National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXXX12 KWNP 200031
DAYDIS

:Product: Forecast Discussion
:Issued: 2017 Oct 20 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 remained very low. The visible disk was spotless. No
Earth-directed CMEs were observed in coronagraph imagery.

.Forecast...
Solar activity is expected to continue at very low levels the next three
days (20-22 Oct), with a slight chance for C-class flares on days two
and three (21-22 Oct) with the return of old Regions 2682 and 2683.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux reached high levels with a peak
flux of 12,600 pfu observed at 19/1420 UTC. The greater than 10 MeV
proton flux remained at background values.

.Forecast...
The greater than 2 MeV electron flux is expected to be at high to
very high levels for the next two days (20-21 Oct), then decrease to
normal to moderate levels by day three (22 Oct) with the redistribution
of electrons ahead of a recurrent CH HSS.

The greater than 10 MeV proton flux is expected to remain at background
levels all three days (20-22 Oct).

Solar Wind

.24 hr Summary...
Solar wind parameters were just above background levels and were
suggestive of intermittent influences from the northern crown HSS. Total
magnetic field strength ranged from 3-11 nT. The Bz component deflected
southward several times throughout the period, and reached a maximum
southward deviation of -9 nT. Solar wind speeds were steady around 350
km/s until 19/0430 UTC, then steadily increased to over 465 km/s by the
end of the period. Phi angle fluctuated between solar sectors.

.Forecast...
Solar wind parameters are expected to remain marginally enhanced into
day one (20 Oct) as Earth continues to interface with the northern crown
HSS. The first part of day two (21 Oct) is expected to be at
near-background levels as these effects wane, then become enhanced late
in the day due to the onset of recurrent, negative polarity CH HSS.
Levels are expected to remain enhanced into day three (22 Oct) due to
ongoing CH HSS effects.

Geospace

.24 hr Summary...
The geomagnetic field was at quiet to unsettled levels.

.Forecast...
Unsettled to active levels are expected early on day one (20 Oct) as a
result of elevated solar wind speeds. Quiet to unsettled levels are
anticipated late in the day as wind speeds settle. Day two (21 Oct) is
expected to be at mostly quiet levels, becoming unsettled late in the
day, due to the anticipated arrival of a recurrent, negative polarity CH
HSS. Active levels are expected into day three (22 Oct) as CH HSS
effects persist.