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20 July 2001
20010719 Week Rotation Today Rotation Week 20010721

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 N06W58
αγ/αγ Hsx/Hsx 0110/0100 01/01 -
09537 S08W80
βγ/βγ Cso/Cao 0030/0050 02/04 -
09538 N17W37
αγ/αγ Hax/Hax 0130/0180 01/01 -
09539 S20W88
αγ/βγ Hax/Cao 0110/0140 01/06 -
09540 N18W59
αγ/- Axx/--- 0010/---- 02/-- -
09541 N18W24
βγ/βγ Cso/Cso 0080/0100 04/05 -
09542 N08W01
βγ/βγ Cro/Bxo 0040/0020 08/04 -
09543 S23E08
βγ/βγ Eso/Eai 0230/0270 13/12 -
09545 N08W36
αγ/βγ Axx/Cso 0020/0030 01/03 -
09546 S17E05
βγ/βγ Eso/Dso 0090/0060 09/06 -
09548 N18E22
βγ/βγ Cso/Cso 0040/0020 04/02 -
09549 S04E31
αγ/αγ Hsx/Axx 0020/0020 01/01 -
09550 N07E10
βγ/βγ Bxo/Bxo 0010/0010 03/02 -
09551 N12W91
βγ/βγ Bxo/Bxo 0040/0040 02/02 -

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 20-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 20-Jul-2001 23:30 .