Download Klaus Austin V. Fuentes NatSci-A7 Jan Michael Gaite Submitted to

Klaus Austin V. Fuentes
Jan Michael Gaite
NatSci-A7
Submitted to: Ms. Ivy Claire Mordeno
WEATHER DISTURBANCE – a general term that describes any pulse of energy moving
through the atmosphere. They are important in that they can act as focusing mechanisms
for storm formation, or even to intensify low pressure systems. To be more technical, they are
typically mid or upper atmospheric troughs of low pressure that are embedded in the general
wind flow of the atmosphere.
TYPES:
1. TYPHOON
A large heat engine, where great amounts of heat are being produced from the
process of latent heat of condensation. This occurs as water vapor is being
evaporated from the ocean surface and condensed into cloud droplets.
CAUSES:
1. Pre-existing Disturbance or low pressure area must have formed in the low
levels of the atmosphere to start winds converging and uplift.
2. Warm Water to a sufficient depth to support the energy that a hurricane will
need. The temperature needs to be about 26.5º Celsius or 80º Fahrenheit to a
depth of about 50 meters or 150 feet deep.
3.
Low Stability will allow deep convection or cumulonimbus clouds to build to
great heights in the atmosphere. A stable air mass will inhibit cloud development
and not allow for significant cloud growth to support the deep convection needed
for a hurricane to develop.
4. Coriolis Force The disturbed area of weather needs to be at least 4-5º away
from the equator. This is the approximate distance from the equator for the
Coriolis force to achieve a gradient wind balance to sustain the low pressure
area.
5. Moist Mid Level of the atmosphere. If there is dry air aloft it will weaken or choke
off the updrafts in the cumulus clouds.
6.
Low Vertical Wind Shear from the surface to upper troposphere. This allows for
the thunderstorm clouds to build to great heights. If the wind speed increases or
changes direction with height, the cumulonimbus clouds get deformed can not
sustain the hurricane heat engine.
7. Divergence in the upper Atmosphere allows for the transport of mass away
from the hurricane.
2. TROPICAL CYCLONE
a storm
system characterized
by
a low-pressure center
numerous thunderstorms that produce strong winds and heavy rain.
and
CAUSES:
1.
2.
3.
4.
5.
6.
Water temperatures of at least 26.5 °C (79.7 °F) are needed down to a
depth of at least 50 m (160 ft); waters of this temperature cause the
overlying atmosphere to be unstable enough to sustain convection and
thunderstorms.
Rapid cooling with height, which allows the release of the heat of
condensation that powers a tropical cyclone.
High humidity is needed, especially in the lower-to-mid troposphere; when
there is a great deal of moisture in the atmosphere, conditions are more
favorable for disturbances to develop.
Low amounts of wind shear are needed, as high shear is disruptive to the
storm's circulation.
Tropical cyclones generally need to form more than 555 km (345 mi) or
5 degrees of latitude away from the equator, allowing the Coriolis
effect to deflect winds blowing towards the low pressure center and creating
a circulation.
Formative tropical cyclone needs a pre-existing system of disturbed
weather, although without a circulation no cyclonic development will take
place.
3. TORNADO
is a violently rotating columns of air usually produced by severe thunderstorms. In
appearance they are generally funnel shaped but may also have the likeness of a
rope (skinny tornado) or wedge (very wide tornado). There can be several mini
tornadoes circulating around a larger one. These are called multi vortex tornadoes
and are usually violent. Some tornadoes form over water and these are called
waterspouts. Most waterspouts form from high instability of growing convective
clouds over water. Landspouts are similar to waterspouts as are not associated with
a thunderstorm mesocyclone.
HOW TORNADOES ARE FORMED:
-
Tornadoes form in generally strong wind shear conditions. This is observed as winds
increase in speed and change direction (veer) with increasing altitude. Invisible
horizontal tubes of sinning air are created by this process. As thunderstorms form,
these tubes are tilted vertically. Thunderstorms start to rotate with diameters ranging
from 2-6miles. If the rotation is strong enough, a wall cloud develops. This is a cloud
that rotates, hanging low under the updraft of the thunderstorm. If a burst of air drops
from a nearby downdraft – it may enter the strong updraft under the wall cloud. The
column of air is stretched and a tornado is formed. In this sense, most tornadoes
actually form from the ground up. It is simply highly saturated air dropping from the
thunderstorm which gives the appearance of a tornado “touching down”.
How fast do tornadoes move?
- A tornado on average moves at speeds of 30mph, but can range stationary to about
70mph.