WHAT IN TARNATION...
WE DOGGIE, we have entered the fire! Jethro, show me the cement pond. Smoking temperatures ruled the day Tuesday with highs in most areas in the upper 80s to low 90s. The NWS in the Quad Cities reached 91, just two degrees short of the record set back in 2011. This year was worse though with a dew point of 72 creating a heat index of 97 degrees! A few places clipped 100 as you can see in the 4:00pm apparent temperature readout below. That is mighty impressive for May 10th, especially considering the radical change from weeks of below normal temperatures. What in tarnation is going on?
You'll notice it was a different story though in the NW half of Iowa where a stationary boundary was keeping both the heat and humidity at bay. Here's the 4:00 temperatures showing readings only in the 70s NW of the front.
The front became the focus for thunderstorm development Tuesday night in NE Iowa and Wisconsin. Modeling indicated some of those storms drifting into my area overnight. However, a stout cap has hindered that process and so far I don't see much on radars at the time of this post. While scattered storms may end up clipping some of my northern counties indications are they will have dissipated (or will be in that process) by daybreak Wednesday.
The leaves the region in a position where more unseasonal hot humid weather will prevail Wednesday and Thursday. Highs both days should reach the upper 80s to low 90s, near but probably just short of records. Dew points will remain exceptionally high by early May standards in the low to mid 70s. Heat index values will again be significant in the low to mid 90s.
For the most part, forcing is lacking (or capping is prevalent) which should limit any thunderstorm development Wednesday and Thursday despite a very unstable atmosphere. Not to say a stray storm or two won't pop up but they look very spotty with the greatest chances (30% or less) in the north and west.
Friday or Friday night, thunderstorm opportunities increase as a front slowly inches into the area. I do look for scattered storms but how widespread the coverage turns out to be is in question. Some localized downpours are likely in the stronger updrafts with high levels of water vapor in place. At this point, dynamics are not overly impressive and the severe weather threat seems low. Here's what models are suggesting for rainfall Thursday through Saturday. This may be on the high side.
The Weather Prediction Center
The last of any showers and storms will depart the region early Saturday leaving the region with another warm day. That said, highs should be about 10 degrees lower leaving us with highs in the upper 70s to low 80s. Another front zips into the region producing another chance of showers or storms late Saturday night or Sunday morning. Cloud cover could keep highs Sunday in the upper 60s to low 70s which is pretty typical for mid-May.
Next week promises to be far more seasonal as the pattern transitions to more of a west northwest flow aloft. That will put a big dent in the warm temperatures and high humidity. Temperature departures the next 5 days (May 11th-May 16th) look like this.
Note the following 5 days are decidedly cooler with departures May 16th-May 21st looking like this. It's bye bye summer as spring regains the upper hand.
Well, the air conditioner is on for the first time and it looks like it will remain on the rest of the week. Nothing like going from the heater to the AC in the blink of an eye. Here's to the great Midwest! Roll weather...TS