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22 September 2001
20010921 Week Rotation Today Rotation Week 20010923

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 S12W65
βγ/βγ Fao/Fao 0120/0180 11/18 -
09620 N11W10
βγ/βγ Dko/Dao 0140/0210 10/09 -
09621 N14W07
βγ/βγ Dao/Dao 0150/0180 06/10 -
09622 N12W32
βγ/βγ Dao/Dao 0080/0060 17/14 -
09624 N03W00
αγ/αγ Hsx/Hsx 0090/0100 02/01 -
09625 S30W65
αγ/βγ Axx/Bxo 0000/0010 01/02 -
09626 N25W15
βγ/βγ Cso/Bxo 0030/0040 07/07 -
09627 N03E16
βγ/βγ Cao/Cso 0050/0040 03/03 -
09628 S18E24
βγ/βγ Fkc/Fkc 0790/0800 44/33 -
09629 N26W03
βγ/βγ Dao/Dso 0050/0060 09/07 -
09631 N09W38
βγ/βγ Dac/Dao 0120/0060 15/09 -
09632 S17E42
βγ/βγ Dki/Eko 0640/0390 13/06 -
09633 N23E61
αγ/- Hsx/--- 0090/---- 01/-- -
09634 N12E62
βγ/- Dao/--- 0090/---- 04/-- -

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 22-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 22-Sep-2001 23:30 .