NOAA/USAF Report of Solar-Geophysical Activity 27 May 2000

Report of Solar-Geophysical Activity

:Issued: 2000 May 27 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 148 ISSUED AT 2200Z ON 27 MAY 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  26/2100Z

TO 27/2100Z:  SOLAR ACTIVITY WAS LOW. ONLY A FEW SMALL C-CLASS FLARES

OCCURRED.  THE MOST ACTIVE SUNSPOT GROUPS WERE REGIONS 9017 (S13E42)

AND 9018 (S21W24).  BOTH GROUPS HAVE GROWN BUT NEITHER HAS PRODUCED

SIGNIFICANT ACTIVITY. NEW REGION 9020 (N03E06) EMERGED.

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

TO MODERATE. C-CLASS ACTIVITY SHOULD CONTINUE AND THE POSSIBILITY OF

AN ISOLATED M-CLASS FLARE REMAINS.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. THE GREATER THAN 2 MEV

ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS MODERATE TO HIGH.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE QUIET TO UNSETTLED FOR THE FIRST DAY OR SO OF THE

FORECAST PERIOD. UNSETTLED TO ACTIVE CONDITIONS ARE POSSIBLE BY THE

THIRD DAY DUE TO CORONAL HOLE EFFECTS.

III.  EVENT PROBABILITIES 28 MAY-30 MAY

CLASS M    30/30/30

CLASS X    01/01/01

PROTON     01/01/01

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           27 MAY 162

PREDICTED   28 MAY-30 MAY  155/150/145

90 DAY MEAN        27 MAY 195

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 26 MAY  019/023

ESTIMATED AFR/AP 27 MAY  010/012

PREDICTED AFR/AP 28 MAY-30 MAY  010/015-012/025-015/018

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 28 MAY-30 MAY

A.  MIDDLE LATITUDES

ACTIVE                15/15/15

MINOR STORM           05/05/05

MAJOR-SEVERE STORM    01/01/05

B.  HIGH LATITUDES

ACTIVE                15/15/15

MINOR STORM           05/05/05

MAJOR-SEVERE STORM    05/05/05