[Prev][Next][Index][Thread]

RE: (meteorobs) leonids

I think the only way to really know is to allow yourself at least 6-8
hrs before midnight of driving time in case the location you are at
looks washed out.  Close monitoring of Satellite cloud cover and
direction of travel will help immensely in determining where to go.
Last year that is what we did in Tulsa.  We watched the satellite and
determined Tulsa was going to be a wash out so the satellite showed
clearing skies toward Amarillo, Tex.  The next thing to do after you
locate an area, call that weather TV station in the city and explain
what you are going to be doing and most of the time they will be very
helpful and interested. We did that and got an all clear by midnight in
Amarillo and west.  The drive through Oklahoma and even to the east side
of Amarillo was clouded, but when we arrived in the city about 10p.m.,
the clouds starting disappearing and by Midnight we were under beautiful
clear skies.  And of course the storm was unbelievable, over 2,000
meteors from 3a.m.-6a.m.  So my advice would not be to count on
statistics entirely.  Watch the satellite, and allow yourself driving
time to get to where the clouds aren't.

David Stine
Comet-1

-----Original Message-----
From: H.Luethen [mailto:fb4a042@rzaixsrv2.rrz.uni-hamburgdot de] 
Sent: Thursday, May 09, 2002 1:03 AM
To: meteorobs@atmob.org
Subject: Re: (meteorobs) leonids

>I believe that the best place on the planet to
watch the 2002 Leonids will
>be in the American Southwest -- Arizona and New
Mexico. This is because the
>primary factor affecting observed rates is
weather. The probability of good
>clear weather in November in most of North
America -- except the Southwest
>-- is less than 50%. In the Southwest it's more
like 95%. The second factor
>is the altitude of the radiant at the time of the
peak. That favors the east
>coast.

My figures when analysing weather images from 1995
to 2001 supports
your impression. I looked at every weather picture
from Nov. 11
to Nov 22. in these years and estimated the
probability for seeing
the event at several sites. The figures indicate a
probability
of 81-83% for sites along the Mexican border.
The more you go to the North the lower the chances
are. Nevada, or Denver, have 60% probability, as
have sites
in the Midwest (e.g. Indiana). So high altitude
sites not
too far from the Mexican border seem to be best.

The following table gives the results (Clear sky
estimate in %, hr= radiant altitude at maximum in
degrees
hl=lunar altitude at maximum, twilight = beginning
of astr. twilight in UT, sun 18 deg below
horizon).
Expected maximum time is 10:29.

                 Clear skies %       hR  hl
twilight UT
Palomar            81                42  39
12:49
Kitt Peak          82
Puebla (Mexico)    85                55  23
11:26
Big Bend TX        83                54  28
11:54
Indiana            63                62  16
11:03
Denver             61                50  30
12:15
Nevada             57

Generally frontal systems cross the continent from
West to East, and the weather should be better the
more you go to
the south and the more you go to the east. There
are however
episodic invasions of clouds from the south,
especially
in El Nino years (eg 1997), and they are the
reason that sites
in Texas or even Mexico do not fare much better
than those
in southermost California. I don't know how much
fog can
affect weather in the east and Midwest. It appears
that
even in the east, the chances to see the event are
much
better than in central Europe. Note however that
the time
window shrinks dramatically from W to E.

Though going to the southwest appears to be a good
idea, one
still should search for internet access to be
alert, flexible and mobile
in case of clouds entering the region from the
south or southwest.

For a comparison: Last years Leonids, in a similar
analysis
gave around 60-70% for Australia, 80-85% for
Mongolia and NE
China, and 75% in Korea.


Hartwig








The archive and Web site for our list is at http://www.meteorobs.org
To stop getting all email from the 'meteorobs' lists, use our Webform:
http://www.meteorobs.org/subscribe.html
The archive and Web site for our list is at http://www.meteorobs.org
To stop getting all email from the 'meteorobs' lists, use our Webform:
http://www.meteorobs.org/subscribe.html