Routine Space Environment Product (Daily)
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FXXX12 KWNP 200030

:Product: Forecast Discussion
:Issued: 2014 Sep 20 0030 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
#             Forecast Discussion
Solar Activity

.24 hr Summary...
Solar activity was at low levels. New Region 2171 (S09E65, Dso/beta)
produced the largest event of the period, a C3 flare at 19/1832 UTC. A
few other nominal C-level enhancements were also observed. All other
regions were either stable or in decay, and all were unremarkable. An
approximately 18 long filament, centered near S22E36, disappeared from
H-alpha between  ~19/0700 and ~19/1100 UTC. However, based on available
imagery, analysis does not indicate any Earth-directed coronal mass
ejections (CMEs) during the period.

Solar activity is likely to be low with slight chance for an M-class
flare (R1-Minor)for the next three days (20-22 Sep).

Energetic Particle

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

The greater than 10 MeV proton flux at geosynchronous orbit is expected
to be at or near background levels (Below S1-Minor) for the next three
days (20-22 Sep). The greater than 2 MeV electron flux at geosynchronous
orbit is expected to be at normal to moderate levels over the next three
days (20-22 Sep).

Solar Wind

.24 hr Summary...
Solar winds observed at L1 by Ace reported parameters that began the
period at nominal levels, before a density increased marked the onset of
an undefined solar wind feature. Density increased to an average near 40
(p/cc) between 19/0400 and 19/0700, before returning to low values, near
5 (p/cc). Bt increased from near 5nT to 17nT, and Bz fluctuated randomly
and frequently between 15nT and -13nT. Solar wind speeds began an
increase at around 19/0200 UTC from near 350 km/s to an average near 510
km/s between 19/1600 and 19/2100 UTC. The temperature showed an increase
relative to the speed increase, suggesting that Ace/Earth are under the
influence of a coronal hole, high speed stream (CH/HSS). However Phi
measurements did not report a consistent polarity through the
enhancement, and the Bt increase was uncharacteristic of a CH. The
observed solar winds may be the influence of either the glancing flank
of the anticipated CME from 13 Sep - originally believed to have missed
Earth - or a position near the edge of the non-recurrent CH/HSS from CH
92 (negative polarity), or a combination of both.

Solar wind parameters are expected to remain enhanced for days one and
two (21-22 Sep). A return to nominal levels is expected by day three (22


.24 hr Summary...
The geomagnetic field was at unsettled to active levels with an isolated
period of G1 (Minor) storm conditions between 19/0300-19/0600 UTC. The
elevated geomagnetic activity was in response to sub-storming in the
nighttime sector.

The geomagnetic field is expected to be at unsettled to active levels on
day one (20 Sep) Quiet to unsettled conditions are forecast for day two
(21 Sep), and mostly quiet conditions are expected on day three (22
Sep). is the U.S. government's official web portal to all federal, state and local government web resources and services.