Routine Space Environment Product (Daily)
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FXXX12 KWNP 210030

:Product: Forecast Discussion
:Issued: 2017 Jul 21 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 low as Region 2665 (S06, L=118) produced a C1 flare
at 20/0001 UTC. Otherwise, X-rays have been in the low B levels. A
narrow CME was observed with the C flare off the East limb shortly
following, but the event is not expected to impact Earth. No numbered
regions are currently on the visible disk. No Earth-directed CMEs were
observed in available coronagraph imagery.

Solar activity is expected to be very low on days one through three
(21-23 Jul).

Energetic Particle

.24 hr Summary...
The greater than 2 MeV reached high levels this period with a peak level
of 11443 pfu. The greater than 10 MeV proton flux was at or near
background levels this period.

The greater than 2 MeV electron flux is expected to reach high levels
over the next three days (21-23 Jul). The greater than 10 MeV proton
flux is forecast to be at or near background levels for days one through
three (21-23 Jul).

Solar Wind

.24 hr Summary...
Solar wind parameters were mostly at nominal levels, before indicating a
solar sector boundary crossing and CIR out ahead of an anticipated +CH
HSS. Solar wind speeds averaged near 380 km/s until around 20/1700 UTC
before increasing to near 500 km/s. Total field strength was between 1
and 7 nT while the Bz component was mostly northward until 20/0800 UTC,
when the Bt increased to 10nT. There was a short density increase noted
between 20/0800 - 20/1000 UTC. Bz remained predominately positive, with
isolated southward deviations to near -7 nT. The phi angle switched a
few times between negative and positive throughout the period, ending in
a positive orientation.

Solar wind parameters are expected to show an increase in solar wind
activity for days one through three (21-23 Jul), with increases in solar
wind velocity, temperature, and magnetic field, as the recurrent +CH HSS
is forecast to become geoeffective.


.24 hr Summary...
The geomagnetic field was quiet.

The geomagnetic field is forecast to be quiet to unsettled conditions
for day one (21 Jul), followed by unsettled to active conditions on day
two (22 Jul) as CH HSS effects are anticipated. A return to quiet to
unsettled conditions is forecast for day three (23 Jul) as CH effects
are forecast to begin waning. is the U.S. government's official web portal to all federal, state and local government web resources and services.