Low pressure systems
A low pressure system (cyclone) develops where relatively warm air ascends from the Earth's surface. These are systems of closed isobars surrounding a region of relatively low pressure.
: area of minimum air pressure, and cyclonic air movement.
LOW PRESSURE SYSTEM
An area of a relative pressure minimum that has converging winds and rotates in the same direction as the earth. This is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Low, s, Depression: opposite of high pressure system with the centre having the lowest pressure. Bulges and elongation in the circular pattern are known as Troughs of Low Pressure.
low (low pressure system): area with lower atmospheric pressure than its surrounding areas; this makes air from surrounding areas to flow into the low, the end result of which is probably cloudiness and precipitation.
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BOMB- A that decreases in central pressure by at least 24 millibars in a 24 hour period.
Low pressure systems that originate in the panhandle region of Texas and Oklahoma which initially move east and then "hook" or recurve more northeast toward the upper Midwest or Great Lakes region.
- A whirling mass of warm, moist air that generally brings stormy weather with strong winds. When viewed from above, winds spiral into a low-pressure center in a counterclockwise rotation in the Northern Hemisphere.
Deep low pressure systems can create a dome of water under the storm (much like the low pressure in a vacuum on a carpet).
When a draws near, altostratus clouds will appear at about 3 km in altitude. These types of clouds consist of a mix of ice crystals and water drops.
Surface low pressure systems will tend to be smaller in area and have stronger surface winds than a given high pressure system, due to the addition of surface friction to the pressure gradient force and coriolis effect that drive the circulation.
A strong that affects the Mid Atlantic and New England States. It can form over land or over the coastal waters.
A shallow low pressure system caused by the strong heating of the earth's surface. These lows are usually weak and are strongest in the late afternoon. They can trigger afternoon or evening showers and thunderstorms.
Heat wave ...
A that has its coldest temperatures at or near the center of circulation, and is thermally barotropic with respect to a horizontal plane. Also known as a cold core low.
Cold Low- a low pressure system with cold air mass from near the surface to all vertical levels (also called a cold core low).
Texas Hooker s that originate in the panhandle region of Texas and Oklahoma. The lows initially move east and then "hook" or recurve more northeast toward the upper Midwest or Great Lakes region.
WAVE CYCLONE - A low pressure system with waves and / or fronts associated with it. Wave cyclones are almost always extratropical type storms associated with frontal systems or upper level disturbances.
CLOSED LOW A that is completely encircled by an isobar. They often move slowly, as they displaced south of the main westerlies.
A general increase in the central pressure of a low pressure system.Fire WindA thermally driven wind blowing radially inward toward a fire, ...
Pancake IceIn hydrologic terms, circular flat pieces of ice with a raised rim; the shape and rim are due to repeated collisionsPanhandle HookLow pressure systems that originate in the panhandle region of Texas and Oklahoma which initially ...
Texas HookerSame as Panhandle Hook - low pressure systems that originate in the panhandle region of Texas and Oklahoma which initially move east and then "hook" or recurve more northeast toward the upper Midwest or Great Lakes region.
On your desk, repeat the hand twists for the High and models. Note the vertical motions of the palm of your hand.
Lake-Effect Snow Advisory: This product is issued by the National Weather Service when pure lake effect snow (this is where the snow is a direct result of lake effect snow and not because of a low pressure system) may pose a hazard or it is life ...
Cyclogenesis and Cyclolosis "Cyclogenesis" and "cyclolosis" are terms used by meteorologists to refer to stages of an extratropical cyclone or .
This index measures the anomalies in sea level pressure between the Icelandic low pressure system and the Azores high pressure system.
Snow Advisory- This product is issued when a produces snow that may cause significant inconveniences but do not meet warning criteria and if caution is not exercised could lead to life threatening situations.
Tropical cyclone is the name given to any low pressure system which is fueled by the heat released when moist air rises and condenses.
Subtropical cyclone: A that develops in subtropical waters (north of 20 north degrees latitude) and initially has non-tropical features (see table below for a list of tropical features) but does have some element of a tropical ...
Surface data indicates that a small scale low pressure system, about 100 miles in diameter, probably accounted for the LEWP configuration. Supercells often form near or immediately northeast of such a low.
FILLING Used in describing the history of a or an area of cyclonic circulation, it means an increase in the central pressure of the system.
A low pressure system that develops over subtropical waters that initially has a non-tropical circulation but in which some elements of tropical cyclone cloud structure are present. Subtropical cyclones can evolve into tropical cyclones.
The main difference, however, between a lake effect snow and a "standard" snow storm is that lake effect snow storms are not storms.
NOR' EASTER: An intense low pressure system that tracks along the east coast of the United States, producing strong northeast winds, large waves, and intense precipitation.
Cut-Off Low - An upper level that is no longer in the normal west to east upper air flow. Usually a cut-off low will lie to the South of the established upper air flow.
Tropical Storm - An organized low pressure system in the tropics with wind speeds between 38 and 74 mph.
Tropical Storm Warning- A warning issued when sustained winds of 39 to 73 mph (34 to 63 knots) are expected within 24 hours.
Subtropical Cyclone: A non-frontal that has characteristics of both tropical and extratropical cyclones.
Storm Track: The path followed by the centre of a low pressure system or cyclone over a given period of time, usually its lifetime.
JET STREAM: Strong winds concentrated within a narrow band in the atmosphere. The jet stream often "steers" surface features such as front and s.
KATABATIC WIND: Local winds a result of cold, dense air flowing downhill.
Dry Slot - A zone of dry (and relatively cloud-free) air which wraps east- or northeastward into the southern and eastern parts of a synoptic scale or mesoscale low pressure system. A dry slot generally is seen best on satellite photographs.
synoptic scale - Used with respect to weather systems ranging in size from several hundred kilometers to several thousand kilometers, the scale of migratory high and s (frontal cyclones) of the lower troposphere.
See also: Pressure, Low pressure, Low, Surface, Temperature