aug due to effects from a coronal hole high speed stream (CH HSS).  

Outlook For August 19-25

A chance for R1 - R2 (Minor - Moderate) radio blackouts exists from 19 - 21 Aug due to possible continued flare activity from Region 1818.

A slight chance for a G1 (Minor) geomagnetic storm exists on 21 Aug due to a combination of CH HSS effects and possible effects from the 17 Aug coronal mass ejection.