FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 286
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 12 OCT 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 11/2100Z
TO 12/2100Z:  SOLAR ACTIVITY HAS BEEN HIGH. REGION 5175 (S16W73)
PRODUCED AN X2/2N FLARE AT 12/0511Z. THE FLARE WAS ACCOMPANIED
BY A 490 SFU DISCRETE FREQUENCY BURST AT 2695 MHZ (AS WELL AS
OTHER BURSTS ACROSS THE SPECTRUM), AN ERUPTIVE PROMINENCE AND
BRIGHT SURGE NEAR THE LIMB, AND A TYPE IV SWEEP FREQUENCY
BURST. THE REGION ALSO PRODUCED AN M1 X-RAY BURST AT 12/1212Z.
NO SIGNIFICANT RADIO EMMISSIONS WERE ASSOCIATED WITH THE EVENT.
LITTLE OR NO ACTIVITY WAS OBSERVED FROM THE OTHER REGIONS. FOUR
NEW REGIONS WERE ASSIGNED TODAY: 5189 (N25E35), 5190 (S20E13),
5191 (S23E28), AND 5192 (N19E58). REGION 5192 WAS FORMERLY THE
TRAILER PORTION OF REGION 5188.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
LOW TO MODERATE. THERE IS A FAIR CHANCE FOR M-CLASS FLARES
AND A VERY SLIGHT CHANCE FOR AN X-CLASS FLARE FROM REGION 5175.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 11/2100Z TO 12/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN AT QUIET TO UNSETTLED
LEVELS FOR THE PAST 24 HOURS AT MIDDLE LATITUDES. THE HIGH
LATITUDE FIELD HAS BEEN AT UNSETTLED TO ACTIVE LEVELS. A
MINOR PROTON EVENT OCCURRED IN THE WAKE OF TODAY'S X-CLASS
FLARE: IT BEGAN AT 12/0920Z, REACHED A MAXIMUM OF 12 PFU
(P CM-2 S-1 SR-1) AT 12/0930Z, AND ENDED AT 12/0945Z. NO
SIGNIFICANT POLAR CAP ABSORPTION EVENT OCCURRED IN
CONJUNCTION WITH THE PROTON EVENT (MAXIMUM RECORDED
ABSORPTION WAS .6 DB AT 12/1212Z).
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT UNSETTLED TO MINOR STORM LEVELS AT MIDDLE
LATITUDES. THE HIGH LATITUDE FIELD IS EXPECTED TO BE AT ACTIVE
TO MINOR STORM LEVELS. THE MINOR STORM CONDITIONS ARE EXPECTED
IN RESPONSE TO TODAY'S X-CLASS FLARE.
III.  EVENT PROBABILITIES 13 OCT-15 OCT
CLASS M    40/40/30
CLASS X    10/10/05
PROTON     10/10/05
PCAF       YELLOW
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           12 OCT  149
PREDICTED   13 OCT-15 OCT  144/140/138
90 DAY MEAN        12 OCT  157
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 11 OCT  013/027
ESTIMATED AFR/AP 12 OCT  007/022
PREDICTED AFR/AP 13 OCT-15 OCT  012/020-030/030-020/040