Tornado Safety, Singing Frogs, and Other Spring Topics

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Singing frogs: the high-pitched chorus produced by Spring Peeper is one of the season's most familiar sounds.
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Diagram shows celestial objects you can expect to see in mid-April at about 40° north latitude, about 45 minutes after sunset.
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If you liv on the open prairie, a storm cellar is essential for tornado safety.
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Diagram shows late April celestial events at about 40° north latitude, about 45 minutes after sunset.  

If you’re looking for that wonderful thing called variety,
you certainly can find it in nature. And especially in
spring. Among our spring event topics in this column for April and May
are tornado safety, singing frogs, eclipses, and May
Day–the holiday that leads off the month of flowers.

Tornado Safety

Although May can bring us some of our most pleasant days,
it is also prime time in many parts of the Midwest for the
most violent of all atmospheric phenomena–the
tornado.

Tornado funnels range from tens of yards to about a mile
across. They may pass in a matter of seconds at forward
speeds of seldom more than 40 or 50 mph. But it is the
tremendous upward suction and especially the rotational
speeds of up to 300 mph that can be deadly.

There is much to say about these awesome storms, but I want
to focus here on safety. Many homes in tornado-prone parts
of the country have special storm shelters
underground–and that is the place to be when a
tornado is heading your way. Mobile homes are crumpled by
even small tornadoes. There’s an important tornado safety
precaution given in older books that needs to be corrected:
The southwest corner is not the safest place in
the house to be when a tornado, moving southwest to
northeast–as they most often do–hits the house.
The best advice is to put as many sturdy interior walls as
possible between you and the tornado and get down,
preferably underneath something that will protect you from
falling debris.

Good news is that the NEXRAD system of Doppler radar is in
the process of being installed around the United States.
These radar systems have already made it possible to give
people many more minutes’ worth of warning that a tornado
is about to descend from the clouds.

Singing Frogs

Before birds ever sang, there were Earth’s first singers:
the frogs. One of the most familiar choruses is the
high-pitched, long-carrying keening of the variety of tree
frogs known as Spring peepers.

Similar frogs are the West Coast’s pacific tree frog, the
Southwest’s color-changing canyon tree frog, and the
South’s green tree frog, squirrel tree frog, pine tree
frog, and whistling tree frog. But almost the entire
eastern half of the country is home to the common tree frog
and the spring peeper.

Spring peepers are very small (about 3/4 to 1 1/2″ long)
and distinguished from other frogs by the roughly X-shaped
dark markings on their backs. These tiny creatures use pads
on fingers and toes to cling to branches.

Actually, spring peepers begin their song before April and
May. They are noted as one of the first voices and
harbingers of spring. They can endure considerable cold. A
few hours before dawn on April 20, 1983, here in southern
New Jersey, I was out in a rare late snow–an inch or
more was on the ground–when I heard the strong song
of spring peepers. The temperature was 31° F.

Of May and May Day

After April, the ficklest month, comes sweet May. Weather
historian David Ludlum has suggested that this lovely month
should have been named Flora, after the Roman goddess of
flowers, rather than May, after Maia, another Roman goddess
of spring and fertility (actually Maia was originally a
Greek goddess).

The halfway point of spring falls on May 6, though in the
northern United States and southern Canada, frosts and
chilly weather are not uncommon early in the month. So it
is not fair to say that the entire month is abloom
everywhere. Memorial Day was put at the end of May to make
sure that even in the northernmost United States there
would be plenty of flowers to lay on graves of fallen
soldiers.

As usual, it is not quite at the mathematically accurate
halfway point of a season that the “cross-quarter day” gets
celebrated. In spring, the cross-quarter holiday is May
Day, the first of May, a day of merriment and many innocent
and sweet traditions. Some are now little remembered: for
instance, the custom of having maidens wash their face with
May dew gathered at dawn on May Day to assure beauty.

The dance around the Maypole and the selection of a May
Queen are traditions of old England that even flourished in
parts of the United States until early this century.
Another delightful tradition that has survived to the
present (in my wife’s family, for one!) is the custom of
children rising early to gather wildflowers and secretly
leaving them on the doorstep of a friend, neighbor, or
mother. They knock, run, hide, and watch!

Of course, long ago, the first of May was also the occasion
for the dark revelries and human sacrifices of the Celtic
holiday Beltane, fire of the god Bel. This occurred halfway
through the Druidic year that began on Samhain, the
predecessor of Halloween. Whereas Samhain marked the
beginning of the year at its low point in the cycle of the
living world, Beltane marked the middle of the year when
growth was at its strongest.

Observe the Big Solar
Eclipse–Safely!

April and May are particularly interesting months in
astronomy this year, with April’s conjunctions of moon and
planet and May’s two eclipses.

The lunar eclipse on the night of May 24 is a small partial
one; the moon goes only one-quarter of the way into the
umbra, or central shadow of the Earth. The slight staining
you’ll see on the lower edge of the moon before it enters
the umbra is caused by the penumbra, or outer shadow, of
Earth. Even such a small eclipse is fascinating to watch.
If you have a telescope, see if there is, at any stage,
color to part of the umbra or its edge.

The really exciting eclipse of May is an America-wide solar
eclipse, the deepest visible for the 48 states as a whole
until several decades from now. You MUST NOT look at the
sun during this eclipse without proper eye protection, but
I’ll discuss in a moment what kind of protection and
observing techniques are safe.

