Meteorology Name: ____________________ DRAWING FRONTS and the DEVELOPMENT of the MID-LATITUDE LOW

Let's practice trying to draw them. We may need to discuss the weather map symbols again. If so, we have a worksheet for that!

Draw in the Cold front and the Warm front. http://profhorn.meteor.wisc.edu/wxwise/wxpilot/lesson8/frontspractice.html Draw in the Cold front and the Warm front. http://profhorn.meteor.wisc.edu/wxwise/wxpilot/lesson8/frontspractice.html

Formation of Mid-Latitude Lows The polar front is the boundary between ________________ air masses in the polar easterlies and ______________ air masses in the prevailing westerlies. Polar air masses lie to the north of the ________________________. _________________________ air masses lie to the south of it. (sorry Brendon - different texts provide different explanations for this)

In the first stage, there is a _____________________________ in the These storms have a _____________________ -- they are not fixed in time and space; they ________________________ as they trek _____________________ (in our latitudes), almost as if you were holding a pinwheel and walking along with it. In the first stage, there is a _____________________________ in the _________________________ between the cold arctic/polar air and warmer tropical air.

A kink or wave frequently forms somewhere on the _______________________. There are many ways such a wave can form. One cause could be a wave or kink in the _______________. Another example could be if a cold air mass began moving __________________, pushing part of the polar front ahead of it. The wave moves from _____________________________, like a wave passing through a stage curtain shaken at one end. _______________________________________________________.

southward. This creates a southward moving __________________________. In the second stage, the front __________________________________ on the west side of the wave, where polar air pushes __________________________ southward. This creates a southward moving __________________________. On the east side of the wave, the polar front bulges _______________________ as a _______________________.

Between the cold and warm fronts is a large amount of ______________________________ air. The warm air bulges into and over the _________________________ air to form a region of ______________________. The _________________ pressure is at the __________________ of the wave where the ________________________________ meet. A low, or ________________, has formed.

The isobars around a low are roughly ______________________________, with a slight bend at the_______________________.

Winds whirl about the center of the low in a _____________________________ direction in the Northern Hemisphere.

The whole system moves eastward, but the cold front moves _____________________________ than the warm front. The front that forms when the cold front overtakes the warm front is called an ___________________________ front.

The warm air that had been stuck between the two colder airmasses is ____________________ completely off the surface in an occluded front. _______________________ continues until the low ___________________ and the two cold air masses mix across the ____________________ front.

A day or two after occlusion, the occluded front _______________________, the winds subside and a ______________________ front forms along the surface of the earth.

In summary, a low forms from a ____________ in a _______________________ front. To form a fully developed low takes only ______________________. Complete occlusion usually takes an additional _______________ or more.

As a low passes to the north of a locality in the Northern Hemisphere, the following weather changes occur: A long period of _____________________________ in advance of the ______________________. 2. _______________ and slow clearing after the warm front passes. If the air is humid, showery precipitation may occur, particularly nearer the __________________________. _____________________ precipitation around the time the _________________________ passes. 4. ______________________ and rapid clearing, with a change toward the weather characteristic of the newly arrived ___________________________. midlat_struct_mov.wmv

Don't think that these cyclones only strike the northern latitudes. December 13-14, an ___________________________________ (meaning one NOT in the tropics) dropped 2 feet of snow on El Paso, TX and surroundings.... ...paralyzing the city.

This storm was further fueled by cold _____________ air rising above the mountain areas bringing cold air over the mountains and causing the temperatures to fall below freezing. Additionally, the _____________________________ flow of the low pulled warm, moist air from the Gulf of Mexico and the Gulf of California high into the atmosphere.

Upper-Air Flow Throughout the life of a low-pressure system, __________________________ is what controls the surface low's _______________________________________. At the Earth's surface, air is constantly _______________________ into the low-pressure system. Instead of _______________________ the low, however, lows often strengthen over time.

The upper-air flow should explain this unexpected fact. If you look at a weather map, you will see that the upper-air flow is seldom _____________________. Instead, it curves back and forth like a winding road. _______________ are like traffic jams. As the air approaches, it crowds together and some air ________________ to the Earth's surface.