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21 July 2001
20010720 Week Rotation Today Rotation Week 20010722

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
09535 N06W72
αγ/αγ Hsx/Hsx 0120/0110 01/01 -
09537 S08W91
αγ/βγ Hrx/Cso 0030/0030 01/02 -
09538 N17W51
αγ/αγ Hax/Hax 0130/0130 01/01 -
09539 S20W91
αγ/αγ Hax/Hax 0120/0110 01/01 -
09540 N18W59
αγ/αγ Axx/Axx 0010/0010 02/02 -
09541 N16W42
βγ/βγ Cao/Cso 0070/0080 03/04 -
09542 N08W16
βγ/βγ Cro/Cro 0030/0040 08/08 -
09543 S23W07
βγ/βγ Eai/Eso 0270/0230 24/13 -
09545 N08W51
αγ/αγ Hrx/Axx 0010/0020 01/01 -
09546 S16W10
βγ/βγ Eai/Eso 0040/0090 10/09 -
09548 N17E10
βγ/βγ Dao/Cso 0090/0040 07/04 -
09549 S04E18
αγ/αγ Axx/Hsx 0020/0020 01/01 -
09551 N10W91
βγ/βγ Bxo/Bxo 0040/0040 03/02 -

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-Jul-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-Jul-2001 23:30 .