DRY: RAIN THIS YEAR SHORT OF NORMAL

March, April and May normally are the wettest months of the year in Cape Girardeau. It's a time when the soil gets much of the moisture it will need to sustain growing crops during the hot, dry summer months.

But this has not been a year for normal weather patterns, thanks to El Nino.

Rain at Cape Girardeau Municipal Airport during the three-month period amounted to only 8.24 inches. The long-term average is 13.62 inches; that's a deficit of 5.38 inches for the 90-day period.

To make matters worse, precipitation the first five months of the year at the airport is down more than one-third. Since Jan. 1, 13.59 inches of moisture have fallen at the airport. The long-term average for the period is 19.98 inches; that's a deficit of 6.39 inches.

Because of El Nino, the Midwest is dry and the Gulf Coast area from Del Rio to Florida is reeling from record-breaking rainfall and flash flooding. Texas has been especially hard hit. Parts of the Lone Star state have already had more rain than they normally get the entire year. Again, El Nino is to blame.

Climatologists say El Nino develops every few years in the eastern half of the Pacific Ocean. For some unexplained reason, an expanse of warm water several hundred feet deep and covering a large part of the eastern Pacific develops. This warming, together with the associated changes in the high-altitude jet stream winds and ocean currents, is the phenomenon known as El Nino.

Dr. Al Robertson, climatologist and professor of earth science at Southeast Missouri State University, said the latest El Nino weather cycle began in late 1990.

Robertson said the warming of the ocean currents in the eastern Pacific has caused major shifts to occur in the positions of the polar and sub-tropical jet streams, which normally interact and play an important role in weather throughout the year.

Since the El Nino cycle began, the polar jet has remained mostly along the U.S.-Canadian border, with only temporary fluctuations that have brought unseasonably cool temperatures to the area during the past three months.

On the other hand, Robertson said the sub-tropical jet, which normally intrudes northward into the Midwest in the spring, bringing with it unstable Gulf air, has remained along the Gulf Coast states.

"If you watch the daily weather maps, you can see all of the active, violent and wet weather is occurring from Texas to Florida and the southeastern United States," said Robertson. "That kind of weather is always associated with an active sub-tropical jet stream."

Despite the dry weather, there has been one positive side to the El Nino phenomenon in the Midwest this spring: the absence of severe thunderstorms and tornadoes. While the Gulf Coast states have been hit this year with severe thunderstorms, tornadoes, hail, heavy rains and flash flooding, Southeast Missouri and Southern Illinois have had little severe weather.

Normally, April and May are the peak months for severe thunderstorms and tornadoes in the Cape Girardeau area. This year severe weather activity has been at a minimum because of El Nino, Robertson said.

Robertson said he had expected El Nino to weaken by now, allowing the two jet streams to return to their normal positions. So far that hasn't happened, but Robertson, other climatologists and long-range forecasters now believe El Nino may begin to weaken sometime this year. But that may not mean any additional rain for the area.

While the 30-day weather outlook calls for near normal precipitation and temperatures, the 90-day outlook indicates above normal temperatures and slightly below normal precipitation.

Robertson said the warm-cold, roller-coaster weather pattern that's been going on since March continued in May. The average temperature for the month was 65.5 degrees, down 1.5 degrees from the long-term average of 67. The high for the month was 88 on May 16, while the low, 37, came on May 7.

For the first 10 days of May, the average temperature was 61.2 degrees, a drop of 2.6 degrees from the long-term average of 63.8.

Robertson said there was a considerable warmup during the middle of the month. The average temperature for the period was 71.7 degrees, up 4.6 degrees from the long-term 67.1.

Much cooler weather during the last 10 days of May dropped the average 6.7 degrees, to 63.7, compared to the long-term 70.4 degrees.

While precipitation here has been well below normal for the first five months of the year, monthly temperatures for the same period were averaging above normal, until May.

The January temperature average was 4.7 degrees above normal, while the February average was 7.7 degrees warmer than normal. The March temperature average was up 2.3 degrees from the long-term average, and April was up 0.6 of a degree. But May was down 1.5 degrees.

The long-term temperature average for June is 76 degrees. In 1991, it was 78.6 degrees, 2.6 degrees above normal. Rain was also well below normal last June, with only 1.05 inches, compared to the long-term of 3.88 inches.