RISE, AND SHINE...

IN THE TRANSITION ZONE

Thursday, my region was smack-dab in the middle of what I would call a transition zone. Warm moist air was over-running a nearly stationary boundary stretched from SW Iowa into NE Missouri. On the cool side of this baroclinic wall of division, my area received plenty of clouds, cool temperatures, and in some cases scattered showers. The satellite shows the clouds at mid-afternoon quite prevalent over eastern Iowa and most of Illinois. That said, there was a little hole centered around the Quad Cities where some sun broke through.

Where that swath of sunshine was found, temperatures from the Quad Cities northwest reached into the low to mid 60s. On either side of that bubble of warmth, readings at 4:00pm were only 52 in Dubuque in the north, to 52 down south in the vicinity of Keokuk. A bit odd, but it goes to show you the power of the sun where it shines in late March. In this case, it was worth an additional 10–12 degrees.

Also, a narrow band of rain fell from about Independence to Clinton on to Princeton, Illinois. It produced totals of up to 1–2 tenths of an inch. Over the far south, down around Ft. Madison and Keokuk, another band produced amounts that were even heavier. Some 1/4 to 1/2 inch totals were measured. Probably 70 percent of my area saw little if any rain.

Some heartening news is that March precipitation is running above normal locally. Much of EC Iowa is 1.4 to 3.7 inches above average. For many, this will end up being the first month since November with above normal precipitation. Here's the March departures through Thursday the 27th.

These are the actual totals. Cedar Rapids is at 4.23 inches and in Muscatine the current total is 5.68 inches. Double check that for me, John Miller!

We are not done with the rain yet, as a new storm has eyes on the area this weekend, only to be followed by another potentially wet system next Tuesday night and Wednesday.

THE RISE AND SHINE SPECIAL...

In advance of that storm, Friday with be a day when temperatures rise, and the sun shines. That stationary front, situated to our to SW Thursday, is going to take off as a warm front Friday and by mid-afternoon has made it all the way into Wisconsin. Its warm advection sparked widely scattered showers and storms overnight. We should be able to walk out what remains early Friday. That allows sunshine to break out and temperatures to take off. While the HRRR may be a tad warm, with 850 temperatures of (+15/16 C) it shows readings poking into the upper 70s to near 80 around 4:00PM, close to existing records in the north. In SC Minnesota, it has a pocket of mid-80s! That sounds tasty to me.

With the very warm air aloft, a strong CAP builds that should keep any showers and storms from developing Friday, Friday night, and the bulk of Saturday despite respectable CAPE and instability.

How warm Saturday turns out is heavily dependent on a lake enhanced backdoor front that attempts to sink southward in the afternoon. Most guidance holds it off until late afternoon at the earliest near HWY 20. From HWY 30 south, the mild air prevails all day if current trends hold. Where the front passes up north, it will steer winds stiffly to the east and temperatures will quickly fall. That said, most spots Saturday should at least reach the low 70s for highs, aside from the far north, where readings may hold closer to the upper 60s before dipping later in the afternoon or evening.

The EURO shows this for temperatures at 5:00pm. Saturday. Note the contrast in readings from northern Iowa to southern Wisconsin compared to what's shown south of HWY 20.

The GFS is significantly cooler, but not nearly as cold as what it showed 24 hours ago.

Saturday night, the backdoor front approaches and stalls somewhere in my northern counties as a low pressure wave approaches. As forcing improves and moisture over-runs it, showers and a few thunderstorms are expected to develop late, especially in my NW counties. Eventually, these will advance into the rest of the region Sunday as the low and its cold front ease into Illinois. Outside the far north, most areas start off mild Sunday and then transition to colder air from west to east as the cold front passes. The EURO is slower with the wave and keeps mild air around much of the day. Check out the difference in temperatures Sunday at 5:00pm between the EURO and the GFS. So far, the EURO has been the most consistent in its depiction of a warmer solution.

The EURO

The GFS at the same time, 5:00PM Sunday.

Both models show a brief transition to snow in the north at the tail end of the storm. The GFS has it happening Sunday evening. The EURO late Sunday night or early Monday. Amounts have decreased the past 24 hours as the track has inched northward, meaning snow accumulations should be minimal at best locally, and confined to grassy and elevated surfaces closer to HWY 20. Here's a look at what models are suggesting for snow. Confidence in any solution remains low at this point.

The EURO

The GFS

As for precipitation, this is what is shown Thursday night through Monday in various waves of rain.

The EURO

The GFS

One thing is for sure, there is plenty of weather on the table, some good, some not so good. Friday should be the best of it, with very warm, springlike conditions. A definite keeper. Happy weekend and roll weather...TS