FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 348
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 13 DEC 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 12/2100Z
TO 13/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 5278 (N25E66)
PRODUCED AN M2/SF FLARE AT 0218Z WHICH WAS ACCOMPANIED BY A
STRONG TYPE II SWEEP. THIS REGION PRODUCED SURGING ALL DAY
AS MORE SPOTS CONTINUED TO ROTATE INTO VIEW: THE AVERAGE
AREAL COVERAGE IS NOW 750 MILLIONTHS. REGIONS 5275 (S33E30),
5265 (N20W47), AND 5269 (N32W11) ALSO CONTRIBUTED SMALL FLARES.
NEW REGION 5279 (N21E39) EMERGED DURING THE PERIOD. THE
REMAINDER OF THE DISK AND LIMBS WERE STABLE.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE. REGION 5278 IS CONSIDERED TO BE THE PRIMARY THREAT
FOR M-CLASS OR GREATER FLARES. THERE CONTINUES TO BE A SLIGHT
CHANCE FOR SUCH ACTIVITY FROM REGIONS 5275 AND 5273.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 12/2100Z TO 13/2100Z:
THE GEOMAGNETIC FIELD WAS GENERALLY UNSETTLED TO ACTIVE, WITH
SOME ISOLATED PERIODS OF MINOR STORM CONDITIONS AT HIGH
LATITUDES, PARTICULARLY IN THE LATTER PART OF THE DAY. THE
DISTURBANCE MAY HAVE BEEN CAUSED BY EITHER THE LONG DURATION
M2 FLARE THAT OCCURRED ON 10 DECEMBER, OR BY A FILAMENT THAT
ERUPTED FROM THE DISK BETWEEN 09 AND 10 DECEMBER.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE PREDOMINANTLY UNSETTLED FOR THE NEXT THREE DAYS.
ISOLATED PERIODS OF ACTIVE CONDITIONS MAY PERSIST AT HIGHER
LATITUDES TOMORROW.
III.  EVENT PROBABILITIES 14 DEC-16 DEC
CLASS M    65/65/65
CLASS X    15/15/15
PROTON     15/15/15
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           13 DEC  186
PREDICTED   14 DEC-16 DEC  188/190/190
90 DAY MEAN        13 DEC  163
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 12 DEC  011/012
ESTIMATED AFR/AP 13 DEC  015/018
PREDICTED AFR/AP 14 DEC-16 DEC  012/015-012/012-010/009