Good afternoon everyone! Most of IA and NE are dry as of 4:05pm CST. However, there are some very light snow showers clipping the far northeast portions of IA while our incoming storm system is beginning to enter the northwestern portions of the NE Panhandle. The overall drier weather we experienced over the last couple of days after the early weekend storm system (excluding IA’s clipper yesterday) will cease as this next system brings a round of accumulating snow to virtually all of NE and IA with even some minor ice accumulations as well.
As the system works into the Central Plains tonight through the day Tuesday, we’ll note expanding snow and light freezing drizzle/rain coverage across NE and IA. Frontogenesis (aids in lift and the development of snow) will increase as the low pressure system works across northern KS through northern MO/southeastern IA late Tuesday into Tuesday night. Where this enhanced frontogenesis sets up (likely from far east-central NE into the northern half of IA), a heavier band of backside snow will be likely develop and lead to an area of 5-8″ of snow; More on amounts discussed later! Further west likely observes less snow as the lift won’t be as sufficient in the DGZ while freezing rain mixing in further south will limit snow totals.
Here’s a look at the current winter weather bulletins across IA and NE: The vast majority of these states are under Winter Weather Advisories due to snow accumulations or a mixture of snow and ice accretion. Winter Storm Warnings have recently been hoisted in far northeastern IA given the significant snow accumulations expected there from the National Weather Service as well as portions of the NE Panhandle. A Blizzard Warning has been issued for the very far southwestern county in NE.
Simulated radar through 9am CST Wednesday: Note the next wave of snow develops in the NE Panhandle through the remainder of the afternoon into the evening hours while lighter snow coverage will begin in far northern NE/IA overnight. Just to the south of this area, there likely won’t be enough saturation in the DGZ initially so areas of freezing drizzle/rain will be likely, especially in eastern NE and western IA. Progressing through the morning hours Tuesday, expect the areas of freezing drizzle/rain to gradually transition to snow in southern/eastern NE and the remainder of the northern half of IA. We’ll also note Tuesday morning the snows gradually starting to pull out of northwestern NE and eventually the western half of the state by Tuesday evening as the storm system lifts east. Also by Tuesday evening, a band of backside snows along the northwestern periphery of the storm system will have developed, impacting eastern NE into IA (excluding southeastern IA where warmer air will keep the precipitation type as rain). The low pressure system will continue its journey northeastward Tuesday night with the backside snows working west to east across IA. It won’t be until 7-8am CST when the snows finally exit northeastern IA and the region becomes dry again.
As previously discussed, we are watching the initial threat for light freezing drizzle/rain across the eastern portions of NE into a good majority of IA. Once the light freezing rain transitions to snow the ice accretion threat will no longer be a problem. However, by the time this happens we will be looking at a light glaze of ice around 0.05-0.1″ for many in the aforementioned areas.
Here’s a look at total snow accumulation by Wednesday morning: Continuing to target the northern portions of IA and far east-central NE for the best chances to observe 5-8″ of snow. Lighter amounts will be more prevalent in southern IA and further west into the remainder of NE. Even with the latest runs of new model guidance, there are discrepancies in central NE (especially for Grand Island and locations north). We are still favoring the European’s approach to a more easterly solution, but can’t rule out higher amounts in these aforementioned areas given some guidance being more pronounced with backside banding (there’s frontogenesis but limited saturation in the DGZ). We remain in the lower snow amount range in central NE, but note that actual amounts could be higher given any pronounced banding that may occur. One thing is for certain in relation to all guidance and that is there will be a decent snow hole (less than 1″ total) setting up north and west of O’Neil, NE.
As the storm system strengthens over the southern portions of NE and IA, winds will pick up. This will be especially true during the day Tuesday as winds will likely gust to 35mph at times in NE and to 30mph in IA Tuesday night. Expect lower visibilities at times during times of snow as well as blowing/drifting snow. Near-blizzard to blizzard conditions are expected in southwestern NE Tuesday as a result of the stronger winds. Something to note if you are traveling during this period as you should anticipate most roads to be snow covered and slick.
Simulation of temperatures from this evening through Wednesday morning: Note the warm nose of air trying to lift northward into southeastern NE and southwestern IA. These will be the areas at the highest risk for ice accretion tonight into Tuesday. However, the storm system as it passes will usher in colder air from the north and progressively drop temperatures from west to east across NE tonight into Tuesday morning, then IA Tuesday afternoon into Tuesday night. By Wednesday morning, low temperatures falling into the single digits in places will be common in IA with teens more likely into NE. Wind chills will fall even further as some areas will remain on the breezy side.
If you have any questions do not hesitate to reach out! Have a great evening!