OUR WILD WILD WORLD OF WEATHER...
A couple decades from now if you were looking at April temperatures in my area you would find most areas within a degree of normal. In other words, it was a pretty typical April.
However, averages are comprised of extremes and when you look at it from that perspective there wasn't much that was normal about the month. In Cedar Rapids April started cold but quickly warmed. Then we went into a prolonged stretch of chilly weather that lasted almost 3 weeks before a late surge of warmth closed out the month. Big swings characterized April with only a handful of days close to average. Ah yes, nothing like the wild, wild world of our weather.
That's been the case the past 3 months. Take a look at March and especially February which was really ugly from the 4th to the 19th.
Here's March, a temperature range of 9 to 71 degrees.
The deep freeze of February followed by a nice thaw. A range of 21 below to 42 above.
Big temperature contrasts have always been a part of Midwest weather, especially during the transition months of spring. Now it looks like May is loading up to do the same thing. Over this past weekend we started the month with highs in the mid to upper 80s Now, the other shoe drops and you can see why by looking at the projected 500mb jet stream pattern Friday. The door is again open to fresh Canadian air. Not a friendly look.
Thanks to this set-up Friday's temperature departures are 8-20 degrees below normal throughout the central U.S.
You can tell the source region of our air is Canada by its dryness. Water vapor is less than half what it typically is in May.
That leads to dew points in the upper 20s and low 30s by Saturday morning
With the dry air and the proper combination of light winds and clear skies some light frost is something to watch for late week. These are lows on the GFS Saturday morning.
With an abundance of dry air it's going to be tough to get much in the way of precipitation until we can attain a good return flow of moisture. The GFS swings a system into my southern counties Saturday night and deposits a healthy rain. Here's the surface depiction.
Rains of an inch or more up to I-80.
The EURO has a different depiction and one that I think has merit. It takes the disturbance on a more southerly track which most likely is the result of the dry air and high pressure in place to the north. My hunch is that the GFS will trend further south and in the end may look more like the EURO. Here's what the EURO's surface depiction looks like.
Its rain totals are significantly lighter in my southern counties. That makes sense to me at this point in the game.
Before this system arrives, there's a chance at some showers Wednesday night or early Thursday as a clipper like system delivers the cool dry air that should divert the worst of the weekend rain into Missouri and central Illinois. Best chances will b in north of I-80. Temperatures should average 5-10 degrees below normal the next few days with the EURO showing this for highs Wednesday through Saturday. Instead of going up, we're going down.
By the way, if you're wondering these are the rain totals from Monday. Some pretty nice amounts southeast of a line from Cedar Rapids to Dubuque. However, from there north totals were far less and rather disappointing.
That's all for now. Have a terrific hump day. I'm taking Eden to get her driver's license. She'll be in the road soon. Drive defensively and roll weather...TS