Product: Weekly Highlights and Forecasts
:Issued: 2026 Mar 30 0230 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact www.swpc.noaa.gov/content/subscription-services
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# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 23 - 29 March 2026
Solar activity reached moderate levels on 26 and 28 Mar with low levels observed on 23-25, 27, and 29 Mar.
Region 4405 (N26, L=178, class/area=Ehi/330 on 28 Mar) was the most active of the period, producing nine C-class flares and a long-duration M1.3 flare at 28/0416 UTC that was accompanied by a Type II radio sweep (estimated velocity 868 km/s) and a CME first seen in LASCO C2 imagery at 28/0336 UTC. Region 4403 (N16, L=206, class/area=Hsx/120 on 28 Mar) was responsible for the most powerful event of the period, an M3.9/1n flare at 26/0623 UTC, which was associated with a Type II radio sweep (estimated velocity 607 km/s), a 1,600 sfu radio burst at 245 MHz, and a CME first visible in LASCO C2 imagery at 26/0648 UTC. Neither CME was determined to have an Earth-directed component.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit reached high levels throughout the period 23-29 Mar with peak of 12,800 pfu observed at 27/1515 UTC.
Geomagnetic field activity ranged from quiet to G1 (Minor) storm levels. G1 storm conditions were observed 23 Mar due to the negative polarity coronal hole high-speed stream (-CH HSS) influences. Active levels were observed on 24 Mar under the continuing -CH HSS. On 25 Mar, G1 storming levels were reached again; while residual -CH HSS effects were present, the activity was primarily driven by the arrival of a CME likely associated with a filament eruption on 22 Mar. Conditions waned to unsettled levels on 26 Mar and quiet levels on 27 Mar as HSS influences subsided. Activity remained quiet to unsettled on 28 Mar. On 29 Mar, the field returned to active levels preceding a solar sector boundary crossing (SSBC) and the onset of a positive polarity CH HSS (+CH HSS).
Forecast of Solar and Geomagnetic Activity 30 March - 25 April 2026
Solar activity is expected to be is expected to be at low levels, with a varying chance for M-class (R1-R2/Minor-Moderate) flares through 25 Apr.
No proton events are expected at geosynchronous orbit, barring any significant, non-recurrent solar activity.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 30-31 Mar, 04-09 Apr, 11-16 Apr, and 18-25 Apr. Normal to moderate flux levels are expected to prevail throughout the remainder of the period.
Geomagnetic field activity is expected to reach G1 (Minor) geomagnetic storm levels on 30 March due to the influence of a positive polarity CH HSS (+CH HSS). Periods of G1 storming are likely on 04 April in response to a negative polarity CH HSS (-CH HSS). Further G1 storm periods are anticipated on 09 and 11 Apr,
with likely G2 (Moderate) storm levels on 10 April, due to + CH HSS influences. The field is expected to reach G2 storm levels again on 18 Apr, followed by G1 storm periods on 19 Apr, due to -CH HSS influences. Unsettled to active conditions are likely during the onset and waning phases of these streams.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2026 Mar 30 0230 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPweb C contact www.swpc.noaa.gov/content/subscription-services
#
# 27-day Space Weather Outlook Table
# Issued 2026-03-30
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2026 Mar 30 155 22 5
2026 Mar 31 152 12 4
2026 Apr 01 155 8 3
2026 Apr 02 155 5 2
2026 Apr 03 150 18 4
2026 Apr 04 145 22 5
2026 Apr 05 145 10 3
2026 Apr 06 135 15 4
2026 Apr 07 125 8 3
2026 Apr 08 118 7 2
2026 Apr 09 120 25 5
2026 Apr 10 110 40 6
2026 Apr 11 112 20 5
2026 Apr 12 115 12 4
2026 Apr 13 115 8 3
2026 Apr 14 110 7 2
2026 Apr 15 115 5 2
2026 Apr 16 115 4 2
2026 Apr 17 120 7 2
2026 Apr 18 122 48 6
2026 Apr 19 124 22 5
2026 Apr 20 130 12 4
2026 Apr 21 140 12 4
2026 Apr 22 150 8 3
2026 Apr 23 155 5 2
2026 Apr 24 160 8 3
2026 Apr 25 155 15 4
(NOAA)
