Weather experts give their predictions for April through June
March 31, 2017
All eyes are on the hopeful forecasts for moisture to stave-off any drought conditions this spring in the central Rockies and central Plains states. Here are the latest prognostications for spring 2017; specifically April, May and June in Colorado, Wyoming, Nebraska and Kansas from climatologists, meteorologists and the official Climate Prediction Center's 90-day outlook.
Although much of eastern Colorado continues in a moderate drought, with a couple of pockets in the severe drought category of 'D2,' there's some hope — to make up deficits.
A Colorado State University climatologist noted that unfortunately, the eastern part of the state came out of the normally dry season (winter) and entered into the wetter season without seeing any uptick in moisture, with March staying dry in much of the state.
The latest 90-day outlook from the Climate Prediction Center shows equal chances for either above-normal, normal or below-normal precipitation in Colorado during April/May/June.
However, in this wetter spring season, there are indications of some good moisture producing storms.
"Ideally, we see the beginning of a more persistent pattern shift with more active storms that could pass over our state. If that happens and we have a couple more storms, we will quickly and easily make up the winter and fall moisture deficits and you would likely see improvement on the U.S. Drought Monitor map," said Becky Bolinger, climatologist/drought specialist at the Colorado Climate Center at Colorado State University's Department of Atmospheric Science in Fort Collins.
"Otherwise, without spring storms covering a widespread area or producing as much moisture as forecast, there would not be as much relief. In a case of continued warm, dry, windy conditions, then more locations in the eastern plains could enter D2 (severe) drought," Bolinger said.
Regarding the current impact on the growing season, many may have already noticed that vegetation is coming out of dormancy and plants are budding early. This is largely due to the unseasonably warm temperatures that the entire region has been experiencing over the past month. "Unfortunately, these plants are now vulnerable to any freeze events that could still occur.
Climatologically, the last freeze occurs in the region around mid-April, so it is still a possibility," Bolinger said. With upcoming storms, the Plains would fare much better if most of the precipitation stayed in the form of liquid, since frozen precipitation and frost could damage early buds. Bolinger said that vegetation will still be at risk for the next couple of weeks.
"Thankfully, the Climate Prediction Center is showing high likelihood of above-average temperatures in all of Colorado over this season, so it is possible we won't have any damaging freeze events."
Southeast Colorado has an even higher possibility of warmer-than-normal temperatures than the rest of the state this spring.
There's positive news on the horizon for drought-affected northeast Wyoming. The latest 90-day CPC outlook for precipitation shows slightly above-normal chances for precipitation in the northern three-quarters of the state, and even a bit higher possibility for extreme northeast Wyoming. This would be good news, as northeast Wyoming is still an area of concern.
"The northeast area of the state is low in terms of snowpack and is mostly in the moderate drought category of D1," said Tony Bergantino, deputy director, Water Resources Data System — Wyoming State Climate Office and Wyoming CoCoRaHS state coordinator. "The area was hit hard last year as well, when a drought got fairly bad in the northeastern counties, and in Big Horn County." CoCoRaHS (pronounced Co-Co rozz,) is an acronym for the Community Collaborative Rain, Hail and Snow network of volunteers of all ages and backgrounds working together to measure and map precipitation; rain, hail and snow.
The CPC outlook for the extreme southern quarter of Wyoming is showing equal chances of either above-normal, normal or below-normal precipitation for spring.
Much of Wyoming (other than the northeast part) is normal and even above-normal in terms of snowpack which is good news for areas that take their water from surface sources.
"Hopefully the snowpack comes off in an orderly and prolonged fashion. A wet season starting during the melt-out with rain on snowpack would accelerate the melt and cause more problems in terms of floods," Bergantino noted.
There is a slight chance of above-normal temperatures this spring for the southern half of Wyoming, while in the northern half — the computer models are showing equal chances of above-normal, normal or below-normal temperatures.
For Nebraska, there are encouraging signs for relieving drought-affected areas of the state, with predictions for above-normal moisture this spring. The CPC is also indicating above-normal spring temperatures in the cornhusker state.
"The CPC, in mid-March revealed a significant shift in their precipitation outlook for the central and northern Plains region. For Nebraska specifically, the models suggest above-normal moisture in the April to June period for areas north and east of a line from Fort Robinson (northwest corner) to North Platte to Auburn (southeast corner)," said Allen Dutcher, associate state climatologist for the Nebraska State Climate Office in Lincoln.
