:Product: 19980806RSGA.txt
:Issued: 1998 Aug 06 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 218 ISSUED AT 2200Z ON 06 AUG 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  05/2100Z
TO 06/2100Z:  SOLAR ACTIVITY WAS LOW. REGIONS 8293 (S22E22) AND 8296
(N17E58) PRODUCED MOST OF THE PERIOD'S FLARES, THE LARGEST BEING IN THE
LOW C-CLASS RANGE. THE DAY'S MOST SPECTACULAR ACTIVITY OCCURRED NEAR
N14 AT EAST LIMB WHERE A SPRAY WAS OBSERVED AT APPROXIMATELY 1605Z.
THIS EVENT MEASURED C-2 IN X-RAYS, AND INCLUDED TYPES II AND IV
SWEEP. ADDITIONAL SURGING WAS SEEN NEAR N26E90, MAKING PERHAPS TWO
NEW REGIONS COMING INTO VIEW. ONE NEW REGION, 8297 (N30E73) APPEARED
AS A SINGLE MATURE SPOT.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
HOWEVER, CONTINUED DEVELOPMENT IN REGION 8293 MAY RESULT IN AN
ISOLATED M-CLASS EVENT IN THE NEXT 3 DAYS. THIS REGION NOW SHOWS A
BETA-GAMMA DELTA MAGNETIC CONFIGURATION AND MAY PRODUCE MAJOR FLARES
IF THESE GRADIENTS STRENGTHEN. IN ADDITION, EAST LIMB MAY PROVIDE
OCCASIONAL C-CLASS EVENTS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 05/2100Z TO 06/2100Z:
THE GEOMAGNETIC FIELD WAS AT QUIET TO STORM LEVELS THROUGHOUT THE
PERIOD. A TRANSIENT STRUCTURE WAS SEEN TO PASS ACE BEGINNING AT
APPROXIMATELY 0644Z. THE MASS EJECTION WAS CHARACTERIZED BY ENHANCED
SOUTHWARD BZ OF APPROXIMATELY -20 NT FOR A FEW HOURS TO FOLLOW. A
WEAK SUDDEN IMPULSE WAS OBSERVED IN THE EUROPEAN SECTOR AT 0736Z,
AND SEVERE STORM CONDITIONS FOLLOWED SHORTLY THEREAFTER. K INDICES
OF 8 AND 9 WERE REPORTED AT HIGH LATITUDES AND SLIGHTLY LESSER
VALUES WERE SEEN AT MIDDLE LATITUDES. THE MAIN DISTURBANCE WANED BY
1800Z TO QUIET CONDITIONS AT BOULDER. THIS CME MAY BE RELATED TO
SOLAR ACTIVITY WITH TYPES II AND IV SWEEP IN THE EARLY HOURS OF
AUGUST 1.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT UNSETTLED TO MINOR STORM LEVELS FOR THE NEXT 24
HOURS AS THE CURRENT DISTURBANCE WEAKENS. EPISODES OF MINOR TO MAJOR
STORMING ARE POSSIBLE DURING LOCAL NIGHTTIME HOURS FOR THE NEXT DAY.
QUIET TO UNSETTLED CONDITIONS SHOULD END THE PERIOD.
III.  EVENT PROBABILITIES 07 AUG-09 AUG
CLASS M    25/25/25
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           06 AUG 138
PREDICTED   07 AUG-09 AUG  145/150/150
90 DAY MEAN        06 AUG 109
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 05 AUG  006/009
ESTIMATED AFR/AP 06 AUG  040/070
PREDICTED AFR/AP 07 AUG-09 AUG  015/030-005/018-005/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 07 AUG-09 AUG
A.  MIDDLE LATITUDES
ACTIVE                30/20/05
MINOR STORM           30/10/05
MAJOR-SEVERE STORM    10/01/01
B.  HIGH LATITUDES
ACTIVE                40/30/20
MINOR STORM           40/20/10
MAJOR-SEVERE STORM    15/05/01