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>Xref: infoac sci.astro:2579 rec.radio.amateur.misc:2908
>Path: infoac!unido!mcsun!uunet!lll-winken!aunro!alberta!cpsc.ucalgary.ca!yogi.hsc.ucalgary.ca!honte.uleth.ca!oler
>From: oler@honte.uleth.ca (Cary Oler)
>Newsgroups: sci.astro,rec.radio.amateur.misc
>Subject: SIGNIFICANT MAJOR FLARE ALERT - HIGH IMPACT EXPECTED
>Message-ID: <1991Jun6.053751.26945@honte.uleth.ca>
>Date: 6 Jun 91 05:37:51 GMT
>Organization: University of Lethbridge
>Lines: 58


                        --  MAJOR SOLAR FLARE ALERT  --

                                 JUNE 06, 1991

                              Flare Event Summary
                          Potential Impact Assessment


                                    --------



MAJOR ENERGETIC EVENT SUMMARY

     Region 6659 has spawned yet another very powerful solar flare.  This
event, like several of the other flares from this region, saturated the GOES
sensors at the class X12 level for between 20 and 25 minutes.  The true
intensity of this flare is unknown (it was well above a class X12 category).
The optical component was rated 3B.  A moderate intensity Type II and a major
Type IV sweep were observed with this event.  The flare began at 00:58 UT,
peaked at 01:08 UT and ended at 02:47 UT on 06 June.  A major HF blackout was
also observed with this event.


POTENTIAL TERRESTRIAL IMPACT ASSESSMENT

     A high terrestrial impact is expected from todays major flare.  Major to
severe geomagnetic storming is expected to occur in association with this
major event sometime early on 07 June.  A-indices of greater than 50 are
likely, with a risk for A-indices greater than 120 on 07 June.

     Protons are expected from this most recent flare.  A PCA event is also
anticipated, although the intensity of the PCA is not expected to be severe.
Proton levels are expected to reach 3,600 to 3,700 pfu.

     Auroral activity will continue at high to extremely high levels over the
next 24 to 72 hours.  These high levels of activity are expected to continue
as major flaring from Region 6659 continues.

     Major HF impacts, which have already been observed, will continue for
the next 24 to 72 hours.  As Region 6659 continues to move into progressively
more sensitive areas of the solar disk, the risk for increasingly intense PCA
activity will rise.  The next week to 10 days do not look good for HF radio
propagation conditions.  Major HF blackout conditions are possible over the
sunlit hemisphere during major flares.

     Conditions suitable for widespread VHF auroral backscatter will continue
over the next 12 hours, with a return to favorable conditions early in the UT
day of 07 June.  Significant levels of flutter and auroral-induced anomalies
will be observed throughout the next several days.

     Major flaring is expected to continue over the next 48 to 72 hours, at
least.  Projections estimate major proton flaring to be possible throughout
the next week.


**  End of Alert  **