Wet. Windy. Gloomy. These describe the weather pattern that dominated spring 2011 in the Chautauqua Watershed. March through May, according to the National Weather Service Buffalo office, constituted the wettest spring on record.
Precipitation totaled 18.41 inches - twice the normal amount. Sunshine was 41 percent - 10 percent below normal. Temperatures were about normal overall, with summery temperatures alternating with cold. On April 22, enough wet snow fell on my yard that it started to accumulate, briefly.
Memorial Day weekend was beautiful with warm temperatures, but a week later in early June a friend in the town of North Harmony reported having to scrape frost off his car windshield. Farmers have had to wait for weeks for fields to dry to plant corn. Chautauqua Lake rose to record-high levels.
A late-May view downstream on the Chadakoin River. Mild, sunny days like this were infrequent in the Chautauqua Watershed this spring.
Now that we're in the second week of official summer we hope that wet cloudy spring pattern will give way to more summery sunny dry conditions.
Weather in the Chautauqua Watershed is affected both by air masses originating over the warm humid Gulf of Mexico and the cool dry interior of Canada. Depending on the movement of these air masses, our weather either will tend toward cool and dry or warm and moist. But why was this spring so rainy and gloomy?
Two reasons: La Nina and the jet streams.
Perhaps you've heard of El Nino, which is when Pacific Ocean water off the coast of South America is warmer than normal. La Nina is the opposite: cooler than normal Pacific Ocean water. From late summer 2010 through February 2011, La Nina was moderate to strong. It weakened slightly in March through April and now is in a "neutral" state with neither La Nina nor El Nino present.
Cooler-than-normal Pacific Ocean waters affect our weather through the jet streams. Jet streams are fast-moving "rivers" of air traveling generally west to east at the interface (known as the tropopause) between the troposphere (the bottom layer of the atmosphere where we live and where temperatures decrease with increasing altitude) and the stratosphere (the layer of the atmosphere where temperatures increase with increasing altitude). Passenger jets often "ride" jet streams to decrease fuel consumption and travel time on west-to-east flights.
This spring a single, very fast-moving jet stream remained farther south than normal over the Midwest, with wind speed more typical of winter than spring. A series of storms moving along the jet stream pulled up warm, moist Gulf of Mexico air, which mixed with cold Canadian air to produce some of the wet storminess that typified our spring. According to the National Weather Service Climate Prediction Center, "Accompanying (winter) La Nina conditions, large portions of central North America experience increased storminess, increased precipitation, and an increased frequency of significant cold-air outbreaks." Sound familiar? The strong La Nina of this spring not only produced exceptional winter-like strength to the jet stream, it apparently also set the stage for the massive tornado outbreaks in the south and Midwest.
Farmers are most directly affected by the persistent wet conditions we had this spring, and we hope that the coming weeks will continue to improve for growing corn and mowing hay.
The Chautauqua Watershed Conservancy's annual meeting will be at Webb's on July 24. Call CWC at 664-2166 for its summer preserve tour schedule. The mission of the Chautauqua Watershed Conservancy is to preserve and enhance the water quality, scenic beauty and ecological health of the lakes, streams and watersheds of the Chautauqua region. CWC's annual membership campaign is underway. For more information or to support these projects, call the CWC at 664-2166 or visit our website at www.chautauquawatershed.org.