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29 April 2001
20010428 Week Rotation Today Rotation Week 20010430

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
09433 N17W64
βγδ/βγδ Fki/Fki 0780/0910 39/45 -
09435 S20W91
αγδ/βγδ Hax/Cao 0100/0160 01/03 -
09436 S10W33
αγδ/αγδ Hax/Hsx 0140/0160 01/01 -
09437 N10W33
βγδ/βγδ Cso/Cao 0020/0030 02/05 -
09439 S23W82
αγδ/αγδ Hrx/Hrx 0030/0020 02/01 -
09440 N08W22
βγδ/βγδ Dao/Dro 0030/0030 04/06 -
09441 N07E09
βγδ/βγδ Dao/Dao 0190/0150 16/15 -
09442 N28E20
αγδ/αγδ Hax/Hsx 0070/0060 01/01 -
09444 S11E53
αγδ/αγδ Hsx/Hsx 0060/0060 03/03 -
09445 N23E62
βγδ/βγδ Cao/Cao 0060/0060 04/04 -
09446 S05W36
βγδ/- Cro/--- 0010/---- 03/-- -

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 29-Apr-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 29-Apr-2001 23:30 .