SIGNS OF SUMMER BY MEMORIAL DAY...
After a frosty start in many areas, Wednesday turned into a pretty nice spring day with plenty of sunshine and light winds. And thanks to the combination of dry air and sunshine, highs overachieved a bit reaching 63-65 across the board. The quiet pattern is the result of of a sprawling high pressure that's been slow to drift east. You can see the center of the big boy situated over Milwaukee Wednesday evening.
Clearly evident on the satellite is the dry air under the high that's confined moisture, clouds, and precipitation to the deep south. That's a pretty good push for mid-May.
It's resulted in temperature departures over the past 5 days that look like this. Ouch, way below average! It's interesting to note that after starting May with two days of highs in the range of 85-90, the month is now running about 2 degrees below normal. It's been all downhill since May 4th.
Under the high Wednesday morning, lows were again cold enough for frost with readings in the low to mid 30s. The mercury hit 32 in Independence, Monticello, and Freeport. Even Moline dipped to 33 as did Dubuque and Waterloo.
We'll remain close enough to the high to have another sensational day Thursday with full sunshine, light winds, and highs close to 65. A keeper.
Heading into the weekend moisture is expected to make an effort to return to the Midwest as the high retreats to the east and return flow kicks in. However, models have shown a trend to keep the deeper moisture and heavier rains further south closer to the Missouri border. Considering the depth of the dry air that concept does has merit.
No matter what, 3 disturbances will ripple through the area bringing at least shower chances Friday night, again Saturday night, and perhaps for a third time later Sunday or Sunday night. By no means will the weekend be a washout with many dry hours. But there is likely to be periods of clouds and temperatures will be limited by the extent of the overcast. For the most part highs will be confined to the 60s, although the GFS has a lot of 50s around Saturday. The EURO is about 10 degrees warmer. I would lean more toward the EURO, especially if clouds can thin or even break for an hour. Between the 3 precipitation windows, here's what the GFS and EURO show for total rain between Friday night and Sunday night. I wonder if this might be a bit robust, especially north of I-80.
I am now in summer mode and I'm in search of the first sign of extended warmth and the MJO seems to be signaling that possibility by Memorial Day (and the last week of May). If you follow the green dots below you can see the MJO coming out of the cool phases of 2 and 3 heading directly for phases 4, 5, and 6. The phase analogs for phases 4, 5, and 6 all show warmer than average temperatures in May (see the phase analogs to the right). Phase 6 is especially warm and that's where we should be headed around Memorial Day according to the GFS. Take a look.
The day 11-16 temperature departures on the GFS ensembles reflect the idea with readings that look like this May 23rd-28th.
I'm totally fine with the warmer look as by that time fall is only 3 months away. I want me some summer! I guess I'll leave it at that. Enjoy what is likely to be a beautiful Thursday. Roll weather...TS