A Colorado meteorologist has some bad news regarding upcoming weather conditions in Colorado and Wyoming. “I wish I had better news, but the forecast is for continued dry this winter into spring with drought continuing for eastern Colorado and Wyoming.”   

The latest weather prediction for November, December and January issued by the Climate Prediction Center Thursday, Oct. 17, is leaning toward drier than normal conditions.

A storm system moved out of the Desert Southwest and across Colorado Oct. 20-21, which provided some precipitation in southern Colorado. “But once this system moves out, I don’t see much on the horizon until possibly mid- to late-November based on the Madden Julian Oscillation,” said Kyle Mozley, meteorologist, National Weather Service, Pueblo, Colo. (The MJO is described as an eastern flow of clouds, rainfall, winds and pressure.)  

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Drought continues to worsen, especially across eastern Wyoming, and looks to persist through November. 

This winter’s La Nina may impact precipitation across Wyoming this winter. The wet conditions forecast across the Pacific Northwest may shift a bit eastward across the Northern Rockies and nudge into Wyoming, Mozley said, which is the reasoning for the equal chances of above, near or below normal precipitation.  

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However, the further south you go across Colorado, the outlook becomes drier and drier, Mozley said. “Looking at the La Nina historical dry/wet risk plots, the outlooks through February/March/April follow these plots well… dry with a brief near normal/wet period across eastern Wyoming for December/January/February, and drying back out into the spring. Further south across Colorado, dry conditions are favored,” Mozley noted. Drought is predicted to prevail across eastern Wyoming and Colorado and into the Central Plains.  

MOISTURE CHANGES

“The modeling I use has an active MJO event in mid- to late-November (18-26 time period), which may bring another brief period of active weather, but outside of that, it looks dry,” Mozley said. As for the Colorado mountains, La Nina tends to favor wet conditions across Colorado’s mountains in the December/January/February time frame, but will also need to have help from other climate “tele-connections” such as the North Atlantic Oscillation, Arctic Oscillation and Pacific North America. And, this only pertains to the Colorado mountains, Mozley said. 

So, there is a 75 percent chance of La Nina developing by the end of the year, although the event is expected to be rather weak and short-lived. Therefore, impacts on the North American winter weather may be more muted than previously expected. La Nina (the opposite climate phenomenon from El Nino) influences global weather by its cooler than average ocean temperatures in the equatorial Pacific. The news is best for the northern tier of states, with more moisture and colder temperatures. “Although there is no indication of sustained cold winter weather for the central Great Plains, La Nina winters occasionally feature episodic temperature surprises, such as the epic February cold waves of 1989 and 2021,” said Brad Rippey, USDA meteorologist, Office of the Chief Economist, World Agricultural Outlook Board in Washington, D.C. Rippey noted, that following a drier-than-normal first half of autumn which has left topsoil moisture depleted in many areas of the country, ongoing dryness across portions of the central Great Plains could lead to further deterioration of rangeland and pasture conditions, as well as poor establishment of newly planted winter grains and cover crops.

DROUGHT PERSISTS

As of the week of Oct. 15, Wyoming is now completely in drought for the first time since Sept. 21, 2004. Many stations around the state are experiencing runs of 25-30 consecutive days with zero precipitation.

There is hope, especially for extreme northwest Wyoming’s precipitation this winter, with above normal chances of precipitation indicated in the Climate Prediction Center forecast for November, December and January.

“For the rest of Wyoming’s winter precipitation forecast, however, it is mostly an even game for above or below average,” said Tony Bergantino, director-Wyoming State Climate Office-Water Resources Data System, University of Wyoming, Department of Atmospheric Science/Wyoming CoCoRaHS State Coordinator–Wyoming Mesonet director. 

As we go further out into winter (December to February) the chances for below normal temperatures increase a bit but only across the very northern tier of Wyoming. Better than average chances for above normal precipitation expand a bit more in the northwest, which covers roughly the northwest corner of Wyoming.

La Nina is expected to emerge before the end of the year (a 60% chance in the September to November quarter), and if it does, it is expected to last through the January to March period. 

“La Nina for Wyoming generally means cooler than normal temperatures and above normal precipitation, especially for the northern parts of the state. Unfortunately, as Wyoming is at the boundary of La Nina influence, a lot will depend upon the positioning of the Polar and Pacific Jet Streams so the extent of the temperature and precipitation is variable,” Bergantino said. 

Lastly, for Wyoming there are always ag concerns in a state that receives the amounts of precipitation that Wyoming does and any negative deviation from that can put strains on water supplies. Soils are extremely dry around much of the state as we go into winter, Bergantino noted. 

NEBRASKA

La Nina during late fall and winter in general tends to lean drier. However, a Nebraska climatologist said the state could get enough snowfall this winter to help things out.

“The only thing that lets us get major drought improvements this winter would be for persistent deep troughs in the western U.S. to help spin up storms off the Front Range with high pressure off the southeast coast to pump Gulf moisture up. Then, we’d be talking about a very active, stormy pattern,” said Eric Hunt, Ph.D., assistant Extension educator of Agricultural Meteorology and Climate Resilience, University of Nebraska-Lincoln and the Nebraska State Climate Office. “Given the way we seem to swing more often from one extreme to the other with the climate warming, I won’t totally discount that,” Hunt added.

Without appreciable rainfall for two months, combined with dormant/dead vegetation, as well as low relative humidity and gusty winds, not to mention parts of Nebraska are increasingly seeing severe drought conditions, extreme caution is advised to prevent fire danger. Folks with UNL’s Cropwatch note that soil moisture percentiles are below the fifth percentile statewide and across much of the central U.S., so the landscape is especially dry and, unfortunately, primed for rapid spread of fire.

KANSAS

Regarding Kansas’ agricultural impact heading into late fall and the winter, the Central Plains still finds itself on the November through January forecast gradient of favorable cooler/wetter conditions to the north (Northern Plains) and warmer/drier favored in far southwest Kansas and southward. Also, wheat has been dusted in for much of the state.

“Some emergence has occurred for earlier planted wheat, and with the lack of surface moisture, emergence will likely remain a struggle into the winter and blowing dust and erosion will be big concerns. The state recently observed a widespread freeze that will reduce the heavy pest issues on young wheat,” said Christopher Redmond, assistant meteorologist, Kansas State University Weather Data Library/Mesonet manager. With ponds extremely low or non-existent and stream flows limited at best, water hauling will be necessary, Redmond said. Public water supply will also be a continuing concern, especially for the Cheney Reservoir and the city of Wichita and other communities that are already under water conservation orders. However, there is hope. “With a weak La Nina and negative Pacific Decadal Oscillation still expected, this suggests prominent northwest flow across the Plains and this pattern typically favors drier conditions with warmer temperatures. However, subtle shifts in the pattern southward remain possible and could briefly provide some needed (and hopefully timely relief),” Redmond said.