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18 August 2002
20020817 Week Rotation Today Rotation Week 20020819

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
10063 N18W76
α/βγδ Hsx/Dso 0070/0100 01/06 -
10066 N13W50
β/βγδ Dso/Dso 0050/0090 13/17 -
10067 N12W34
β/βγδ Eai/Esi 0160/0200 28/32 -
10068 S08W34
β/βγδ Eso/Eso 0040/0050 06/03 -
10069 S07W17
βγδ/βγδ Ekc/Ekc 1950/1750 58/37 -
10076 N12W03
αγδ/αγδ Hsx/Hsx 0020/0020 01/01 -
10078 S14W67
βγδ/βγδ Cro/Dso 0060/0060 02/05 -
10079 S21E04
βγδ/βγδ Eao/Dso 0150/0140 23/12 -
10080 N16E16
βγδ/βγδ Dao/Dso 0140/0170 11/09 -
10081 N17E33
αγδ/βγδ Hrx/Dro 0020/0050 02/02 -
10082 N21W08
αγδ/αγδ Hrx/Hrx 0020/0020 02/02 -
10083 S18E53
βγδ/βγδ Cao/Cao 0050/0050 02/02 -
10084 S16E50
αγδ/- Hax/--- 0110/---- 01/-- -

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-Aug-2002 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-Aug-2002 23:30 .