Routine Space Environment Product (Daily)
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FXXX12 KWNP 200031

:Product: Forecast Discussion
:Issued: 2017 Aug 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 remained at low levels. Multiple C-class flare activity
was observed, particularly from an area of enhanced brightening on or
just behind the E limb. Region 2671 (N12E08, Fkc/beta-gamma) also
produced a few C-class flares. The largest event of the period was a
C7/Sf flare, with an associated Type II (928 km/s) radio sweep, observed
at 19/2155 UTC from Region 2671. Coronal dimming was observed to the
north of the Region in SDO/AIA 193 imagery beginning at 19/2143 UTC
suggesting a CME was lifting off. We are currently awaiting updated
coronagraph imagery to determine if there is an Earth-directed

Region 2671 exhibited some elongation along its E-W axis with some minor
intermediate spot consolidation.

For the next three days (20-22 Aug), solar activity is likely to be at
low levels with a slight chance of M-class flares (R1-R2; Minor-Moderate
radio blackouts).

Energetic Particles

.24 hr Summary...
The greater than 2 MeV electron flux was at normal to high levels with a
peak flux of 8,118 pfu observed at 19/1815 UTC. The greater than 10 MeV
proton flux continued at background values.

The greater than 2 MeV electron flux is expected to be at normal to high
levels all three days of the forecast period (20-22 Aug) while the
greater than 10 MeV proton flux is expected to remain at background

Solar Wind

.24 hr Summary...
Solar wind parameters were indicative of positive polarity CH HSS
influence. Solar wind began the period near 600 km/s, steadily increased
to a peak of 814 km/s at 19/1630 UTC and gradually decreased to end the
period near 770 km/s. Total field strength ranged between 3-8 nT while
the Bz component reached a low value of -7 nT with periods of sustained
negative values. The phi angle remained in a predominately positive

The solar wind environment is expected to remain enhanced through day
one (20 Aug). A gradual return to a more nominal wind regime is expected
through days two and three (21-22 Aug) as CH HSS influences slowly wane.


.24 hr Summary...
The geomagnetic field was at unsettled to minor storm levels (G1-Minor)
due to positive polarity CH HSS influence.

The geomagnetic field is expected to be at predominately unsettled to
active levels on day one (20 Aug) with minor storm levels (G1-Minor)
expected early as CH HSS influence persists. Days two and three (21-22
Aug) are expected to be at quiet to isolated active levels as positive
polarity CH HSS influence persists. is the U.S. government's official web portal to all federal, state and local government web resources and services.