SHAKING WINTER...

5 days ago
3 min read

There's no doubt the worst of winter is well behind us. But, the cat and mouse game of two steps forward, one step back, is still very much an issue from time to time as we get these late season cold shots to ponder. The one that's over us right now is not for the faint of heart and the folks in the SW third of Iowa will attest to that Tuesday morning. Snow, (up to 6 inches of it) is projected making travel hazardous and creating a winter wonderland.

The disturbance that causes the snow will miss the majority of my area, aside from my far southwest counties where some slushy amounts up 1/2 inch are possible. The system has characteristics of a clipper with a strong band of warm advection streaking southeast along the southern fringe of the cold air currently in place. Locally, the cold air is so dry that I think saturation for precipitation will be difficult to achieve even in my southern counties. Here's what models are suggesting for snow totals into early Tuesday,

The HRRR

The National Model Blend

The GFS

The EURO

The 3k NAM, well overdone is suspect.

While we miss the snow, we will have some very crispy temperatures early Tuesday, particularly in the north where there will be less in the way of clouds. The HRRR shows this for lows.

From the look of things, return flow later Tuesday sends warm moist air over the top of the cooler air that resides at the surface. That should create an inversion that creates plenty of clouds and another chilly day in the 40s. While some drizzle or a few sprinkles are possible, rain chances increase more Tuesday night and Wednesday with strengthening war air advection. Temperatures will also moderate into the range of 65 to 70 but scattered showers and storms should be a factor from time to time. This is the first round of rain in a pattern that looks active and rip to be wet again in the long range over a broad sector of the central Midwest.

The driving force in the wet look is a western ridge eastern trough couplet that is shown April 19th. That places the baroclinic zone across the Midwest, (an area that is likely to see multiple periods of showers and storms). Precisely where the storm track sets up will determine where the most significant rains end up falling.

Taking a broad brush approach, this is what the GFS and EURO are showing for rain totals the next 15 days.

The GFS

The EURO

While this looks plenty wet, we are into the time of year now when rainfall steadily increases and in most spots the amounts shown are generally no more than 1/2 to 1.50 inches above normal.

As for temperatures, with the evolving trough out west this weekend. That should allow near to above normal readings much of the next 2 weeks. Not to say there won't be a bit more cat and mouse with cool air intrusions, I just don't see anything yet that looks anywhere near as fresh as what we just went through after Tuesday. The EURO looks like this.

The GFS is a bit more on the frisky side and has a rather healthy cool-down the middle of next week. That seems a bit aggressive to me at this point in time.