NOAA/USAF Report of Solar-Geophysical Activity 23 Mar 2000

:Product: Report of Solar-Geophysical Activity

:Issued: 2000 Mar 23 2230 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 083 ISSUED AT 2200Z ON 23 MAR 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  22/2100Z

TO 23/2100Z:  SOLAR ACTIVITY WAS MODERATE DUE TO TWO M-CLASS EVENTS

DURING THE PERIOD. THE FIRST WAS AN OPTICALLY UNCORRELATED M1 X-RAY

FLARE AT 23/0030UT AND THE SECOND WAS AN M2/SF FROM REGION 8910 AT

23/1214UT. REGION 8910 IS THE LARGEST AND MOST ACTIVE REGION AND CAN

BE EXPECTED TO CONTINUE TO PRODUCE C AND POSSIBLE M-CLASS

EVENTS AS IT APPROACHES THE WEST LIMB. REGIONS 8913 (S06W50), 8915

(N23W14), AND 8917 (N19W47) ALL PRODUCED C-CLASS FLARES DURING THE

PERIOD. REGIONS 8916 (N13E01), 8918 (N13W66), AND 8921 (S15E37) WERE

ALSO ACTIVE, PRODUCING OPTICAL SUBFLARES DURING THE REPORTING

PERIOD. FOUR NEW REGIONS WERE NUMBERED; 8924 (N13E70), 8925

(S17E76), 8926 (S10W18), AND 8927 (N18E01).

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

MODERATE.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 22/2100Z TO 23/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. THE SOLAR WIND SPEED

REMAINED HIGH, ALTHOUGH SHOWING A SLIGHT DECREASE DURING THE PERIOD,

FROM 600 TO 500 KM/S. PRESUMABLY RELATED TO A WELL POSITIONED

CORONAL HOLE IN THE SOUTHWEST.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE QUIET TO ACTIVE, WITH ISOLATED MINOR STORMING

CONDITIONS POSSIBLE AT HIGHER LATITUDES DURING THE SECOND DAY OF THE

PERIOD.

III.  EVENT PROBABILITIES 24 MAR-26 MAR

CLASS M    60/60/60

CLASS X    10/10/10

PROTON     10/10/10

PCAF       YELLOW

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           23 MAR 224

PREDICTED   24 MAR-26 MAR  230/240/245

90 DAY MEAN        23 MAR 175

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 22 MAR  008/011

ESTIMATED AFR/AP 23 MAR  015/015

PREDICTED AFR/AP 24 MAR-26 MAR  015/025-020/030-015/020

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 24 MAR-26 MAR

A.  MIDDLE LATITUDES

ACTIVE                50/60/50

MINOR STORM           10/10/10

MAJOR-SEVERE STORM    01/01/01

B.  HIGH LATITUDES

ACTIVE                60/70/60

MINOR STORM           20/25/20

MAJOR-SEVERE STORM    01/01/01