FXXX12 KWNP 201231

DAYDIS



:Product: Forecast Discussion

:Issued: 2026 Mar 20 1230 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 very low levels with only B-flares. The only two

regions on the disk, Regions 4392 (S16W40, Cso/beta-gamma) and 4397

(N17E42, Cao/beta), both showed signs of magnetic flux consolidation and

cancellation.



No Earth-directed CMEs were observed in available coronagraph imagery.



.Forecast...

Solar activity is expected to be very low, with C-class flares likely,

on 20-22 Mar.





Energetic Particle



.24 hr Summary...

The greater than 2 MeV electron flux reached high levels, with a

peak of 4,941 pfu at 19/1710 UTC. The greater than 10 MeV proton flux

continued at background levels.



.Forecast...

The greater than 2 MeV electron flux is likely to decrease to

normal-moderate levels on 20-22 Mar, due to anticipated CME arrivals.

The greater than 10 MeV proton flux is expected to continue at

background values.





Solar Wind



.24 hr Summary...

Solar wind parameters reflected near background conditions until roughly

20/0130 UTC, when a mild disturbance arrived: Bt increased only 3 nT,

plateauing at 8 nT and the wind speed gradually increased to ~375 km/s.

This feature is most likely the anticipated arrival of the CME from 16

Mar. Over the rest of the reporting period, the solar wind environment

slowly enhanced to maximums of Bt ~ 19 nT and wind speed ~ 450 km/s, and

a slowly rotating Bz that periodically reached ~ -10 nT. The phi angle

was predominantly positive.



.Forecast...

The solar wind environment is expected to remain enhanced for the

remainder of 20 Mar. By 21 Mar, the CME from 18 Mar is expected to have

a more direct impact at Earth, in conjunction with the onset of a

negative polarity CH HSS. Elevated parameters are expected to continue

through 22 Mar as CME/CH HSS effects persist.





Geospace



.24 hr Summary...

The geomagnetic field was quiet to active.



.Forecast...

The geomagnetic field is expected to be at active to G2 (Moderate) storm

levels on 20 Mar as CMEs from 16-17 Mar are anticipated to arrive.

Additional G2 (Moderate) storm conditions are likely, with G3 (Strong)

conditions possible, on 21 Mar as the CME from 18 Mar is expected to

arrive in conjunction with the onset of a negative polarity CH HSS.

Unsettled to G1 (Minor) levels are expected on 22 Mar as CME/CH HSS

effects persist.