Severe storm threat continues Thursday

Highs in low 80s


DETROIT – Thunderstorm chances ramp up this afternoon as a cold front approaches.

Strong to severe storms are possible and, once again, this is not a "slam dunk" severe weather situation.

Allow me a moment to explain: to get severe storms, you need violently rising parcels of air. There are two ways to get air to rise violently -- either having a very unstable air mass from the surface well up into the atmosphere (meaning the air is light and easy to lift), or a less unstable air mass but with very strong physical dynamics to mechanically force the air violently upward.

In today's case, we'll have an unstable atmosphere, but probably not massive instability (this would change if we get large amounts of sun and warm up more than expected).

However, we have some pretty good dynamics moving in. So we have a conditional severe weather risk, with the most likely impact being damaging wind gusts if these storms are able to organize.

A short time ago, the Storm Prediction Center downgraded our severe risk into the "marginal" category. This does not mean that severe storms are not possible. Rather, it means that any severe storms that do develop probably won't be widespread.

As I mentioned earlier in the week, our ground is saturated, which has softened the base that our trees have a foothold in. So I'm concerned that strong wind gusts may be more effective in uprooting trees.

IF any warnings are issued, please take them seriously. Even if we don't get severe storms, "regular" thunderstorms with dangerous lightning are likely, so stay alert.

Don't forget to download the FREE Local4Casters weather app if you haven't already -- it has a great radar display that lets you see current radar here, and anywhere in the country (you can zoom and pan the map with your finger).

Also remember to follow me on Twitter at @PGLocal4 for any breaking weather updates.

Sticky highs today probably reaching the low 80s (28° Celsius) unless we get extra sunshine, which would push us possibly into the mid 80s. Southwest wind at 10 to 15 mph. 

Storms end early tonight, with lows in the upper 50s. 

Mostly sunny, less humid, and cooler on Friday, with highs in the low to mid 70s (that sounds cool by summer standards, but remember that the sun's rays are VERY strong right now…you'll need your sunscreen on Friday if you'll be spending any extended time out in the midday sun).

Mostly clear Friday night, with lows in the mid 50s.

Increasing clouds on Saturday, with a possible shower or thunderstorm toward the end of the afternoon (I think the morning and most of the afternoon hours will be dry). Highs near 80.

Warmer and more humid with a chance of showers and thunderstorms Saturday night. Lows in the upper 60s.

Showers and thunderstorms are likely Sunday morning ahead of another cold front but, as long as the front comes through midday (as today's computer models suggest), we should see some developing sunshine at some point Sunday afternoon…our late afternoon / evening barbeques and golf games should be in good shape. Highs in the low to mid 80s.

Partly cloudy Sunday night, with lows in the low 60s.

The weather for Ford Fireworks day on Monday is very uncertain. While we'll have high pressure over the Great Lakes, remember that our atmosphere is three-dimensional, and that things happening aloft control much of our day-to-day weather. In this case, a weak upper level disturbance will cross Michigan and, if we are unstable enough, it could trigger showers or thunderstorms.

Two models that I've seen early this afternoon suggest that we'll see some showers and storms, but also that they'll move out of the area by evening for the big show!

I'll definitely keep a close eye on this scenario. Highs near 80, with temperatures falling through the 70s in the evening.

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