Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 20 Nov 2012


Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 325 Issued at 2200Z on 20 Nov 2012

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M1 event, with an
associated Earth-directed CME (estimated velocity of 664 km/s), observed
at 20/1241Z. There are currently 7 numbered sunspot regions on the disk.
Region 1618 (N08E14) has retained its beta-gamma magnetic complexity.
New Region 1620 (S08E59) was numbered.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels on days one, two, and three (21 Nov, 22 Nov, 23 Nov).

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: 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
461 km/s at 20/1958Z. Total IMF reached 7.8 nT at 19/2347Z. The maximum
southward component of Bz reached -7.2 nT at 20/1725Z. Electrons greater
than 2 MeV at geosynchronous orbit reached a peak level of 1277 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at mostly quiet levels for the next three days (21 Nov, 22 Nov, 23
Nov). Protons have a slight chance to cross alert threshold on days one,
two, and three (21 Nov, 22 Nov, 23 Nov) due to expected solar flare
activity from Region 1618. Further analysis is needed to determine the
geoeffectiveness of today's CME.

III. Event probabilities 21 Nov-23 Nov
Class M 70/70/70
Class X 15/15/15
Proton 15/15/15
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Nov 141
Predicted 21 Nov-23 Nov 140/135/135
90 Day Mean 20 Nov 122

V. Geomagnetic A Indices
Observed Afr/Ap 19 Nov 003/005
Estimated Afr/Ap 20 Nov 009/012
Predicted Afr/Ap 21 Nov-23 Nov 006/005-006/005-007/009

VI. Geomagnetic Activity Probabilities 21 Nov-23 Nov
A. Middle Latitudes
Active 05/05/10
Minor Storm 01/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 10/10/20
Major-severe storm 05/05/20

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