First, let’s consider what kind of eclipse this will be.
For most of the country, the eclipse will be a large
partial one; most of the sun will be hidden. If you live in
Alaska, you’ll see a small partial solar eclipse, but in
Hawaii none at all. A wide diagonal strip of land from the
Southwest to southern Maine will be treated to more than
just an ordinary partial eclipse; it will be treated to an
annular solar eclipse.

Annular means “ring-shaped.” In such an eclipse the moon
passes centrally in front of the sun but is out too far in
its orbit to appear large enough to hide the sun’s entire
disk. A ring of sunlight shines out from around the moon’s
silhouetted form. When the moon is close enough to earth
during a central eclipse, the eclipse is total–all
the sun’s fiery disk is hidden and magnificent sights like
the sun’s pearly outer atmosphere appear in a sky dark
enough for some stars to come out. At an annular eclipse
you don’t get to see grandeur as stunning as that of a
total eclipse. But you do get to see a rather impressive
darkening of sky and landscape, change in the color of
sunlight, weird shadows on the ground, and more.

But what about getting a sight of the sun’s disk itself
during the eclipse? During a partial or annular eclipse,
you should never look at the sun unless you use
proper protection for your eyes. You can look through
shade, such as a suitably large piece of welder’s glass
that can be bought for about $2 or less from your local
welding supply store, but only with the eyes, not with
binoculars or telescope. Many small telescopes come with
solar filters, but often they are poorly made. Seek out
your local planetarium or astronomy club for safe
telescopic views, unless you want to use a perfectly safe
alternative and try projection with your telescope or
binoculars.

All you do in projection is put the sun at your back and
then–being careful not to ever look into the
telescope or binoculars–maneuver your optical
instrument until its tube (or tubes) is casting the
smallest possible shadow. The sun should now be shining
into your instrument and the magnified solar image can be
projected onto a screen–say, a piece of cardboard. But be
careful, the eyepiece of a telescope can focus great heat
in front of it. On your screen you will see a disk of light
(focus the optical instrument or adjust the screen’s
distance to make that disk sharp-edged), possibly with some
curious black speckles here and there on it. What you see
is the sun, with various dark looking sunspots.

By the way, even if you have no binoculars or telescope,
you can project the image of the solar eclipse with
something as simple as a piece of cardboard with a pinhole
in it. The image projected onto a second piece of cardboard
will be tiny, but you should be able to see an ever-larger
bite taken out of it as the moon moves across the sun.


Lunar Eclipse Timetable

For Partial Lunar Eclipse of May 24-25
(in Eastern Daylight Time)

10 P.M. EDT (May 24): First traces of penumbral shading
visible around now?
10:37 P.M. EDT: Umbra first touches moon (before sunset and
moonrise on West Coast).
11:30 P.M. EDT: Mideclipse.
12:23 A.M. EDT (May 25): Umbra last touches moon.
1 A.m. EDT: Last trace of penumbral shading visible around
now?


Time of Maximum Eclipse for
Annular Solar Eclipse of May 10

The time of maximum eclipse ranges from about 9 A.M. PDT
for California to almost 2 P.M. EDT for Maine. Some of the cities the eclipse will appear annular from
(the Sun covering up to 93% of the sun’s diameter): El
Paso, Amarillo, St. Louis, Springfield (Illinois), Detroit,
Toledo, Buffalo, Toronto. The cities of Kansas City and
Chicago are just outside the zone of annular eclipse.


Almanac for April and May 1994

April

1. Good Friday; April Fool’s Day.
2. Last Quarter Moon, 9:55 P.M. EST.
3. Faster; Daylight Saving Time begins.
10. New Moon, 8:18 Par. EDT
11. Young Moon–very thin crescent just after sunset,
low, just north of due west; Farthest Moon of the year
(252,568 miles from Earth).
12. Very close Moon–Venus conjunction around land
after) sunset.
13. Thomas Jefferson’s birthday (1843).
15. 76 inches of snow fell in Silver Like, Colorado, in 24
hours (1921).
16. Astronomy Day.
18. First Quarter Moon, 10:34 P .M. EDT Sun enters
constellation Aries.
19. Lexington-Concord Day (1775).
20. Sun enters astrological sign Taurus; Earth Day.
24. Very close Moon–Spica conjunction this
evening.
25. Full Moon (Pink Moon, Sprouting Grass Moon, Egg Moon,
Fish Moon), 3:45 P.M. EDT; Closest Moon of the year
(221,785 miles from Earth) just a few hours earlier (so
very high tides); Moon-Jupiter conjunction this
evening.
29. Arbor Day (except in Alaska, Georgia, Kansas, Virginia,
and Wyoming).
30. May Eve; Jupiter at opposition with the Sun.

May
1. May Day, Beltane.
2. Last Quarter Moon, 10:33 PM. EDT.
6. Halfway point of springy Omaha torna do killed 3, caused
$150 million damage (1975).
8. Mother’s Day.
10. Annular eclipse of the Sun across U.S.; New Moon, 1:07
P.M. EDT.
13. Friday the 13th (only one of 1994); Sun enters
constellation Taurus.
17. Pluto at opposition with the Sun.
18. Fast Quarter Moon, 8:49 A.M.. EDT.
19. Dark Day in New England, 1780 (caused by western forest
fires).
21 Armed Forces Day; Sun enters astroIogical sign
Gemini.
22. Whit Sunday (Pentecost).
23. Victoria Day (Canada).
24. Partial eclipse of the Moon; Full Moon (Flower Moon,
Corn Planting Moon, Milk Moon), 11:39 P.M. EDT.
26. Mercury closest to Venus in evening sky (about 9°
apart).
29. Venus very near a star in Gemini.
30. Memorial Day (observed); Mercury at greatest evening
elongation.