Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 November 2012


Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 329 Issued at 2200Z on 24 Nov 2012

IA. Analysis of Solar Active Regions and Activity from 23/2100Z to
24/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3/1n event observed at
24/1340Z from Region 1618 (N08W41) accompanied by a Type II radio sweep
(685 km/s). No coronagraph imagery was available for analysis at the
time of this report. Region 1618 showed signs of decay during the
period, but retained weak beta-gamma-delta characteristics. New Region
1621 (N15E76) was numbered today and is currently a simple Hsx type with
alpha magnetic characteristics. The remaining 3 regions were stable.
Other than the potential CME associated with the Type II sweep noted
above, no earth-directed CMEs were detected.

IB. Solar Activity Forecast: Solar activity is expected to be at low
levels on days one, two, and three (25 Nov, 26 Nov, 27 Nov) with a
diminishing chance for an isolated M-flare from Region 1618 as it
continues to decay.

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. The
maximum solar wind speed at the ACE spacecraft was 439 km/s at 24/1137Z.
Total IMF reached 17.1 nT at 23/2216Z. The maximum southward component
of Bz reached -10.3 nT at 24/0621Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 789 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to range from quiet to minor storm levels over the next three days (25
Nov, 26 Nov, 27 Nov). The 21 November CME is expected to become
geoeffective late on 24 or early on 25 November. Unsettled to active
periods with an isolated minor storm period are expected on day 1 (25
November). Conditions are expected to return to quiet to unsettled
levels on day 2 (26 November). The 23 November CME is expected to
arrive on day 3 (27 November), bringing unsettled to active conditions
with a slight chance for an isolated minor storm period, particularly at
high latitudes.

III. Event probabilities 25 Nov-27 Nov
Class M 30/30/30
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 24 Nov 118
Predicted 25 Nov-27 Nov 120/115/110
90 Day Mean 24 Nov 123

V. Geomagnetic A Indices
Observed Afr/Ap 23 Nov 006/006
Estimated Afr/Ap 24 Nov 013/015
Predicted Afr/Ap 25 Nov-27 Nov 015/018-008/005-013/015

VI. Geomagnetic Activity Probabilities 25 Nov-27 Nov
A. Middle Latitudes
Active 30/10/25
Minor Storm 15/05/10
Major-severe storm 05/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/15/25
Major-severe storm 50/15/35

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