Expected Moderating Temps, Rain Welcome Relief for Central U.S. Farmers
Parts of the nation's center that have seen the most severe dryness and heat in the last two years look to see a break from those painful conditions in the coming weeks, according to new forecasts.
The most substantial improvements will come in the western and southern Plains, the epicenter of the drought in the central third of the U.S. in the last 24 months, says MDA Weather Services senior ag meteorologist Don Keeney.
"Abundant rains in the west-central and southern Plains will continue to replenish moisture there, while rains in the central and southern Midwest and Delta will maintain abundant moisture there for corn and soybeans," Keeney said Wednesday.
In the last few weeks, rain has been more common in the parched Plains, but it's yet to fall in ample amounts in the most drought-stressed areas. That's likely to change, says Nebraska state climatologist Al Dutcher.
"During the past few weeks there has been a significant increase in precipitation events across the central U.S.," he says. "The most widespread event occurred across Texas the third week of May as an upper air low slowly drifted from the southwestern desert region into lower Mississippi river valley. Pockets of heavy precipitation have occurred across Nebraska and Kansas, but generally have fallen outside areas reporting the most intense drought conditions."
What's been behind the shift? A trend toward El Niño in the Southern Oscillation Index -- one that typically signals more ample rainfall in the central contiguous U.S. -- has begun, but there are also anomalous factors in play right now, Dutcher says. It could foreshadow more needed rainfall for the Plains moving into summer.
"The reason for such an optimistic forecast is centered on the trend of upper air trough formation over the central and northern Rockies during June that will pull low-level Gulf of Mexico moisture northward in advance of the surface lows that will form on the eastern slopes of the central Rockies. Mid-level moisture from mountain snowmelt will add additional moisture into the atmosphere over the central Plains, which will help increase precipitation output of surface lows that cross the state," Dutcher says. "In addition to these factors for above-normal moisture, a Pacific hurricane formed off the western coast of Mexico and moved northwest of the southern Baja Peninsula last week. Usually we don't see this type of hurricane track until the second half of the summer. These systems are very efficient at bringing moisture into the southwestern U.S. and enhance the monsoon moisture feed into the central Rockies.
"We will need further confirmation that this hurricane wasn't an outlier. If additional tropical systems over the next month take a similar path, this would confirm the Climate Prediction Center forecast of an active monsoon season. An active monsoon season, coupled with a strong moisture feed into the central Rockies would be supportive of increased moisture tendencies for the western High Plains region, including Nebraska," Dutcher adds.
Though the rainfall is welcome relief for countless U.S. farmers, it won't mean a complete exit from drought conditions. And the shift could also mean higher chances for severe weather, including tornadoes.
"While we don't expect the current drought to entirely disappear from the central Plains, it would not be unexpected to see a 1- to 2-category improvement for most locations north of central Kansas before the end of June," Dutcher says. "Unfortunately, we will have to endure several rounds of severe weather including widespread wind and hail events. Current weather models are projecting a few tornadoes, but not a super outbreak."
Farther north and east, the rainfall will be more spotty and difficult to predict, Keeney adds. Yet the moisture that parts of Corn Belt have received will likely be enough to prevent any summer moisture shortfall from inflicting crop damage, with just a few exceptions.
"The precipitation outlook is slightly wetter in the central Midwest, and slightly drier in the western Midwest. Some slight dryness may develop in the northwestern Midwest, although no major crop stress is expected," he says. "The drier pattern in the northwestern Plains and far southern Prairies will likely stress spring wheat a bit.