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 21 April 2011
⇐20110420 ⇐Week ⇐Rotation Today Rotation⇒ Week⇒ 20110422⇒

NOAA
7 Active Regions
11190
11191
11193
11195
11196
11197
11198

Flare Forecast
Flare Forecast
MM MotD

Coronal Holes
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

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.


Today's/Yesterday's NOAA Active Regions
NOAA Number
Latest
Position
Hale
Class
McIntosh Class
Sunspot Area
[millionths]
Number of Spots
Recent
Flares
11190 N14W91
(919",229") 		βγ/βγ Cao/Dko 0060/0260 02/04 -
11191 N07W53
(753",46") 		αγ/βγ Hrx/Cso 0015/0050 01/05 -
11193 N16W34
(511",168") 		βγ/βγ Ehi/Eki 0300/0350 26/26 - / C1.5(17:38)
11195 S17E41
(-596",-359") 		βγ/βγ Dai/Dao 0100/0020 07/01 C4.5(21:51)
C4.9(14:37)
C8.5(09:38)
C1.0(08:31)
/ C1.0(03:46)
11196 S27E55
(-693",-486") 		βγ/βγ Dao/Dao 0080/0080 04/04 -
11197 S16E43
(-623",-341") 		αγ/- Axx/--- 0010/---- 01/-- -
11198 S26W52
(673",-477") 		αγ/- Bxo/--- 0010/---- 04/-- -

Class (HH:MM) -Today
Class (HH:MM) -Yesterday

Events not associated with currently named NOAA regions: C4.0(19:30)

Note: The tabulated data are based on the most recent NOAA/USAF Active Region Summary issued on 21-Apr-2011 00:30 UT . The greyed out and light-blue entries are values from the previous day. Slashed cells indicate that the active region has no spots. The latest positions of the active regions are given in both heliographic and heliocentric co-ordinates. The region positions are valid on 21-Apr-2011 20:30 UT .