FINALLY: SPRING OFFICIALLY ARRIVES

CAPE GIRARDEAU -- You shouldn't have to look at a calendar to know that spring is about to arrive. The weather has been spring-like most of the month, and even warmer weather is in store for the rest of the week.

The National Weather Service's mid-March to mid-April weather outlook calls for seasonable temperatures and above normal precipitation in Southeast Missouri and Southern Illinois.

Wednesday's high of 68 degrees at Cape Girardeau Municipal Airport was the warmest day of the year. There's a chance of showers and thunderstorms today, continuing through Saturday. Highs will be in the upper 60s today and reach into the mid-70s Friday and Saturday.

According to the Old Farmer's Almanac, the spring equinox occurs at 9:02 p.m. CST. That's the time the sun crosses the Earth's equator and enters the Northern Hemisphere. It also marks the first day of fall in the Southern Hemisphere.

On this day, which is also observed as Earth Day, the sun rises in the due east and sets due west everywhere on Earth (except near the North and South Poles), and the day lasts 12 hours and 8 minutes.

Al Robertson of the Southeast Missouri State University earth science department said the average temperature the first 19 days of March was 46.9 degrees, up 2.2 degrees from the long-term average of 44.7 degrees.

"The daily high and low temperatures tell the story," said Robertson. "Since the first of the month, we've had eight days when the daily high was 60 or above."

The warmer weather has caused many people to think about planting gardens. But don't get in too big of a hurry; although the overnight low hasn't dropped below freezing since March 10, Robertson said there is still plenty of time left for freezing weather.

He said the average date of the last killing freeze of winter the past 29 years is April 2. In 1990, the last killing freeze occurred on April 7. In contrast, the earliest date for the last killing freeze to occur was March 6, 1985. The latest date for a killing freeze was May 17, 1968, when a hard freeze forced gardeners to replant everything they had planted that spring.

While temperatures have been well above the long-term average this month, precipitation continues to fall behind, Robertson said. Only 1.15 inches of rain have fallen at the airport during the 19-day period.

"By this time of the month, we should have at least 2.2 inches," he said. "Of course, we could make that up before the end of the week." Normal precipitation for March is 4.41 inches. Robertson said March, April and May are traditionally the wettest months of the year in Cape Girardeau.

Until recently, the arrival of spring and warmer weather usually meant spring flooding on the Mississippi and Missouri rivers. But there hasn't been major flooding on either river for nearly four years, and the prospects for such flooding this year appear dim.

The weather service's latest outlook for snow-melt flooding on the Mississippi from its headwaters in Minnesota south to Chester, Ill. indicates the chances for major flooding this year are almost non-existent because of the small amount of snow over the upper Mississippi and Missouri river watersheds.

"There is a low snow-melt flood potential for the Mississippi River from its headwaters in Minnesota to Chester, Ill., and remaining tributaries above the mouth of the Missouri River," the outlook stated. The weather service said the flood outlook is based on conditions as of March 7, and assumes normal precipitation and melt rates from now until the normal period of snow disappearance. Complete snow melt for the northern areas of the upper Midwest are not expected until late March or early April, the outlook said.

But forecasters warn there still could be major flooding along the Missouri and Mississippi rivers this spring if heavy rainfall occurs during April and May.

Last year was a good example. The impact of the 1990 spring snow melt on the Mississippi between St. Louis and Cairo was minimal, but heavy rains that occurred during the spring months resulted in the first significant flooding Mississippi River flooding here since 1986.

Between 1988 and 1990 a major drought in the upper Midwest caused the Missouri and Mississippi rivers to drop to record low levels from St. Louis to New Orleans.

The Army Corps of Engineers said there was little improvement in the drought situation along the upper Missouri this past winter. Corps officials said the series of water storage reservoirs along the Missouri north of Kansas City will start the first day of spring with even lower water levels than at this time last year. That could mean more trouble ahead for the Mississippi River between St. Louis and Cairo later this summer and fall.

The last major flooding at Cape Girardeau occurred in October 1986, when the river crested at 42.1 feet, 10 feet above flood stage, on Oct. 12.

Other high-water marks at Cape Girardeau since then include: April 19, 1987, 31.2 feet; Dec. 30, 1987, 31.4 feet; and May 21, 1990, 39.6 feet.