Chapter 4 Investigation A

The temperature at Dallas, TX, (south of the TX-OK border low center), was 52°F with winds from the south. The isotherm line plotted near Dallas was the ________ degree Fahrenheit isotherm.

50

Areas to the east of Highs would be expected to have ______ air advection.

cold

Not all data, especially on operational maps, are always accurate as instrumental and communications errors occur occasionally. There is likely a spurious data point in this analysis of Figure 3. Southeast of Texas in the Gulf of Mexico, multiple concentric rings of isotherms surround an area of ________ temperatures. This point is likely an error because of the warm, broad air mass in the region with weak or calm winds in the vicinity.

lower

Where the horizontal wind blows parallel to isotherms, there is ______ air advection.

neither cold or warm

Your temperature analysis reveals a pattern with coldest temperatures located to the ______ portion of the map.

north-central

The wind at Dallas exhibited a flow that was directed at an angle nearly perpendicular to that isotherm. This wind direction was from ________ temperature regions.

higher toward lower

The wind at Atlanta exhibited a flow that was oriented almost directly across the isotherms. This wind direction was from ________ temperature regions. Stations from the East Coast to Nebraska that were north of the frontal system generally displayed this same pattern of temperatures and air flow directions.

lower to higher

The wind at Des Moines exhibited a flow that was oriented almost perpendicular to the isotherm. This wind direction was from ________ temperature regions.

lower toward higher

From the TX-OK border Low, the same front curved generally westward to northern New Mexico. From northeastern New Mexico, a(n) ________ front continued generally north-south along the Rocky Mountains, where cold air could not advance westward.

stationary

Air temperatures are governed by a combination of warm or cold air advection and radiational controls. With no advection, the lowest temperature of the day is likely to occur around ______.

sunrise

Stations that were experiencing this northerly wind flow (e.g., Iowa, Minnesota, and Kansas) were all found ________ the prominent cold front in Figure 3.

to the west of

And behind warm fronts one can expect ______ air advection.

warm

And while not shown here but relying on the hand-twist model of a High, areas to the west of Highs should have ______ air advection.

warm

Generalizing from this map depiction of wind and temperature patterns associated with weather systems, areas southeast of Lows can be expected to have ______ air advection.

warm

If a day's highest temperature actually occurs just before midnight, then ______ air advection likely occurred sometime from late afternoon until the time of highest temperature.

warm

This flow of air at Dallas was in an area of ________ air advection. Figures 3 and 4 show that both types of air advection patterns are often found on weather maps regardless of the time of year.

warm

Isotherms are drawn at regular intervals; on this map, the interval between successive isotherms is ______ Fahrenheit degrees.

10

The wind at Atlanta, in northwest Georgia, was generally from the north-northwest at about 10 knots. Atlanta was located between the ________ -degree isotherm lines (labelled in eastern Colorado.

20 and 30

The wind at Des Moines, in central Iowa, was generally from the north at about 10 knots. The isotherm line plotted just northwest of Des Moines was the ________ -degree Fahrenheit isotherm. (The value is marked along the line in southeast Minnesota.)

50

Figure 2 displays a surface weather map of the contiguous U.S. for a different time that shows a simplified view of a storm system in the eastern part of the country. Local wind data are displayed for several stations and three isotherms have been drawn on the map. The isotherm values (from lowest to highest) are ______°F.

50, 60, 70

The eastern third of the country displayed temperatures at map time generally in the ________ degrees Fahrenheit.

60s and 70s

Cold air advection was occurring at Station ______.

B

Warm air advection was occurring at Station ______.

D

And in addition, this same type of air temperature advection was displayed with the broad-scale circulation pattern to the eastern and southern sides of the ________.

Lake Superior High

This type of air temperature advection was also displayed with the circulation pattern to the western side of the ________.

New England Low

From the eastern Low, a(n) ________ front curved generally southward and then westward across the Southeastern states.

cold

From this wind flow pattern, one can conclude that ________ air advection was occurring. This flow dominated the majority of the eastern half of the country.

cold

From this wind flow pattern, one should conclude that ________ air advection was occurring over Iowa. This type of advection was occurring broadly over the northern High Plains (see Minnesota and Kansas as other examples).

cold

Meanwhile, areas to the west and southwest of Lows can be expected to have ______ air advection.

cold

Not surprisingly, behind cold fronts one can expect ______ air advection.

cold

Temperatures further to the north and west of Iowa, Kansas, and Minnesota, based upon the isotherm plot, were found to be even ________ with temperatures mostly in the ________.

colder; 30s and 40s

Compare the Dallas advection pattern to that of Oklahoma City, just north of the developing Low. The wind flows and air mass advection patterns on opposite sides of the developing low-pressure center displayed ________ air flow advection patterns, consistent with the circulation expected around a low-pressure center.

opposing