DUST IN THE WIND...
One of the traits May is noted for weatherwise is the uptick in precipitation we typically see in the Midwest. In the Quad Cities the monthly rainfall average is 4.82". Compare that to January when the average is 1.14". The reason for the dramatic increase is warmer air which in the physical sense can hold more water vapor. The more of that, the better your chances for higher rainfall totals.
The past 15 days little if any rain has fallen, especially to the SW of the Quad Cities. That's been the trend since February with 80% of the days at the NWS office in Davenport seeing no measurable precipitation. Since February 15th much of my area has built rainfall departures of 2-3 inches. That is not the way you want to start the growing season.
Things are not going to change anytime soon with a block limiting access to moisture and storms. Remarkably, conditions will only grow worse with some exceptionally dry air moving into the Midwest Wednesday night. I'm not sure if I ever remember seeing such low humidity levels as the EURO is showing the next 5 days in SE Iowa (especially in late May). Here's the humidity values the EURO is suggesting Wednesday through Monday in Ft. Madison, Iowa.
Wednesday-17%
Thursday-11%
Friday-12%
Saturday-13%
Sunday-15%
Monday-21%
Even if those numbers end up low by 5-7% that is still off the charts...essentially bone dry!
No matter what, that puts us in a rain free environment with water vapor around 0.15 inches come Thursday evening.
Below you can see the big high over the Great Lakes that delivers the dry air mass with its easterly winds.
Over the next 15 days the EURO is showing only scattered pockets of rain, mainly in the south. I would put little stock in what's shown as it all comes after day 12, a distance where its very unlikely the mesoscale environment is accurately portrayed. The big thing is the overall trend which is dry and not promising for widespread rain the next 2 weeks...particularly the next 10 days.
The 15 day deficits look like this on the EURO. Should this verify with current soil moisture conditions, it would put much of my area in abnormally dry to drought conditions heading into summer.
I also mentioned a back door cold front that is due in Wednesday afternoon. Ahead of it a warm dry day is anticipated with highs near 78 in the far NE to 90 in the far SW.
By Thursday morning, N/NE winds prevail and temperatures behind the cold front have slipped into the 40s north and low 50s south.
Those readings are as much as 20 degrees cooler than just 24 hours earlier.
However, the late May sun will not be denied and readings with abundant sunshine will rebound to near 70 in the north Thursday and the mid 70s south.
CATCH A HOT SUMMER DEAL AT ONE OF THE MOST UNIQUE ACCOMMODATIONS IN THE MIDWEST
THE HOLIDAY WEEKEND...
With the dry air mass in place this weekend temperatures will cool to comfortable levels at night and rise to progressively to warmer highs in the afternoon. The EURO has been consistently higher than the GFS and with the combination of dry air and strong sun I suspect it has the right idea. Here's the NWS IDSS point forecast for Davenport and it reflects the toastier idea of the EURO. Notice readings go from 73 Thursday to 87 Memorial Day. However, dew points are never higher than 52 and are mainly in the 30s and 40s. That 87 won't have the sizzle it could have with more moisture. In fact, the apparent temperature (how it feels) is actually 2 degrees cooler at 84.
With no threat for rainfall, this looks to be a rock solid holiday weekend of weather. Absolutely make those plans outdoors! Outside of a little dust in the wind, it should be near perfect. Roll weather...TS
