Quiet weather for the bulk of today with well above average temperatures in the 30s northward to the 60s south. These spring-like conditions will quickly change tonight however as as a powerful cold front with a sinking high pressure center adjacent to it kicks into the area this evening, leading to cooling aloft, and eventually mixing downwards towards the surface. A very uncertain forecast lays ahead thereafter. Models continue to be unusually vexatious as of late. They have gotten things down to a rough 50-100 mile area, albeit moving around while doing so. There will likely be heavy snow somewhere across the snow today (upwards of Winter Storm Warning criteria), but confidence in where this will sit is unknown at this time.
The current expectation is that rain moves into the area in the afternoon hours today, hanging along the Highway 20 corridor. As the aforementioned cooler air rushes in from north to south, a brief period of sleet and freezing rain is possible near the freezing line as it gradually shifts south… roughly to the Interstate 80 area. Later on, a complete changeover to snow should be seen for the vast majority with heavy snow to be expected in many places. The total accumulations from this system won’t be paramount by any means, but it will pose a traffic impact on the Tuesday morning commute. The highest totals will be in the northeast-to-east central part of the state… around the Dubuque area. A Winter Storm Warning is already in effect on the other side of the border in Grant County, Wisconsin, where six inches is forecast. There may be some localized heavy amounts of 5+ inches… though this will probably not be widespread. The highest accumulations we will see will be along and around a line from Spencer to Fort Dodge to Waterloo to Cedar Rapids to Dubuque, where three-to-five inches is possible. One-to-three inches can be anticipated outside of this.
A Winter Weather Advisory has been posted for essentially the northeastern quarter of the state from 6:00 p.m. this evening to 9:00 a.m. Tuesday. It would not be of particular surprise to a portion of this in east central Iowa upgraded to a Winter Storm Warning… and the National Weather Service in the Quad Cities has already mentioned the possibility of this in their warning text. This is mainly for the travel impacts from the completely covered roads expected, however blowing snow is also a possibility with 10-20 MPH winds gusting to 30 MPH. This will all hamper travel Monday night and Tuesday morning, so please plan ahead for this.
In the long term, cooler temperatures can be anticipated with the fresh snow pack. Readings will be in the 30s and low 40s for the state on Tuesday with cloudy skies (including a brisk wind). Lows will hang in the 20s. A little bit of a warmer side through the end of the week with lower 30s to nearly 50 in the southwest. There are several chances of snow outside of tonight, including Wednesday night. Total accumulations with this will not be too concerning overall (or anything that would warrant an advisory).
Enjoy your Monday!