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23 September 2001
20010922 Week Rotation Today Rotation Week 20010924

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
No Prediction Found

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
McIntosh Class
Sunspot Area
Number of Spots
09616 S12W78
βγ/βγ Fso/Fao 0160/0120 09/11 -
09620 N12W24
βγ/βγ Dao/Dko 0110/0140 06/10 -
09621 N15W18
βγ/βγ Cao/Dao 0180/0150 09/06 -
09622 N12W46
βγ/βγ Dki/Dao 0300/0080 27/17 -
09624 N02W14
αγ/αγ Hsx/Hsx 0100/0090 01/02 -
09626 N25W28
βγ/βγ Bxo/Cso 0010/0030 04/07 -
09627 N02E03
βγ/βγ Cso/Cao 0050/0050 05/03 -
09628 S17E11
βγ/βγ Fac/Fkc 0630/0790 58/44 -
09629 N26W16
βγ/βγ Dso/Dao 0040/0050 10/09 -
09631 N08W57
βγ/βγ Dao/Dac 0050/0120 09/15 -
09632 S18E31
βγ/βγ Dko/Dki 0710/0640 20/13 -
09633 N23E61
αγ/αγ Hsx/Hsx 0090/0090 01/01 -
09634 N12E62
βγ/βγ Dao/Dao 0090/0090 04/04 -
09635 N22W01
βγδ/- Bxo/--- 0010/---- 03/-- -

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

Events not associated with currently named NOAA regions: None

Note: The tabulated data are based on the most recent NOAA/USAF Active Region Summary issued on 23-Sep-2001 00:30 . 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 23-Sep-2001 23:30 .