Product: Weekly Highlights and Forecasts
:Issued: 2026 Mar 16 0302 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC cweb ontact www.swpc.noaa.gov/content/subscription-services
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 09 - 15 March 2026
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Solar activity was at low to moderate levels with a total of 37 C-class flares and 2 M-class flares observed. The largest flares of the period were an M1.2 flare on 13/0955 UTC from Region 4384 (N10, L=150, class/area Eho/300 on 03 Mar), a C8.9/1n flare on 13/2023 from Region 4392 (S15, L=017, class/area Cso/170 on 15 Mar), and an M1.0/Sf flare on 15/0939 UTC from Region 4392. The most active region of the period was Region 4381 (N08, L=173, class/area Eao/220 on 03 Mar), which produced a long-duration C8.0 flare on 13/1518 UTC in addition to 11 other weak C-class events.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 09 - 13 Mar and 15 Mar with a peak flux of 2,940 pfu observed at 12/1545 UTC. Normal to moderate levels were observed on 14 Mar.
Geomagnetic field activity ranged from quiet to G2 (Moderate) storm levels throughout the 09-15 Mar period. The week began at quiet to unsettled levels on 09 Mar, with active conditions observed on 10-11 Mar due to the influence of a negative polarity coronal hole high speed stream (CH HSS). Conditions returned to mostly quiet to unsettled levels by 12 Mar. Activity intensified midday on 13 Mar, reaching G1 (Minor) to G2 (Moderate) storm levels following the onset of a positive polarity CH HSS. These storming levels continued through the first half of 14 Mar before waning to unsettled and active levels later in the day. On 15 Mar, the field reached active levels early in the period, followed by a return to quiet and unsettled conditions as positive polarity CH HSS effects gradually diminished.
Solar wind parameters reflected the influence of two distinct CH HSS regimes during the period. The week began under the influence of a negative polarity CH HSS, with solar wind speeds initially ranging between 450-500 km/s before gradually declining to ambient levels near 400 km/s by 12 Mar. Total magnetic field (Bt) remained mostly around 6 nT during this interval, while the North-South (Bz) component saw periodic southward deflections to -7 nT. A solar sector boundary crossing (SSBC) occurred early on 13 Mar, indicated by a shift in the phi angle from the towards to away sector. This was immediately followed by the onset of a more powerful positive polarity CH HSS. Solar wind speeds rose sharply from 400 km/s to a peak of 725 km/s on 14 Mar. During this period, Bt reached 13 nT and the Bz component reached a maximum southward deflection of -10 nT.
By 15 Mar, solar wind speeds began a slow decline but remained elevated near 600 km/s through the end of the period.
Forecast of Solar and Geomagnetic Activity 16 March - 11 April 2026
Solar activity is expected to be at low levels, with a slight chance for M-class (R1-R2/Minor-Moderate) flares throughout the outlook period. Elevated probabilities are related to the flare potential of both currently observed spot groups as well as the potential from returning regions.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 16-20, 22-30 Mar, 04-09, and 11 Apr due to the influence of multiple, recurrent, CH HSSs. The remainder of the outlook period is likely to be at normal to moderate levels.
Geomagnetic field activity levels are likely to reach G1 (Minor) geomagnetic storm levels on 22 Mar, 04 Apr, 09 Apr, and 11 Apr due to CH HSS influences. G2 (Moderate) geomagnetic storm levels are likely on 11 Mar and 10 Apr due to CH HSS influences. Unsettled to active levels are likely on 16-18, 20, 23-27, 30-31 Mar, and 03 and 05-07 Apr. All elevated levels of geomagnetic activity are associated with the anticipated influence of multiple, recurrent, CH HSSs. The remainder of the outlook period is likely to be at mostly quiet levels.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2026 Mar 16 0302 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services
#
# 27-day Space Weather Outlook Table
# Issued 2026-03-16
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2026 Mar 16 108 15 4
2026 Mar 17 108 10 3
2026 Mar 18 105 8 3
2026 Mar 19 105 5 2
2026 Mar 20 105 10 3
2026 Mar 21 100 35 5
2026 Mar 22 102 25 5
2026 Mar 23 105 15 4
2026 Mar 24 110 15 4
2026 Mar 25 100 18 5
2026 Mar 26 110 10 3
2026 Mar 27 120 8 3
2026 Mar 28 125 5 2
2026 Mar 29 125 5 2
2026 Mar 30 125 15 4
2026 Mar 31 125 10 3
2026 Apr 01 130 5 2
2026 Apr 02 135 5 2
2026 Apr 03 140 18 5
2026 Apr 04 135 20 5
2026 Apr 05 135 8 3
2026 Apr 06 130 15 4
2026 Apr 07 135 8 3
2026 Apr 08 130 5 2
2026 Apr 09 125 25 5
2026 Apr 10 120 40 6
2026 Apr 11 115 20 5
(NOAA)
