Ecology of South Florida (EVR 3013) LECTURE 3

CLIMATE OF SOUTHERN FLORIDA

HOLD BACK THE WATERS
The Seminoles left there with haste and with speed.
Their wise words of warning were given no heed.
When the waters receded, Great God what a site!
Men, women and children turned black as the night.

			Chorus:
				Lord hold back the water of Lake Okeechobee
				For Lake Okeechobee's blue waters are cold.
				When wild winds are blowin' across Okeechobee
				They're calling and seeking for other poor souls
				Oh Lake Okeechobee's blue waters are cold.

Now Lake Okeechobee is calm and serene.
The land all around it is fertile and green.
But the people get fearful when the wild winds do roam.
They look to the earth dam and think of their home.
Will McLean (1980) [in Jones and Sullivan 1995]

HANDOUTS:

Climate Data,
Climate Diagrams

I. INTRODUCTION

A. Weather

short term atmospheric conditions

B. Climate

average weather conditions of a region over a long period of time

C. Radiant energy

from the sun provides 99.97 percent of the total energy of the atmosphere

1. Intensity

depends on angle of sun, i.e. latitude and season

2. duration of sun

3. cloud cover

D. Heating

water heats and cools more slowly than land

E. Clouds insulate

F. Winds mix stratified air

G. Coriolis effect

H. Bermuda high

I. Sea breeze and land breeze

J. Gulf Stream

K. Potential Evapotranspiration

II. FLORIDA'S CLIMATE

A. Characteristics

(considered the single most important resources in the state)

1. Sunniest winter climate

in the eastern U.S.

2. Highest average Jan temperature in the nation

3. Average minimum temperature

exceeded only by Hawaii

4. Average annual maximum temperature

in southern Florida 5^oF less than most areas east of the Mississippi River and South of the Great Lakes

5. The Highest average annual temperature

in the country (tied with Hawaii)

6. Nine of the top eleven cities

in the country, as judged for having the most desirable climate

B. Classification

1. Southern tip of Florida

Savanna dry (Aw) Tropical climates have average temperatures of every month that exceed 64^oF

2. Savanna climates

have alternating wet and dry seasons

3. Rest of Florida

subtropical humid (Cf)

4. From Central Florida

west to central Texas and eastern Kansas and north to New York, summers are warm and humid but some months average below 64^oF.

5. Central and northern portions of the state

do not have the marked dry season that southern Florida has.

C. Temperature

1. Effect of land and water on temperature

No part of Florida is more than 75 miles from a major body of water

2. Average summer temperature

for the state is 81^oF and nowhere in the state does the average exceed 84^oF.

3. The highest recorded temperature

in the state is 109^oF in Monticello. Higher temperatures have been recorded in 40 other states.

4. Average annual temperature

72^oF

5. Effect of Latitude on Climate

Key West is located 24^o30' N (same as Sao Paulo, Tampico & Hong Kong). Northern most point in Florida is more than 100 miles farther south than the southernmost point in California

D. Precipitation

1. Water Budget

Approximately 150 billion gallons of water a day fall in the state in the form of precipitation. Another 25 billion gallons enter via surface and subsurface flow from Georgia and Alabama.

2. Water loss

Approximately 65 billion gallons flow out in rivers. The remaining 110 billion gallons flow exit via evapotranspiration. Ca. 13,500 gallons for every person in the state.

3. Summer rainfall

due to convective rains (diurnal heating of land surface), sea breezes, tropical storms and hurricanes.

4. Statewide annual

average is 54 inches, 1 inch less than Louisiana's average.

5. Summer rain

Miami receives much of its summer rainfall when the winds are from the southwest, keeping the onshore sea breeze near the coast - produces heavy rain and lightning

6. Range

Key West is the driest city in the state (40 inches). Miami Beach receives an average of 47 inches per year while Miami International Airport receives 57 inches)

7. Dry season

from November to May

8. North vs. South

South Florida dry season drier and wet season wetter than in northern Florida (EF)

9. World rank for Thunderstorms

Florida experiences more thunderstorms than any place except East Africa

10. U.S. Rank for lightning

More lightning occurs in Florida than in any other place in the US (EF). Tampa may be derived from an indigenous word meaning stick of fire and the city is often called the lightning capital of the world. Florida ranks first in lightning deaths per year (mean = 10).

E. Humidity

F. Winds

1. Sea breeze

may be felt as much as far as 30 miles inland

2. Trade winds

3. State rank

When the average number of tornadoes per 10,000 square miles is considered Florida ranks number 2, number 1 if water area is included.

4. County rank

Dade ranks second, behind Pinellas County, in the number of F2 tornadoes from 1880-1988.

F. Hurricanes

1. Number

In a typical year more than a hundred disturbances in the Atlantic, Caribbean and Gulf have the potential to form hurricanes. Fewer than 10 develop into tropical storms (winds > 34 knots) and only about 5 develop into hurricanes (winds greater than 64 knots)

2. Landfall

Coasts from Florida Bay to Melbourne and Pensacola to Panama City have the highest risk of hurricanes (expected rate of one every 6-8 years)

3. Our share

Forty of all hurricanes that have hit the U.S. have struck Florida.

4. Strength

Hurricane wind is strongest on the right front quadrant

5. Peak

for hurricanes is Sep and Oct

Selected hurricanes in Florida
Name	Date	Location	Deaths
unnamed	Sep 1926	Miami	243
San Felipe	Sep 1928	Lake Okeechobee	1836
Labor Day	Sep 1935	Matecumbe Key	408
unnamed	Sep 1945	Homestead	4
unnamed	Sep 1947	Hillsboro-Ft. Lauderdale	17
Gold Coast	Aug 1949	West Palm Beach	2
King	Oct 1950	Miami	3
Donna	Sep 1960	Southern Florida	11
Cleo	Sep 1964	East Coast	0
Dora	Sep 1964	Jacksonville	1
Betsy	Sep 1965	Keys and East Coast	8
Gladys	Oct 1968	Crystal River	3
Eloise	Sep 1975	Panama City/Ft. Walton	4
David	Sep 1979	East Coast	<5
Elena	Sep 1985	W of Cedar Key	3
Andrew	Aug 1992	Dade Co.	17

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