NOAA/USAF Report of Solar-Geophysical Activity 12 July 2000

:Product: Report of Solar-Geophysical Activity

:Issued: 2000 Jul 12 2210 UT

# 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 194 ISSUED AT 2200Z ON 12 JUL 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  11/2100Z

TO 12/2100Z:  SOLAR ACTIVITY WAS HIGH. REGION 9077 (N17E16) PRODUCED

THE FIRST OF SEVERAL SIGNIFICANT EVENTS FOR THE PERIOD. IT PRODUCED

AN M1/1N AT 12/0502Z WITH MINOR CENTIMETRIC BURSTS. THIS WAS

FOLLOWED BY AN X1/2B AT 12/1037Z WITH AN ASSOCIATED 390 SFU TENFLARE

AND TYPE IV RADIO SWEEP. REGION 9070 (N19W63) PRODUCED AN M1/SF AT

12/1655Z. REGION 9077 PRODUCED ANOTHER MAJOR FLARE AT 12/1849Z,

AN M5/2F WITH AN ASSOCIATED 230 SFU TENFLARE. AN OPTICALLY

UNCORRELATED TYPE II RADIO SWEEP OCCURRED AT 12/2014Z. BOTH REGIONS

9070 AND 9077 MAINTAIN COMPLEX MAGNETIC DELTA CONFIGURATIONS.  AN

IMPRESSIVE CME WAS OBSERVED AROUND 12/0200Z FROM A REGION ON OR

BEHIND THE SOUTHEAST LIMB OF THE SUN.

IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO REMAIN

AT HIGH LEVELS. EXPECT FREQUENT C-CLASS FLARES WITH AN ISOLATED

CHANCE FOR A MAJOR FLARE FROM REGION 9070. REGION 9077 WILL LIKELY

CONTINUE TO PRODUCE MAJOR FLARES.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 11/2100Z TO 12/2100Z:

THE GEOMAGNETIC FIELD WAS AT QUIET TO MINOR STORM LEVELS. MINOR

STORMING WAS OBSERVED EARLY IN THE PERIOD AS YESTERDAY’S DISTURBANCE

SUBSIDED. MOSTLY MINOR TO UNSETTLED CONDITIONS WERE OBSERVED FOR THE

REMAINDER OF THE PERIOD. THE GREATER THAN 10 MEV PROTONS REMAIN

ENHANCED BUT HAVE NOT YET CROSSED ALERT THRESHOLD.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BEGIN THE PERIOD AT QUIET TO ACTIVE CONDITIONS. MINOR TO

MAJOR STORM CONDITIONS ARE EXPECTED TO DEVELOP LATE ON DAY ONE AS A

RESULT OF CME’S OBSERVED ON 10-11 JULY. CONDITIONS ARE EXPECTED TO

RETURN TO UNSETTLED TO ACTIVE LEVELS ON DAY THREE OF THE FORECAST

PERIOD. THE GREATER THAN 10 MEV PROTONS FLUX ARE STILL EXPECTED TO

CROSS EVENT THRESHOLD DURING THE PERIOD.

III.  EVENT PROBABILITIES 13 JUL-15 JUL

CLASS M    90/90/90

CLASS X    50/50/50

PROTON     20/20/20

PCAF       YELLOW

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           12 JUL 230

PREDICTED   13 JUL-15 JUL  225/220/200

90 DAY MEAN        12 JUL 183

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 11 JUL  031/031

ESTIMATED AFR/AP 12 JUL  015/018

PREDICTED AFR/AP 13 JUL-15 JUL  025/025-050/050-015/020

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 13 JUL-15 JUL

A.  MIDDLE LATITUDES

ACTIVE                15/20/15

MINOR STORM           25/40/10

MAJOR-SEVERE STORM    30/40/07

B.  HIGH LATITUDES

ACTIVE                20/20/20

MINOR STORM           30/40/15

MAJOR-SEVERE STORM    40/40/10