ENOUGH OF THAT HOT SAUCE...
Holy cow, is this weather wild or what? I like a little hot sauce on my taco but not the angry hellfire brand that burns your tonsils. Every major city in my area set a record Wednesday with Moline leading the away with a high of 95 degrees. Add a dew point of 73 and the heat index (how it felt was 103 degrees!) May 11th, are you kidding me? Here's the records established in my area Wednesday vs the old benchmarks. The record broken in Dubuque had stood for 143 years old. Mercy, that's impressive.
MOLINE.................95 (91, 2011)
DUBUQUE.............92 (90, 1879)
CEDAR RAPIDS....91 (90, 1922)
BURLINGTON.......91 (91, 2007) Tied
As I've mentioned before, it's not rare to get into the 90s in May, especially later in the month. What is unusual is to see those temperatures with dew points (water vapor/humidity) in the low to mid 70s. Most of our early season warmth comes with windy dry air masses. Dew points in the 40s and 50s. Wednesday we didn't even have the wind to provide relief. As you can see in this NWS graphic, the dew points we've experienced the past couple of days are borderline oppressive, something more common in June and July.
Overall, I don't see much change Thursday as the ridge that's brought the steamy weather holds for another day. Mixing should be a little stronger allowing more of a breeze and perhaps a small drop in dew points. In general though. the cap holds sustaining dry weather and highs in the upper 80s to low 90s (near records). The record in Moline and Burlington stands at 94 and I doubt they'll be achieved in those communities. However, Cedar Rapids and Dubuque are in the game where a 90 get's the job done. Heat index values in the mid to upper 90s should be just low enough to rule out the heat advisories that were hoisted Wednesday.
Changes finally begin to take place Friday as a cold front makes slow headway into the region. More clouds and possibly afternoon thunderstorms should take temperatures down a few degrees with highs peaking in the low to mid 80s. Dew points will remain close to 70 so another muggy day is in store. The warmth and moisture will create instability for the front to work on Friday afternoon and evening. CAPE values reach up to 2500 j/kg which is enough energy for marginally strong storms if realized.
SPC does have a slight risk outlook in place for Friday afternoon and evening. Personally, I don't look for much in the way of severe weather if current trends hold.
As far as rain totals go, if timing is right and instability is maximized, some good downpours are possible in the stronger updrafts. The EURO is not that enthused over amounts but the GFS and 12k NAM have a healthier look. Here's what models are suggesting for rain totals through Friday night.
The 12k NAM
Any lingering rains are out early Saturday morning and the rest of the day looks partly sunny and mild. Highs in the upper 70s to low 80s are expected . The big change will be much lower humidity in the afternoon when dew points fall to the mid 50s and low 60s. That will make a big difference in how things feel.
Another fast moving wave arrives Saturday night and Sunday morning with an associated shower chance. Amounts should be light, 1/4 inch or less in most spots. Highs on Sunday will be back to more seasonal levels in the low 70s. For the most part Monday and Tuesday's temperatures look similar and at this point both days appear to be dry.
The Climate Prediction Center's 6-10 day outlook looks like this for the period May 17th to the 23rd. I think it's ideas have strong merit and I'm comfortable with what's indicated.
With that it's time to prepare for another muggy May day Thursday. I like the warmth but a more refined sauce on my taco would work just fine. I might have to order a margarita to get through it! Roll weather everybody,,,,TS