:Product: 20000524RSGA.txt
:Issued: 2000 May 24 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Environment Center and the U.S. Air Force.
#
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY
SDF NUMBER 145 ISSUED AT 2200Z ON 24 MAY 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  23/2100Z
TO 24/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 8996 (S22W87)
PRODUCED AN M1 X-RAY FLARE AT 24/0546Z. AN OPTICALLY UNCORRELATED M1
FLARE OCCURRED AT 24/1152Z. THE LIKELY SOURCE FOR THIS FLARE WAS NEW
REGION 9017 (S14E76) WHICH HAS EXHIBITED FREQUENT SURGING FOR MOST
OF THE PERIOD. REGIONS 9002 (N19W51) AND 9004 (N12W61) CONTINUE TO
PRODUCE C-CLASS FLARES. NEW REGIONS 9015 (N13W08) AND 9016 (N26E46)
WERE ALSO NUMBERED TODAY.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO CONTINUE
AT LOW TO MODERATE LEVELS. ANY ONE OF A NUMBER OF REGIONS ON OR NEAR
THE WEST LIMB ARE CAPABLE OF PRODUCING AN ISOLATED M-CLASS FLARE.
NEW REGION 9017 MAY ALSO PRODUCE AN M FLARE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 23/2100Z TO 24/2100Z:
THE GEOMAGNETIC FIELD WAS AT ACTIVE TO SEVERE STORM LEVELS. THE
TRANSIENT OBSERVED TO PASS ACE AT 23/1625Z HERALDED THE BEGINNING OF
A COMPACT AND COMPLEX MAGNETIC STRUCTURE. A NUMBER OF STRONG
NORTHWARD TO SOUTHWARD VARIATIONS IN BZ OCCURRED THAT REACHED
EXTREMES OF -36 NT TO +30 NT. CONDITIONS IMPROVED BY 24/12Z BUT
SOLAR WIND VELOCITY REMAINS ELEVATED RESULTING IN ACTIVE TO MINOR
STORM CONDITIONS PERSISTING THROUGH LATE IN THE PERIOD. THIS
ACTIVITY IS PRESUMED TO BE ASSOCIATED WITH THE C7/1N FLARE THAT
OCCURRED AT 20/0535Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT ACTIVE TO MINOR STORM LEVELS THROUGH DAY ONE AS
THE PRESENT STORM SUBSIDES. UNSETTLED CONDITIONS ARE EXPECTED ON
DAYS TWO AND THREE.
III.  EVENT PROBABILITIES 25 MAY-27 MAY
CLASS M    50/50/40
CLASS X    10/10/05
PROTON     05/05/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           24 MAY 189
PREDICTED   25 MAY-27 MAY  180/175/165
90 DAY MEAN        24 MAY 196
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 23 MAY  019/022
ESTIMATED AFR/AP 24 MAY  048/070
PREDICTED AFR/AP 25 MAY-27 MAY  018/030-010/010-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 25 MAY-27 MAY
A.  MIDDLE LATITUDES
ACTIVE                40/40/30
MINOR STORM           40/20/10
MAJOR-SEVERE STORM    10/05/01
B.  HIGH LATITUDES
ACTIVE                40/50/40
MINOR STORM           45/30/20
MAJOR-SEVERE STORM    15/10/05