The northern half of Nebraska is indicated for above-normal moisture in the May to July period, with the northwest half of the state depicted in above-normal moisture from: June to August, July to September and the August to October periods.
"If this forecast verifies, along with the three-month drought outlook map, all drought signature in Nebraska would disappear before we reach the heart of the summer," Dutcher observed. "With the above normal moisture forecast in all three month periods from early summer through the fall, irrigation demands would come in below normal and grass/pasture growth would be above normal," he added.
Temperatures are forecast to be above normal in all forecast periods for the southern quarter of the state through the fall, with equal chances depicted for northern areas in May to June, and the June to August period.
However, Dutcher cautions that any extreme temperature swings would place the entire corn belt in an enhanced risk for hard freeze conditions into mid-April.
"Also, if the recent movement to an aggressive storm pattern continues (four major low-pressure systems moving into the central Plains into April,) the central and northern Rockies snowpack should continue to build through spring," Dutcher said, noting an early snowpack release for western Nebraska would reduce the chance of a drought spreading. "Unfortunately, it may also mean high flows on the Platte (River) into early summer, which would increase flood risks during spring storm activity," Dutcher said.
A potential increase in storm activity and subsequent moisture is not being directly attributed to the El Nino Southern Oscillation (ENSO) neutral conditions, but rather, Dutcher said, to a continuation of the pattern that dominated most of the winter.
"In addition to a greater conflict of cold/warm air masses, the atmosphere can hold more water vapor as temperatures slowly warm," he said. "Also, the jet stream lifts northward to its summer placement, putting the central U.S. in the favorable position of storm activity."
An active spring severe weather season is expected in Kansas, according to climatologists and meteorologists, due to an active jet stream pattern and storm track.
The official CPC outlook for April/May/June for Kansas indicates equal chances of either above-average, average or below-average springtime precipitation.
The climate pattern transitioned from a weak La Nina phase to an ENSO (El Nino/Southern Oscillation) neutral phase this spring, and is expected to remain neutral through summer.
"ENSO neutral conditions along with a strong pacific jet stream, suggest a typically active severe weather season could be in store for the Plains this spring. We've already seen the onset of severe weather across the Gulf Coast; more typical for February/March in that area, and gradually shifting north and west by April/May," said Chad Omitt, warning coordination meteorologist for the National Weather Service in Topeka, Kan.
In fact, the spring severe weather season actually began in late winter.
"The Storm Prediction Center reported 138 tornadoes for January 2017, with 11 in Texas while the three-year average is just 16. The Central Plains saw an unusual outbreak in December of 2016 with four in Kansas.
"If frontal passages align just wrong, there could be a higher-than-average number of severe storms. However, it only takes one event to have major impacts on an area," said Mary Knapp, assistant climatologist in Manhattan, Kan. "Forecasters are on both sides of the fence regarding spring severe weather," she added.
Interestingly, the Baron forecast team based in Huntsville, Ala., observed that this year's transition from La Nina to neutral conditions is the same climate pattern that brought severe storms in the spring of 2011 and 2012.
"While we don't expect this year's spring weather season to rival the historic severe weather season of 2011, it may fall more in line with the above-normal spring severe weather season of 2012," said Kevin Nugent, Baron's Enterprise customer project manager.
The CPC 90-day predictions indicate above-average temperature chances for northern Kansas, with greater chances for warmer temperatures in southern Kansas.
Unfortunately, the dry pattern in the southern Plains has intensified drought concerns. "Warmer than average temperatures from Kansas southward, increases concern about the winter wheat crop ending dormancy early. That'll make it vulnerable to winter kill, and cold temperatures are still possible into April," Knapp said.
Knapp noted there's a significant chance for El Niño conditions to develop this fall. "Warmer than normal Pacific Ocean temperatures (El Nino) tend to favor above-normal precipitation in the Central and Southern Plains."
High on the priority list to bust the droughts, would be the follow-through of the predicted active and warmer weather pattern bringing widespread precipitation with several storms over a longer period of time, Bolinger said. "We'd really like to see this pattern but with above-average temperatures — to minimize any chance that it would be snow — in order to protect the vegetation." ❖
— Hadachek, a freelance writer who lives on a farm with her husband in north central Kansas, is
also a meteorologist and storm chaser. She can be reached at: firstname.lastname@example.org