A CAN OF CORN...

The sun was out and the wind whipping again Tuesday. Gusts were generally in the mid 30s, although a few spots clocked in around 40 mph. That's a little better than Monday, when gusts of 45 caused my cat Frankie to take a day off from his usual outdoor antics. For the most part, these W/NW winds have dominated much of April and that's gotten the month off to a cool start. After a very warm March, 11 of the 15 days this month have been below normal in Dubuque. That's a big change from March, when 23 of the 31 days were above normal.

I would categorize Wednesday's weather as falling under what I call a "can of corn forecast". I played for a baseball coach who would inevitably yell out when there was a pop-up or easy grounder, "THAT'S A CAN OF CORN SWAILS". It was a play (or out) you had to make, or it was into coaches dog house. Today's forecast of sunshine, lighter winds, and warmer temperatures looks like sweet corn after 2 days of gales and cool temperatures. It will start a little crisp though, with lows well into the 30s, perhaps as low as 28 in parts of the north. The 3K NAM shows this for temperatures around 7:00am.

Not to worry though as the April sun will do its thing and by late afternoon temperatures will be 30 degrees warmer in the low 60s northeast to upper 60s southwest with winds of 5-15 mph. Sign me up.

After that things get complicated fast as several disturbances eject out of this trough at 500mb. As always, the devil is in the details, so let's play ball.

The first thing to note about the storm track is that's fully aligned from the SW. That rapidly opens the door for moisture to surge into the Midwest. Wednesday morning, under the final vestiges of high pressure, cold dry air has water vapor levels as low as .28", bone dry.

36 hours later, water vapor has increased to 1.58" in southeast Iowa, with 1" levels all the way to Lake Superior.

Additionally, there is a 75kt jet streak at 850 punching into southern Iowa. That's likely to impinge on the moisture generating mainly elevated thunderstorms Thursday night. That could produce some strong storms with the primary threat being hail, lightning, and locally brief but heavy downpours in the more substantial updrafts. I would say the southern half of my area is most favored to see this round of convection. It's hard to say how widespread coverage will be.

SPC does have many of my counties in eastern Iowa and WC Illinois under a slight risk for this potential, mainly Thursday night.

Well after midnight, some pretty substantial instability (CAPE) shows up owing to the strength of the low level jet.

Before this even happens, warm air advection associated with the initial thrust of warm moist air may trigger scattered showers and storms Thursday morning, especially in the south. These should fizzle in the morning as Wednesday night's low level jet weakens early, allowing some capping to occur. That allows much of the area to get into the 70s setting the table for the instability for Thursday night's convection.

That activity is shown exiting early Friday, allowing a period of mixed sunshine ahead of a cold front. It appears enough heating occurs to get highs back up around 80 from the Quad Cities southeast. That again allows renewed instability and a chance for additional storms in the afternoon. However, it will be a race against time, and it appears the front clears most of my area before any storms would fire with the exception or the far SE which could still be in play. Models have been bouncing around some on this threat, and what happens Thursday night will likely play a role in how Friday afternoon unfolds. This will get clearer as we get closer to the event, however, I think the majority of any storms would be just east in central Illinois. I do think Friday will be a warm somewhat muggy day with highs in all but my northwest third into the 80s. Even there, mid to upper 70s look likely.

EASTER WEEKEND, MODEL DISCREPANCIES WITH BIG IMPLICATIONS

Saturday we are in-between storm systems and while cooler, a dry spring day is anticipated. Highs should range from around 60-65 making for pleasantly cool conditions.

Easter on the EURO looks pretty ugly, with a strong storm lifting into southern Iowa. It produces blustery conditions with showers and storms spreading into the far south by daybreak, reaching the north by early afternoon. Here's the surface features on the EURO

Temperatures show a pretty good contrast from north to south.

Rainfall on the EURO show some beneficial amounts in spots.

The GFS, in a major change, shows less phasing and takes the system further south with far less intensity. It keeps my entire area dry and maintains cool temperatures, although not as brisk across my northern counties, where some filtered sunshine is even possible. Here's its surface features Sunday

Highs on the GFS Easter

Precipitation is a no show.

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". No can of corn there. Roll weather...TS