Sun unloads two strongest solar flares of 2013 in last 24 hours

Both yesterday and today, the sun belted out  X-class solar flares, the most intense type of flare. No flares thus far this calendar year have matched their strength.

Sunday’s flare was rated X1.7 according to NASA. Today’s flare – even stronger – reached X2.8.


Solar flare that erupted May 13. (NASA)

Writes NASA: An X2 is twice as intense as an X1, an X3 is three times as intense, etc.

(The other flares categories are M-class, which are medium strength, and C-class, which are small and relatively weak.)


Solar flare that erupted on May 12. (NASA)

Since the current solar cycle began Feb. 15, 2011, there have been 16 X-class flares (including today’s). The largest X-class flare in this cycle was an X6.9 on Aug. 9, 2011.  Today’s flare was the third strongest of this cycle.

Some flares generate blasts of plasma which propagate through space, known as coronal mass ejections.  If these CMEs are Earth-directed, they can trigger geomagnetic storms which may impact satellite communications and power grids, and spawn aurora.  Sunday’s flare produced a CME, but it was not pointed towards Earth.  Today’s flare originated from the same area.

“Given [today flare’s] location well off the Sun-Earth line, no Geomagnetic Storm activity is anticipated should a CME be launched,” writes NOAA’s Space Weather Prediction Center.

Related links:

Understanding space weather forecasts and the risk of solar storms

Are we ready yet for potentially disastrous impacts of space weather?

Jason is currently the Washington Post’s weather editor. A native Washingtonian, Jason has been a weather enthusiast since age 10.
Comments
Show Comments
Most Read Local

Heat Tracker

19
90-degree days year-to-date
Yearly Average
36
Record Most
67 (1980,2010)
Record Fewest
7 (1886,1905)
Last Year
24

At a Glance

Wed.

rain
-- /87°
Drop 30%

Thu.

rain
69° /84°
Drop 50%

Fri.

thunderstorms
73° /79°
Drop 40%

Sat.

thunderstorms
71° /82°
Drop 40%

Sun.

thunderstorms
70° /85°
Drop 30%

Mon.

thunderstorms
72° /87°
Drop 40%
National Airport
Dulles
BWI

Right Now

Next Story
Jason Samenow · May 13, 2013