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000
FXXX12 KWNP 210031
DAYDIS

:Product: Forecast Discussion
:Issued: 2017 Aug 21 0030 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 moderate levels (R1-Minor) due to an M1 flare
observed at 20/0152 UTC from new emerging Region 2672 (N05E75,
Dao/beta). This region also produced a C9 flare during the period. Due
to emerging Region 2672s proximity to the limb, accurate sunspot
analysis is ongoing.

Region 2671 (N12W06, Fkc/beta-gamma) also produced a few C-class flares,
the largest was a C2/Sn flare observed at 20/0750 UTC. Some weak trailer
spot growth was observed in the region. Limited LASCO C2 coronagraph
imagery indicated a narrow CME lifted off the E limb, first visible at
20/0236 UTC, but does not appear to have an Earth-directed component.
Further analysis will be performed as additional imagery becomes
available.

.Forecast...
For the next three days (21-23 Aug), solar activity is expected to be at
low levels with a 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 23,392 pfu observed at 20/1540 UTC. The greater than 10 MeV
proton flux continued at background values.

.Forecast...
The greater than 2 MeV electron flux is expected to be at normal to high
levels all three days of the forecast period (21-23 Aug) while the
greater than 10 MeV proton flux is expected to remain at background
levels.

Solar Wind

.24 hr Summary...
Solar wind parameters continued to show influences from a positive
polarity CH HSS. Solar wind speed averaged about 730 km/s, but indicated
a gradual decrease in speeds toward periods end. A peak speed of 813
km/s was observed early in the period at 20/0248 UTC. Total field
strength ranged between 2 and 5 nT while the Bz component varied between
+/- 4 nT. The phi angle remained in a predominately positive
orientation.

.Forecast...
The solar wind environment is expected to remain enhanced through day
one (21 Aug). A gradual return to a more nominal wind regime is expected
through days two and three (22-23 Aug) as CH HSS influences slowly wane.

Geospace

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

.Forecast...
The geomagnetic field is expected to be at predominately unsettled to
active levels on day one (21 Aug) and becoming quiet to unsettled levels
with isolated active intervals early on day two (22 Aug) as CH HSS
influence slowly wanes. By day three (23 Aug), mostly quiet conditions
are expected with isolated unsettled periods possible.