:Product: 19980527RSGA.txt
:Issued: 1998 May 27 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
:::::::::: CORRECTED COPY ::::::::::
SDF NUMBER 147 ISSUED AT 2200Z ON 27 MAY 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  26/2100Z
TO 27/2100Z:  SOLAR ACTIVITY WAS LOW. REGIONS 8224 (S24W90) AND 8226
(N18W66) PRODUCED SEVERAL C-CLASS FLARES INCLUDING A C7 LONG
DURATION EVENT AT 27/1335Z WITH MODERATE RADIO BURSTS. BOTH REGIONS
HAD A FLARE IN PROGRESS DURING THE X-RAY EVENT. LASCO IMAGERY
SHOWS A LARGE CORONAL MASS EJECTION ORIGINATING FROM THE NW. WELL
DEFINED POST FLARE LOOPS ARE OBVIOUS ON THE EIT IMAGES SUGGESTING
THAT REGION 8226 WAS THE PROBABLE SOURCE FOR THE LONG DURATION
EVENT. A MODERATE 8 FREQUENCY RADIO BURST AND TENFLARE ALSO
OCCURRED WITH THIS EVENT. REGION 8224 WAS SPOTLESS FOR MOST OF ITS
TRANSIT ON THE VISIBLE DISK BEFORE DEVELOPING RAPIDLY EARLY
YESTERDAY. SPOTS ARE NOW VISIBLE IN THIS REGION AS IT ROUNDS THE
WEST LIMB. REMAINING REGIONS HAVE BEEN QUIET.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. DRAMATIC GROWTH IN REGION 8224 WILL LIKELY ENSURE
CONTINUED C-CLASS ACTIVITY AND A DEVELOPING CHANCE FOR M-CLASS.
REGION 8226 WILL ALSO CONTINUE PRODUCING C-CLASS WITH A CHANCE OF
A M-CLASS FLARE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN MOSTLY QUIET TO UNSETTLED. WE ARE EXPECTING MINOR
GEOEFFECTIVNESS ON DAY 3 FROM TODAY'S LONG DURATION EVENT.
III.  EVENT PROBABILITIES 28 MAY-30 MAY
CLASS M    15/10/05
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           27 MAY 094
PREDICTED   28 MAY-30 MAY  094/094/096
90 DAY MEAN        27 MAY 108
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 26 MAY  007/008
ESTIMATED AFR/AP 27 MAY  008/010
PREDICTED AFR/AP 28 MAY-30 MAY  007/008-007/008-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 28 MAY-30 MAY
A.  MIDDLE LATITUDES
ACTIVE                10/10/20
MINOR STORM           01/01/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/15/25
MINOR STORM           05/05/10
MAJOR-SEVERE STORM    01/01/01