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000
FXXX12 KWNP 081230
DAYDIS

:Product: Forecast Discussion
:Issued: 2013 Dec 08 1230 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# http://www.swpc.noaa.gov/wwire.html
#
#             Forecast Discussion
#
Solar Activity

.24 hr Summary...
Solar activity was at low levels.  Only low level C-class flares were
observed.  Slight growth was observed in the intermediate and trailing
spots of Regions 1916 (S13W30, Dac/beta-gamma) and 1917 (S16E64,
Dai/beta).  The rest of the spotted regions were either stable or in
decay.  No Earth-directed coronal mass ejections (CMEs) were observed
during the period.

.Forecast...
Solar activity is expected to be low with a chance for M-class flares
(R1-Minor) for the forecast period (08-10 Dec).  The most likely Regions
to produce M-class activity are Regions 1916 or 1917.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux at geosynchronous orbit was at
normal to moderate levels. The greater than 10 MeV proton flux at
geosynchronous orbit was at background levels.

.Forecast...
The greater than 2 MeV electron flux at geosynchronous orbit is expected
to be at normal to moderate levels for days 1-2 (08-09 Dec) with high
levels possible on day 3 (10 Dec) due to coronal hole high speed stream
(CH HSS) activity.  The greater than 10 MeV proton flux at
geosynchronous orbit is expected to remain at background levels (Below
S1-Minor) for the forecast period (08-10 Dec).

Solar Wind

.24 hr Summary...
Solar wind conditions indicated the onset of a co-rotating interaction
region (CIR) followed by CH HSS and possible transient influence from
the 05 Dec CME.  The period began at nominal levels with solar wind
speeds in the 320 to 350 range and total field measurements between 1 nT
and 6 nT.  By approximately 07/2114 UTC, a slow increase in total field,
solar wind speed, temperature, and density was observed culminating in a
total field increase of 27 nT at 08/0219 UTC.  The Bz component went
southward to a maximum of -23 nT while solar wind speeds were near 500
km/s as the CIR reached its maximum strength.  Solar wind speed
continued near 500 km/s until a reverse shock occurred at 08/0730 UTC.
Solar wind speed increased again to a maximum of 651 km/s with total
field suddenly decreasing from 10 nT to 5 nT.  The reverse shock could
either be related to the CIR or the glancing blow that was expected from
the 05 Dec CME.  Phi angle was variable through the period until
approximately 08/0610 UTC when it moved into a mostly positive (away)
sector.

.Forecast...
Solar wind speeds are expected to continue to be enhanced on day 1 (08
Dec) under the influence of a positive polarity CH HSS and remain
elevated into day 2 (09 Dec).  A possible glancing blow from the 07 Dec
CME is expected to further enhance solar wind parameters by late on day
2 to early on day 3 (09-10 Dec).

Geospace

.24 hr Summary...
The geomagnetic field was at quiet to major storm levels due to a
combination of CIR, CH HSS, and possible effects from the 05 Dec CME.
Minor to major storm (G1-G2, Minor-Moderate) levels were observed during
08/0000-0300 UTC and 08/0300-0600 UTC periods.

.Forecast...
The geomagnetic field is expected to be at quiet to active levels with a
chance for Minor storm (G1-Minor) periods for the rest of the UTC day on
day 1 (08 Dec) due to continued CH HSS effects.  Quiet to active levels
with a slight chance for isolated minor storm (G1-Minor) periods are
expected on days 2 and 3 (09-10 Dec) due to combined CH HSS and CME
effects.