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21 October 2001
20011020 Week Rotation Today Rotation Week 20011022

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
09658 S15W87
β/βγδ Dao/Fao 0110/0230 07/18 -
09661 N15W62
βγ/βγδ Eso/Eki 0410/0620 15/21 -
09662 N11W91
βγ/βγδ Dso/Dso 0060/0070 02/05 -
09667 N26W24
αγ/βγδ Hrx/Cso 0010/0040 01/05 -
09669 N14W13
βγ/βγδ Eai/Eai 0150/0170 32/27 -
09670 S19E05
βγ/βγδ Fao/Fko 0470/0530 17/20 -
09671 N15W23
βγ/βγδ Dso/Dao 0080/0100 15/14 -
09672 S20E26
βγ/αγδ Dao/Hax 0150/0160 08/04 -
09673 N03E32
βγ/αγδ Cao/Hax 0070/0130 04/01 -
09674 S08E06
βγ/βγδ Dso/Bxo 0050/0060 07/04 -
09675 S14E55
αγ/αγ Hsx/Hsx 0030/0030 01/01 -
09676 N13E56
βγ/βγ Cao/Cao 0070/0070 01/01 -

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 21-Oct-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 21-Oct-2001 23:30 .