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9 May 1999
19990508 Week Rotation Today Rotation Week 19990510

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
08525 N17W63
α/β Hsx/Cso 0150/0120 01/06 -
08526 N19W91
β/β Eao/Cso 0260/0050 05/05 - / M4.6(14:22)
08531 N19W05
β/β Cro/Bxo 0020/0010 04/03 -
08533 N04E20
β/β Cso/Cso 0040/0030 05/05 -
08534 S17E21
β/α Cso/Hsx 0060/0040 04/01 -
08535 N22E29
β/β Dho/Cho 0300/0260 04/03 -
08536 S24E12
β/β Dso/Cso 0070/0030 15/05 -
08537 N19W86
β/β Eao/Cso 0230/0040 07/09 M7.6(17:53)
/ C2.1(19:45)
08538 N11W60
β/β Cro/Cro 0050/0020 07/06 -
08539 N14E17
β/β Dso/Bxo 0050/0030 06/06 -
08540 S28E46
β/β Eao/Cso 0140/0060 05/03 -
08541 N22E54
β/- Eso/- 0130/- 09/- C2.8(02:51)
/ C4.2(14:01)

Class (HH:MM) -Today
Class (HH:MM) -Yesterday

Events not associated with currently named NOAA regions: C2.5(04:32) C3.0(09:38) C3.2(10:37) M1.0(11:52) C3.7(14:05) C2.0(00:13) C3.1(02:48) M1.6(10:36) C2.0(21:11) C2.8(22:01) C5.0(23:59)

Note: The tabulated data are based on the most recent NOAA/USAF Active Region Summary issued on 09-May-1999 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 09-May-1999 23:30 .