May be headed for a wetter-than-normal spring in some areas
for The Fence Post
After a typical wet and cold El Nino winter and preparing to morph into spring, farmers and ranchers have their eyes on the newly released critical spring weather prediction. Released Feb. 21, 2019, the Climate Prediction Center said March, April and May temperatures and precipitation are linked to an El Nino Advisory.
“The (previous) El Nino watch is now an advisory, as weak El Nino conditions have a 55 percent chance (instead of the previous 80 percent chance) of continuing through this spring,” said Matthew Rosencrans, Climate Prediction Center’s head of forecast operations in College Park, Md.
During the winter, El Nino, associated with the jet stream shifting further south into southern California and moving eastward through the central Plains, increased winter precipitation in its path.
“The jet-stream will now shift northward through March, as the seasons progress. While there’s a 55 percent chance that El Nino stays on through March, April, May, however, by June. July, August, the most likely status will be neutral,” Rosencrans said.
A meteorologist with the U.S. Department of Agriculture says odds are tilted toward a wetter-than-normal spring in many areas, especially from the central and southern Rockies into the Southeast, although slightly more likely in Kansas and Colorado versus Nebraska and Wyoming.
“During the next few weeks, winter-like conditions can be expected to persist across the Plains and upper Midwest, per CPC’s March temperature outlook,” said Brad Rippey, USDA meteorologist in the office of the chief economist at the World Agricultural Outlook Board in Washington, D.C.
At some point, Rippey said, there may be a quick transition to summer-like temperatures, similar to what we experienced in 2018. “Last year, the U.S. had a cold April and a warm May, resulting in the greatest U.S. temperature differential on record between those two months.
Snowpack is currently favorable, Rippey said, (mostly normal to above normal) in the central Rockies (https://wrcc.dri.edu/snotelanom/basinswe.html) ensuring that there should be a good water supply for producers who depend on the snow-melt season. “The spring forecast indicates that favorable precipitation should continue in mountainous areas of Colorado and neighboring states.”
“Given the overall stormy pattern across the U.S. this winter, most rangeland and pastures should be in pretty good shape for spring green-up,” Rippey said, noting that there’s no U.S. drought east of the Mississippi River, and only patches of drought east of the Rockies. However, one drought patch covers important cattle country on the southern High Plains (west Texas). According to the latest report from USDA’s National Agricultural Statistics Service (https://www.nass.usda.gov/Statistics_by_State/Texas/Publications/Crop_Progress_&_Condition/tx-cw-02-17-2019.pdf), 28 percent of the winter wheat and rangeland/pastures in Texas were rated in very poor to poor condition on Feb. 17. Topsoil moisture is at least 80 percent short on the Texas high plains.
Specifically for Colorado, the official spring outlook indicates a slightly enhanced possibility of wetter than average conditions for March, April and May 2019.
“There aren’t really any signs pointing to a wet pattern for our spring, but there may be just enough of a signal to shift the probability slightly,” said Becky Bolinger, assistant state climatologist for the Colorado Climate Center at the Colorado State University Department of Atmospheric Science in Fort Collins.
Regarding Colorado’s spring temperatures, the CPC outlook calls for equal chances of near, above, or below normal temperatures for Colorado. “What this really means is the Climate Prediction Center has no confidence in the seasonal model outlooks, or that the models have no consensus, so we don’t really know.”
Colorado could have a cold March. “Given our current pattern, combined with the official arrival of El Niño, I’d say we’re at a pretty low risk for a hot and dry March. I think we’ll be holding onto the winter temperatures for a little bit longer, which is great news for mountain snowpack,” Bolinger said.
In typical El Niño spring seasons, there has been a lower probability of dry extremes, which is also good news for the state. “I’d say there’s a lower chance for drought development this spring, and I’m keeping my fingers crossed for a big whopper of a spring blizzard on the Front Range,” Bolinger said.
While December through February is typically the driest time of year for the eastern Plains, it’s been a bit drier than normal. “Thankfully, deficits however, can easily be made up in spring. And with cold temperatures, there probably haven’t been too many concerns about vegetation coming out of dormancy early, which would then be more vulnerable to spring freeze events,” Bolinger said.
Finally for the Colorado Plains, March through April brings the typical transition to many windy days. “If there are hot and windy days with low RH (relative humidity,) we can expect lots of red flag days (risk for fires). Fall wetness and spring dryness are good ingredients for fuel for fires. Colder temperatures could help minimize that risk. But we are entering the prime season for fires, so it’s good to stay aware,” Bolinger said.
Wyoming’s cold temperatures and above normal precipitation going into March should help maintain and hopefully build a snowpack that’s average to above average for this time of the year.
Then, into March, the precipitation forecast signal fades and Wyoming moves to a neutral condition where there are equal chances for either above, below or just normal precipitation.
For the full spring period (March through May), the overall signal indicates better chances for above normal precipitation in the southern three-quarters of Wyoming. “But that signal is still rather faint, although it gets stronger toward the southern tier of Wyoming,” said Tony Bergantino, deputy director of Water Resources Data System for the Wyoming State Climate Office and Wyoming CoCoRaHS state coordinator.
