THE DEVIL IS IN THE DETAILS

Spring rains have been a bit sparse this year, with the major storm tracks splitting the Midwest. March got off to a decent start, but since then the rains have been very much hit-and-miss. Overall, the majority of Iowa and NW Illinois have precipitation deficits of 1 to 2 inches over the past 30 days. We need to pick it up before we get into the heat and more scattered nature of summer rain events.

To that point, there are a couple shots at beneficial rains starting Thursday and again Easter Sunday. In fact, some scattered showers and storms may already be at play early Thursday thanks to a low level jet over-running a slow moving warm front over the south. The jet will be at its peak early, so what activity can fire should be greatest in coverage and strength in the morning, then gradually diminish and end as the day wears on. The 3k NAM shows the rain with embedded thunderstorms around 9:00am lifting northeast.

What's made this possible is a dramatic increase in moisture. Wednesday around daybreak, when temperatures were in the upper 20s to low 30s, available water vapor was meager around .30 inches. Thursday afternoon those values should be at least an inch higher as shown on the 3k NAM. Winds also become a factor once again Thursday, gusting out of the S/SE over 30 mph. Temperatures are shown ranging from 62 north to about 70 south. Those numbers could vary a few degrees up or down, depending on the position of the warm front and the amount of cloud cover.

It appears that whatever rain materializes Thursday, there should be a lull late day and evening. However, moisture remains pooled over the region, with a nearly stationary boundary near I-80. After dark, the low level jet kicks in again and this time a more significant band of convection should develop near and north of it. I could see some training of cells in this type of environment, which could lead to a decent west to east rain band, especially with dew points in the upper 50s to low 60s. There is still some disagreement on where this swath sets up, but I would think the area north of I-80 is most favorable. If the warm front remains further south, the main show could be more over my central counties. Since most of the storms should be elevated, hail could be a concern in the stronger updraft cores. A few isolated strong storms are possible. As a result, SPC has much of my area along and west of the Mississippi in a slight risk outlook for scattered severe storms.

The EURO continues to show some health instability later Thursday night, with CAPE values up to 2,000 j/kg. Not at all bad for 5:00am in the morning.

Notice too, the 6-hour lightning flash rate around midnight. At least with this run, the EURO was all in for thunderstorms.

Friday morning, we walk out any lingering showers and storms very early in the day. After that, we await a cold front that should cross the Mississippi around midday. The speed of the front will determine if any additional storms can fire in my eastern counties in the afternoon. Most spots will stay dry. I'll keep a chance out for far SE Iowa and WC Illinois (southeast of the Quad Cities), but it looks to me like the best opportunity for anything significant will be higher just east of my area in central Illinois. Something to keep an eye on Friday, especially considering the amount of heating that is shown in the EURO. From the Mississippi east, highs on the EURO are into the low 80s. The NW is a little cooler due to an earlier frontal passage.

EASTER WEEKEND...

Saturday we are situated between storm systems and while cooler, a dry spring day is anticipated. Highs should range from around 58 north to 64 south, making for cool but pleasant conditions.

Yesterday, you may recall, the EURO and GFS had a falling out regarding a significant spring storm for Easter Sunday. The EURO had it and the GFS did not. Here's what I had to say about the situation then.

Frankly, this is a hard call as I have issues with both solutions. First, I am not sure that the rogue shift shown on the GFS is legit. I could see it come back north in future runs. Secondly, The EURO really shot the storm northeast into Iowa, and I am not certain that it will be that fast. I could certainly see a similar path, but it might be several hours slower, keeping some rain free hours in the south Sunday and perhaps much of the day dry until late afternoon in my northern counties. Either way, it does not appear to be a warm day, with highs 50s to perhaps low 60s in the far south. This is all speculation, so I will leave Easter as "still to be determined".

I was pleased to see that today my ideas had merit. The GFS is back on with the storm, and the EURO was not as fast or as far north with it. That could very well hold Sunday's rain off until 9:00am in the far south, closer to noon near I-80, and perhaps as late as 3 or 4pm in the far north...a rough guess. The bottom line though is that even before the rain arrives, it's going to be a blustery raw Easter with temperatures much of the day in the upper 40s to low 50s, hopefully no cooler (a possibility). Ironically, towards evening as the storm center enters SW Iowa, a warm front starts lifting northward that eventually pops temperatures into the upper 50s north to low 60s by midnight Sunday.

Here's the storm and its associated rain shield Sunday evening around 10pm.

By Monday morning, showers depart the north and clouds will decrease from south to north as the day wears on. Breezy, cool conditions are expected as winds switch back to the northwest.

Between Thursday and Monday morning, here's what models are suggesting for rain totals. This would do us all a world of good.

The EURO

The GFS

On your mark, get set, go! Roll weather...TS