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18 August 2001
20010817 Week Rotation Today Rotation Week 20010819

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
09570 S10W91
αγδ/αγδ Hax/Hsx 0070/0120 01/01 -
09573 S08W63
αγδ/αγδ Hsx/Hsx 0030/0030 01/01 -
09574 S04W91
αγδ/βγδ Hsx/Eao 0040/0150 01/03 -
09575 N11W16
βγδ/βγδ Cso/Cao 0100/0130 03/04 -
09577 N15W91
αγδ/βγδ Hsx/Dso 0010/0100 01/03 -
09579 S22W64
αγδ/βγδ Hsx/Cso 0020/0040 01/04 -
09580 N24E21
αγδ/αγδ Hax/Hsx 0090/0080 01/01 -
09581 S25W56
αγδ/βγδ Hsx/Cso 0020/0050 01/03 -
09582 N30E31
βγδ/αγδ Bxo/Axx 0020/0030 03/02 -
09584 S13E33
βγδ/βγδ Cao/Bxo 0040/0020 05/02 -
09585 N15E49
βγδ/βγδ Cso/Bxo 0060/0030 07/02 -
09586 S15W61
βγδ/βγδ Bxo/Bxo 0020/0020 02/02 -
09587 S11E42
αγδ/αγδ Hrx/Hrx 0020/0020 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 18-Aug-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 18-Aug-2001 23:30 .