Regarding temperatures in Wyoming in March, there are nearly even chances in the western two thirds for above, below or normal temperatures. “There is a slightly better signal in the eastern third of Wyoming for below-normal temperatures. For the full spring period (March through May,) the signal fades out in the east,” Bergantino said. Above normal temperatures are more likely in Wyoming’s western quarter.
“I am hopeful that the next two to three weeks will continue keeping our snowpack at or above normal. There is a better than 50/50 chance that these (El Nino) conditions will continue through the spring; which could still cause localized effects,” Bergantino said.
“March will likely delay the feel of spring with temperatures expected to average below normal, although odds favor closer to normal or possibly above normal temperatures into April and May,” said Michael Moritz, warning coordination meteorologist at the National Weather Service in Hastings, Neb.
Regarding precipitation, “Though likely highly variable from one location to another, precipitation is expected near normal in March, but does favor slightly above normal precipitation into April and May, more so across Kansas and Nebraska than the northern Plains,” said Moritz, noting the atmosphere has responded to weak El Nino conditions in the central Pacific Ocean. “So, it’s not uncommon to have periods of wet weather as the winter rounds its way into spring.”
Frost depths are about average, but snow cover is a bit more widespread than normal. “It’s likely it will take time for wet conditions to dry, and the colder late winter temperatures to warm, both of which could delay spring field work,” Moritz said. “Crop producers may have to be patient in terms of starting spring field work, but should be ready to hit the ground running, once weather conditions allow. Ranchers should be prepared for the colder than normal temperatures and potentially wet conditions throughout the spring calving season,” Moritz said. “However, grass conditions should be favorable for much of the central Plains once it warms up, given the run of wet weather the past several months.”
A Nebraska climatologist agreed, the start of a wet spring appears in store for the Cornhusker State.
“With El Nino like conditions expected through this spring, we should continue to see the southern jet contribute to above normal precipitation south of the I-80 corridor (western Corn Belt: Nebraska, Kansas, Oklahoma, Texas) as well as Missouri, Iowa, southern Minnesota into the mid-Atlantic region,” said Allen Dutcher, associate state climatologist at the Nebraska State Climate Office in Lincoln. Dutcher expects this trend to continue through much of March as the northern jet has become a bigger player during the second half of the winter. “In fact, some of the strength came at the same time as a small pocket of upwelling cold anomalies made it to the surface in the extreme eastern Equatorial Pacific. This area is beginning to show signs of fatigue and the warm sub-surface heat just to the west of it is coming to the surface. This should reinvigorate the southern jet like we saw during early winter, and I would not be surprised to see a weakened northern jet develop, creating a split flow pattern. If this occurs, then drier than normal conditions are likely over the next three months across the northern Rockies, western Dakotas and northern Minnesota. Heavy moisture would be favored for the southern Plains and southern Rocky Mountains,” Dutcher said.
Bottom line, Dutcher said the challenge continues for cattle folks, from frequent activity. “With a more southern stream component, storms will hold more moisture and precipitation events will be much wetter, which is a nasty ingredient to have when calving,” Dutcher said. If the northern stream remains active, planting delays could result. “But If the southern stream strengthens, I see enough breaks between events that planting could still be done in a timely fashion.”
After an El Nino winter that’s had a tight hold over Kansas, March continues calling for an increased chance of cooler than normal temperatures across Kansas. The signal is strongest in the northeast, and weakest in the southwest.
The precipitation pattern for March is less clear, with equal chances of above normal, normal or below normal amounts.
“A normal or slightly below normal precipitation pattern for March would be favorable in the eastern divisions, where saturated soils continue to linger from the excessive fall moisture. Cool temperatures would slow the normal drying pattern,” said Mary Knapp, assistant state climatologist, located at Kansas State University in Manhattan. “If that is coupled with wetter than normal conditions, planting delays could be problem. In addition, flooding could also be an issue, as streams, ponds and reservoirs are full.”
Regarding the full spring season, the temperature outlook switches to the neutral pattern, with equal chances for above normal, normal or below normal temperatures. “A big concern would be a repeat of the 2018 pattern, where much colder than normal temperatures prevailed in April, to be quickly replaced by much warmer than normal temperatures in May. This narrowed the reproductive period for winter wheat, with a negative impact on yield,” Knapp said.
Also through springtime, there’s a slight chance for above normal precipitation state-wide, Knapp said. A slightly drier than normal March or April, that allows for an adequate planting window would benefit eastern divisions. “Meanwhile, the western third of Kansas has drier soil moisture at the surface, and would benefit more from a normal precipitation pattern,” she said.
El Niño’s weakest correlation is in the spring season. “Impacts are more likely to be the result of an active Madden Julian Oscillation, which results in increased frequency of storm systems,” said Knapp, which would increase chances of normal to above normal precipitation in Kansas. “Additionally, there is a negative pattern in the Arctic Oscillation which is forecast to continue through the next few weeks,” she said. “This makes cold intrusions into the Plains more likely.”
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— Hadachek is a freelance writer who lives on a farm with her husband in north central Kansas and is also a meteorologist and storm chaser. She can be reached at firstname.lastname@example.org.