SOLAR ACTIVITY INTENSIFIES: So far today, sunspot AR2871 has produced two M-class solar flares, an M2 (1528 UT) and an M3 (0442 UT). The more powerful of the two flares is detailed below. Both explosions hurled CMEs into space, but perhaps not directly toward Earth. Glancing blows are possible on Sept. 26-27. Stay tuned for updates as more data become available.

M-CLASS SOLAR FLARE AND CME (UPDATED): Sunspot AR2871 exploded on Sept 23rd (0442 UT), producing a strong M3-class solar flare. NASA's Solar Dynamics Observatory recorded the extreme ultraviolet flash:



USAF observatories report Type II and Type IV solar radio bursts in the flare's immediate aftermath. This suggests that a CME was produced as well (because such radio bursts typically come from shock waves in a CME's leading edge). If so, the CME is probably heading toward Earth.

Solar wind
speed: 493.1 km/sec
density: 8.6 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1115 UT

X-ray Solar Flares
6-hr max: C3 0701 UT Sep24
24-hr: M1 1528 UT Sep23
explanation | more data
Updated: Today at: 1120 UT

MINOR GEOMAGNETIC STORM WATCH: NOAA forecasters say there is a 40% chance of minor G1-class geomagnetic storms on Sept. 26th when a high-speed stream of solar wind is expected to hit Earth's magnetic field.

The gaseous material is flowing from an equatorial hole in the sun's atmosphere. High-latitude sky watchers should be alert for auroras

🔥 Solar wind
speed: 540.3 km/sec
density: 8.0 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 0415 UT

X-ray Solar Flares
6-hr max: C1 0354 UT Sep25
24-hr: C3 0701 UT Sep24
explanation | more data
Updated: Today at: 0420 UT

Solar wind
speed: 505.5 km/sec
density: 7.0 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1950 UT

X-ray Solar Flares
6-hr max: C1 1917 UT Sep25
24-hr: C1 1917 UT Sep25
explanation | more data
Updated: Today at: 1955 UT

UPGRADED GEOMAGNETIC STORM WATCH: Earth's magnetic field might receive a double blow this weekend. First, a stream of solar wind is expected to hit on Sept. 26th. Next, a CME might graze Earth during the early hours of Sept. 27th. The combined effect could produce geomagnetic storms as strong as category G2 with auroras visible in northern-tier US states during the night of Sept. 26-27.

Solar wind
speed: 425.5 km/sec
density: 3.0 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 0419 UT

X-ray Solar Flares
6-hr max: B6 0039 UT Sep26
24-hr: C1 1917 UT Sep25
explanation | more data
Updated: Today at: 0425 UT

Solar wind
speed: 365.6 km/sec
density: 9.8 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1115 UT

X-ray Solar Flares
6-hr max: B2 0738 UT Sep27
24-hr: C1 1124 UT Sep26
explanation | more data
Updated: Today at: 1120 UT

UPDATED GEOMAGNETIC STORM FORECAST: NOAA forecasters say there is a 45% chance of G1 to G2-class geomagnetic storms today, Sept. 27th, in response to a passing CME. If a storm materializes, bright auroras can be expected around the Arctic Circle with a chance for sightings in northern-tier US states.

Solar wind
speed: 488.0 km/sec
density: 7.5 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 0540 UT

X-ray Solar Flares
6-hr max: B6 0540 UT Sep28
24-hr: B6 0540 UT Sep28
explanation | more data
Updated: Today at: 0545 UT

Solar wind
speed: 387.1 km/sec
density: 11.1 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 2330 UT

X-ray Solar Flares
6-hr max: C2 2156 UT Sep29
24-hr: C2 2156 UT Sep29
explanation | more data
Updated: Today at: 2335 UT

Solar wind
speed: 438.4 km/sec
density: 2.0 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 0700 UT

X-ray Solar Flares
6-hr max: B3 0103 UT Oct02
24-hr: B8 1100 UT Oct01
explanation | more data
Updated: Today at: 0705 UT

QUIET WEEKEND: Earth's magnetic field is quieting after yesterday's near miss by a passing CME. No geomagnetic storms are expected this weekend. Fortunately, Earth can make its own auroras without a CME.

Solar wind
speed: 416.5 km/sec
density: 3.6 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1950 UT

X-ray Solar Flares
6-hr max: B2 1807 UT Oct02
24-hr: B4 0054 UT Oct02
explanation | more data
Updated: Today at: 1955 UT

Solar wind
speed: 290.2 km/sec
density: 8.7 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 0645 UT

X-ray Solar Flares
6-hr max: B1 0358 UT Oct05
24-hr: B2 1556 UT Oct04
explanation | more data
Updated: Today at: 0650 UT

Solar wind
speed: 300.3 km/sec
density: 7.1 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 2010 UT

X-ray Solar Flares
6-hr max: B2 1909 UT Oct05
24-hr: B2 1909 UT Oct05
explanation | more data
Updated: Today at: 2015 UT

Solar wind
speed: 317.4 km/sec
density: 3.3 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1005 UT

X-ray Solar Flares
6-hr max: B3 0409 UT Oct07
24-hr: C5 0246 UT Oct07
explanation | more data
Updated: Today at: 1010 UT

Solar wind
speed: 294.4 km/sec
density: 6.9 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 0735 UT

X-ray Solar Flares
6-hr max: M1 0638 UT Oct09
24-hr: M1 0638 UT Oct09
explanation | more data
Updated: Today at: 0740 UT

Solar wind
speed: 290.5 km/sec
density: 10.6 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 2150 UT

X-ray Solar Flares
6-hr max: B6 2110 UT Oct09
24-hr: M1 0638 UT Oct09
explanation | more data
Updated: Today at: 2155 UT