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12 February 2012
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NOAA
5 Active Regions

Flare Forecast
Welcome to the Flare Prediction System. This page lists the active regions present on the Sun today, together with their probability of producing C-, M-, or X-class events. Flare probabilities are calculated using NOAA Space Weather Prediction Center data combined over 1969-1976 and 1988-1996 (details of which can be found in Bloomfield et al., 2012, The Astrophysical Journal Letters, 747, L41, along with full forecast verification testing). The percentage probabilities are based on the number of flares produced by regions classified using the McIntosh classification scheme (McIntosh, P., 1990, Solar Physics, 125, 251) during cycles 21 and 22. For example, over both time periods there were 377 regions classified Eai. As this class produced 131 M-class events, the mean M-class flare rate is ~131/377 or ~0.347 flares per day. Assuming the number of flares per unit time is governed by Poisson statistics, we can estimate a flaring probability for the following 24-hours using P( one or more flares ) = 1 - exp( -mean ), i.e., P = 1 - exp( -0.347 ) ~ 0.29, or 29% for an Eai class region to produce one or more M-class flares in the next 24-hours.

See Gallagher, P. T., Moon, Y.-J., Wang, H., Solar Physics, 209, 171, (2002),
Wheatland, M. S., 2001, Solar Physics, 203, 87 and Moon et al., 2001, Journal of Geophysical Research-Space Physics, 106(A12) 29951 for further details.

Click here for a description of the various active region classifications from the Royal Observatory of Belgium.

Region Flare Probabilities (%)
Number McIntosh C-class M-class X-class
11416 Dhi 30(90) 13(30) 0(5)
11417 Cro 9(15) 1(0) 0(0)

NOTE: Occurrence of '...' indicates that McIntosh class was not observed in the period over which the Poisson flare rate statistics were determined. Values in parantheses/brackets give the NOAA/SWPC forecast probabilities for the occurrence of one or more C-, M-, or X-class flares. When viewed in real-time and before 22:00 UT, NOAA predictions are valid up to 22:00 UT on the current date. When viewed in real-time after 22:00 UT (or when viewing past dates), NOAA predictions are valid up to 22:00 UT on the following date. The most recent data can also be found at NOAA's 3-day Space Weather Predictions page.

Please contact Peter Gallagher if you have any comments or questions regarding this research.


IDL Access

Today's NOAA Active Regions
Group Number
Location
Hale
Class
McIntosh Class
Sunspot
Area
Number of Spots
Flares
History
11416 S19W16
(248",-412")
βγ/βγ Dhi/Dsi 0400/0100 27/17 -
11417 N16E30
(-457",164")
βγ/βγ Cro/Bxo 0020/0010 03/02 /C1.4(08:49)
C7.9(09:55)
C1.5(10:41)
C2.7(15:55)
C7.7(18:47)
11418 S24W01
(15",-489")
βγ/- Bxo/--- 0010/---- 04/-- -
11419 N28E55
(-687",384")
βγ/- Cso/--- 0080/---- 04/-- -
11420 N13E55
(-758",147")
αγ/- Hsx/--- 0050/---- 01/-- -

Events not associated with currently named NOAA regions: C1.3(04:42) C1.6(06:53) C3.9(14:37) /C5.3(19:08) C2.7(20:38) C2.7(23:26)

Note: The tabulated data are based on the most recent NOAA/USAF Active Region Summary issued on 12-Feb-2012 00:30 UT , the values to the right of the forward slashes representing yesterdays values or events. Regions with no data in above property fields have decayed and exhibit no spots. The region positions are valid on 12-Feb-2012 22:00 UT .