NOAA/USAF Report of Solar-Geophysical Activity 25 Mar 2000

::Product: Report of Solar-Geophysical Activity

Issued: 2000 Mar 25 2200 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 085 ISSUED AT 2200Z ON 25 MAR 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z

TO 25/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 8926 (S10W45) WAS THE

MOST ACTIVE REGION DURING THE PERIOD. THIS REGION PRODUCED SEVERAL

C-CLASS EVENTS, THE LARGEST BEING A C8/SF AT 25/0947UT. REGION 8926

DIMINISHED IN SIZE SLIGHTLY DURING THE DAY BUT ALSO DEVELOPED INTO A

MORE COMPLEX BETA-GAMMA MAGNETIC CLASSIFICATION. REGIONS 8924

(N10E41), 8925 (S18E50), AND 8928 (N19E45) WERE ALSO ACTIVE DURING

THE PERIOD PRODUCING ISOLATED OPTICAL SUBFLARES. THE REST OF THE

REGIONS WERE MOSTLY STABLE AND SHOWED VERY LITTLE ACTIVITY DURING

THE DAY. AN 20 DEGREE LONG, DISAPPEARING SOLAR FILAMENT (DSF) WAS

DETECTED NEAR S54E07.

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

MOSTLY LOW WITH THE POSSIBILITY OF ISOLATED M-CLASS EVENTS.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 24/2100Z TO 25/2100Z:

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

BEGAN TO DECREASE DURING THE PERIOD, INDICATING THAT THE EARTH IS

MOVING OUT OF THE  HIGH-SPEED CORONAL HOLE STREAM.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE QUIET TO UNSETTLED.

III.  EVENT PROBABILITIES 26 MAR-28 MAR

CLASS M    40/40/40

CLASS X    10/10/10

PROTON     05/05/05

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           25 MAR 205

PREDICTED   26 MAR-28 MAR  205/205/200

90 DAY MEAN        25 MAR 176

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 24 MAR  009/010

ESTIMATED AFR/AP 25 MAR  010/010

PREDICTED AFR/AP 26 MAR-28 MAR  010/012-008/010-008/010

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 MAR-28 MAR

A.  MIDDLE LATITUDES

ACTIVE                30/30/30

MINOR STORM           05/05/05

MAJOR-SEVERE STORM    01/01/01

B.  HIGH LATITUDES

ACTIVE                40/40/40

MINOR STORM           10/10/10

MAJOR-SEVERE STORM    01/01/01