Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 18 July 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 199 Issued at 2200Z on 18 Jul 2013

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 C2 event observed at
18/1823Z from Region 1800 (S10E63). There are currently 7 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a
slight chance for an M-class flare on days one, two, and three (19 Jul,
20 Jul, 21 Jul).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: 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
560 km/s at 18/1732Z. Total IMF reached 18 nT at 18/1345Z. The maximum
southward component of Bz reached -11 nT at 18/1300Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 2285 pfu.

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

III. Event probabilities 19 Jul-21 Jul
Class M 15/15/15
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Jul 115
Predicted 19 Jul-21 Jul 120/125/125
90 Day Mean 18 Jul 121

V. Geomagnetic A Indices
Observed Afr/Ap 17 Jul 005/004
Estimated Afr/Ap 18 Jul 010/015
Predicted Afr/Ap 19 Jul-21 Jul 013/020-013/020-011/015

VI. Geomagnetic Activity Probabilities 19 Jul-21 Jul
A. Middle Latitudes
Active 45/45/35
Minor Storm 20/20/15
Major-severe storm 05/05/01
B. High Latitudes
Active 10/10/10
Minor Storm 25/25/30
Major-severe storm 65/65/50