Forecast: Humidity builds, maybe a t'storm Sunday

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Today's Daily Digit

 

A somewhat subjective rating of the day's weather, on a scale of 0 to 10.

 

Summer-like warmth and sun feel good, but taste of humidity an unwelcome preview of Sunday stickiness...

 

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EXPRESS FORECAST

Today: Mostly sunny and very warm. 85-89. | Tonight: Partly cloudy and muggy. 65-70. | Tomorrow: Very warm and humid. 30% chance of t'storms. 86-90. | A Look Ahead | Get Express Forecast by E-mail

FORECAST IN DETAIL

On the handful of very warm to hot days we've experienced so far this spring, we haven't had to contend with much humidity. That won't be the case this opening weekend of May. What is a hint of humidity today grows to typical July levels Sunday. And with all the juice in the atmosphere, we'll have the risk of some scattered late afternoon and evening thunderstorms.

Today (Saturday): While the humidity becomes palpable today, it won't be oppressive (dew points in the low 60s). In fact, I think many people will find today's conditions quite enjoyable. We'll have a lot of sunshine and highs in the mid-to-upper 80s. A pleasant breeze from the south at around 10 mph should compensate some for the humidity. Confidence: Medium-High

Tonight: I can't entirely rule out an isolated evening thunderstorm (15-20% chance, mainly in the northwest suburbs), but most spots should be partly cloudy and dry overnight. The humidity will keep rising, making for a muggy night. Lows will range from the mid-60s in the cooler suburbs to just 70 downtown. Confidence: Medium-High

Keep reading for the forecast through early next week...

Tomorrow (Sunday): This will be the first legitimately "sticky" day of 2010. Highs will be in the upper 80s to near 90, but factoring in the humidity, it will feel like the low 90s or a little warmer. The combination of humid air and a front slowly approaching from the west could set off a few scattered thunderstorms (30% chance), though the better odds will be on Monday. Confidence: Medium-High

Tomorrow Night: Scattered thunderstorm chances (30-40%) continue into the evening and overnight period. Lows range from the upper 60s to around 70. Confidence: Medium

A LOOK AHEAD

As a cold front passes through Monday, there's a slightly better than 50/50 chance of showers and thunderstorms. Otherwise, expect partly to mostly cloudy skies, with highs in the low-to-mid 80s. Clearing and modestly cooler overnight, with lows in the upper 50s to low 60s (suburbs-city). Confidence: Medium

Abundant sunshine returns Tuesday along with lower humidity levels. Highs should range from 75-80. Confidence: Medium