Routine Space Environment Product (Daily)
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FXXX12 KWNP 230031

:Product: Forecast Discussion
:Issued: 2017 May 23 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 very low. Region 2656 (N11W16, Axx/alpha) and Region
2659 (N14E11, Cro/beta) continued to exhibit signs of decay and remained
inactive throughout the period. Region 2658 was split into two separate
spot groups. The first remained numbered as Region 2658 (S08W18,
Hsx/alpha), while the second was assigned as Region 2660 (S11W15,
Cro/beta). Region 2660 exhibited slight growth throughout the period,
but both remained inactive. Region 2659 (N14E11, Cro/beta) continued to
lose its trailer spots and remained inactive. No Earth-directed CMEs
were observed in available coronagraph imagery.

Solar activity is expected to be very low, with a slight chance for
C-class flares, throughout the forecast period (23-25 May).

Energetic Particles

.24 hr Summary...
The greater than 2 MeV electron flux was at high levels with a peak flux
of 26,098 pfu observed at 22/1650 UTC. The greater than 10 MeV
proton flux remained at background values.

The greater than 2 MeV electron flux is expected to reach high levels,
with a chance for very high levels, on all three days of the forecast
period (23-25 May) in response to elevated wind speeds from CH HSS
influence. The greater than 10 MeV proton flux is expected to continue
at background levels.

Solar Wind

.24 hr Summary...
Solar wind parameters were indicative of persistent CH HSS influence.
Solar wind speeds began the period near 620 km/s, decreased to as low as
510 km/s, then returned to near 600 km/s by the end of the period. Total
field (Bt) was steady near 6 nT, while the Bz component mainly
fluctuated between +/-4 nT, seeing a maximum southward deflection to -5
nT. The phi angle remained in a predominately negative sector during the

Solar wind parameters are expected to remain slightly enhanced, yet
continue to slowly diminish, during the forecast period (23-25 May) as
CH HSS influences continue.


.24 hr Summary...
The geomagnetic field was at quiet to unsettled levels as the waning
influence from the negative polarity CH HSS persisted.

The geomagnetic field is expected to be at quiet to unsettled levels on
days one and two (23-24 May) as CH HSS effects persist. A decrease to
mostly quiet levels is expected by day three (25 May) as the negative
polarity CH HSS moves out of a geoeffective position. is the U.S. government's official web portal to all federal, state and local government web resources and services.