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


Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 18 Issued at 2200Z on 18 Jan 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 C5 event observed at
18/1707Z from Region 1654 (N07W59). There are currently 3 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for M-class flares on day one (19 Jan). Solar activity
is likely to be low on days two and three (20 - 21 Jan).

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed, as measured by the ACE spacecraft, reached a peak speed of
480 km/s at 18/1850Z. Total IMF reached 17.2 nT at 18/1132Z. The maximum
southward component of Bz reached -9.3 nT at 17/2351Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 2057 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to remain mostly quiet until late on day one (19 Jan), when the
geomagnetic field increases to quiet to unsettled conditions with a
chance for an active period with the arrival of the 16 Jan CME.
Unsettled to active conditions with a slight chance for a minor storm
period exists early on day two (20 Jan) with the 16 Jan CME. Conditions
begin to decrease to predominately quiet to unsettled levels starting
midday on day two (20 Jan). Conditions are expected to return to
predominately quiet with a possible unsettled period on day three (21
Jan).

III. Event probabilities 19 Jan-21 Jan
Class M 10/05/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 18 Jan 115
Predicted 19 Jan-21 Jan 115/115/110
90 Day Mean 18 Jan 122

V. Geomagnetic A Indices
Observed Afr/Ap 17 Jan 012/015
Estimated Afr/Ap 18 Jan 009/009
Predicted Afr/Ap 19 Jan-21 Jan 009/012-015/018-007/012

VI. Geomagnetic Activity Probabilities 19 Jan-21 Jan
A. Middle Latitudes
Active 25/35/15
Minor Storm 10/15/05
Major-severe storm 01/05/01
B. High Latitudes
Active 15/10/15
Minor Storm 30/30/25
Major-severe storm 35/55/20

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