NOAA/USAF Report of Solar-Geophysical Activity 4 March

:Product: Report of Solar-Geophysical Activity

:Issued: 2000 Mar 04 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 064 ISSUED AT 2200Z ON 04 MAR 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  03/2100Z

TO 04/2100Z:  SOLAR ACTIVITY HAS BEEN LOW FOR THE PAST 24 HOURS.

REGION 8882 (S15W83) PRODUCED TODAY’S LARGEST EVENT, A C6/SF AT

03/2345Z. TWO NEW SUNSPOT GROUPS EMERGED: REGION 8899 (S11E19) AND

REGION 8900 (S15E16). REGION 8900 SHOWED STEADY GROWTH AND PRODUCED

OCCASIONAL SUBFLARES. THE GROUP DEVELOPED INTO A SMALL, D-TYPE

REGION BY THE END OF THE REPORTING PERIOD. REGION 8891 (S15W29) IS

STILL THE LARGEST GROUP ON THE DISK BUT SHOWED SIGNS OF DECAY AND

WEAKENING MAGNETIC FIELDS. AN 11 DEGREE FILAMENT NEAR N40W36

DISAPPEARED BETWEEN 0804-0900Z. X-RAY IMAGES FROM THE YOHKOH

SPACECRAFT SHOWED AN ENHANCED LOOP SYSTEM FORMED IN ASSOCIATION WITH

THE DISAPPEARANCE, SUGGESTING THAT A CME OCCURRED. ANOTHER 15 DEGREE

FILAMENT NEAR S35E50 DISAPPEARED AT ABOUT 1800Z. THIS DISAPPEARANCE

WAS FOLLOWED BY PARALLEL H-ALPHA RIBBONS, A WEAK X-RAY ENHANCEMENT,

A WEAK TYPE II SWEEP, AND A FAINT CME SIGNATURE AS OBSERVED BY THE

MAUNA LOA CORONAGRAPH, ALL OF WHICH INDICATE ERUPTION OF THE

FILAMENT.

IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW

TO MODERATE. A GRADUAL DOWNWARD TREND IN ACTIVITY IS EXPECTED WITH

THE DEPARTURE OF REGIONS 8886 AND 8882 OVER THE NEXT THREE DAYS.

THERE REMAINS A SLIGHT CHANCE FOR A MAJOR FLARE EVENT. REGION 8891

CONTINUES TO BE THE MAIN THREAT FOR AN ISOLATED MAJOR EVENT.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 03/2100Z TO 04/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND OBSERVATIONS

AT THE L1 POINT GAVE NO INDICATION OF RECENT FLARE-ASSOCIATED

CORONAL MASS EJECTION ACTIVITY.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE UNSETTLED TOMORROW, WITH A POSSIBILITY FOR SOME

ACTIVE PERIODS. PREDOMINANTLY UNSETTLED LEVELS SHOULD FOLLOW ON THE

SECOND DAY, AND CONDITIONS SHOULD BE QUIET TO UNSETTLED ON THE THIRD

DAY. THERE IS A SLIGHT, BUT DECREASING POSSIBILITY THAT A GLANCING

BLOW FROM CME ACTIVITY OF 2 MARCH WILL BE SEEN OVER THE NEXT 24

HOURS.

III.  EVENT PROBABILITIES 05 MAR-07 MAR

CLASS M    45/45/40

CLASS X    15/10/05

PROTON     20/15/10

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           04 MAR 200

PREDICTED   05 MAR-07 MAR  195/190/190

90 DAY MEAN        04 MAR 170

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 03 MAR  005/005

ESTIMATED AFR/AP 04 MAR  005/005

PREDICTED AFR/AP 05 MAR-07 MAR  015/018-010/015-005/010

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 05 MAR-07 MAR

A.  MIDDLE LATITUDES

ACTIVE                25/20/15

MINOR STORM           15/10/05

MAJOR-SEVERE STORM    05/05/05

B.  HIGH LATITUDES

ACTIVE                30/25/20

MINOR STORM           15/10/10

MAJOR-SEVERE STORM    05/05/05