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18 September 2001
20010917 Week Rotation Today Rotation Week 20010919

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
09608 S30W89
βγ/βγ Eki/Fki 0420/0550 10/15 -
09610 S12W89
βγ/βγ Dao/Eao 0150/0240 06/14 -
09616 S12W11
βγ/βγ Fki/Fhi 0270/0280 25/29 -
09617 N08W10
βγ/βγ Cso/Cso 0020/0040 04/04 -
09619 N15W43
βγ/βγ Cso/Cso 0020/0030 02/07 -
09620 N13E43
αγ/αγ Hax/Hsx 0180/0130 02/03 -
09621 N16E48
βγ/αγ Cao/Hsx 0130/0120 03/01 -
09622 N12E20
βγ/βγ Dso/Dso 0040/0040 05/05 -
09623 N21E32
αγ/αγ Hsx/Hsx 0020/0020 01/01 -
09624 N03E56
αγ/αγ Hsx/Hsx 0040/0040 01/01 -
09625 S30W26
βγ/- Cso/--- 0030/---- 05/-- -
09626 N25E33
αγ/- Hsx/--- 0010/---- 01/-- -
09627 N05E59
αγ/- Hax/--- 0060/---- 01/-- -
09628 S17E65
βγ/- Dao/--- 0160/---- 06/-- -

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-Sep-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-Sep-2001 23:30 .