Cristobal: Size Matters

Cristobal is expected to eventually cross the western Great Lakes
and go into Canada later this week. 

Tropical Storm Cristobal, which came ashore in Louisiana Sunday proves that "weak" tropical systems are anything but.  

Top winds with this thing were 50 mph, which doesn't sound like that big of a deal.  However, what Cristobal lacked in wind was more than made up for in size.

Cristobal didn't have a classic tropical storm shape while it was in the Gulf of Mexico.  In satellite photos, it looked more like a giant comma, like you would see in a strong nor'easter in coastal New England during the winter.

Tropical storms and hurricanes usually have a more circular, symetrical shape.

The tropical storm was large in size, which meant it could cause havoc over a wide area.  That's why you saw on the news tornadoes swirling through Orlando, Florida. It's also why parts of Florida got up to a foot of rain.

Size mattered in an even more important way.  Cristobal's relatively modest winds covered a wide are of the Gulf, so it was able to push a lot of water ahead of it.

This created a nasty storm surge, made worse by the timing. The surge came just as high tide rolled in.  Coastal communities like Grand Isle, Louisiana and Waveland, Mississippi were inundated as a result .

MORE CRISTOBAL TROUBLE

Cristobal, now a tropical depression as of early this Monday morning, will move generally north and end up in Wisconsin by early Wednesday morning. It will take a swath of heavy rain with it. Flood watches are up along the projected path of Cristobal in Mississippi, Arkansas, Missouri, Iowa and Wisconsin.

The storm will be gradually becoming a non-tropical system as it moves northward through the Midwest. If it still has some tropical characteristics by the time it hits Wisconsin, which is quite possible, that will be something.

The storm is actually expected to strengthen as it approaches the Great Lakes as it gradually merges with another storm.  It could cause some damaging wind gusts midweek, and create the lowest air pressures on record for June in that area.

VERMONT EFFECTS

We won't have any direct impacts from Cristobal here in Vermont, but it sure is helping to make the weather forecast challenging.

The Cristobal storminess in the Midwest and a strong, but sharp and narrow upper level ridge further east puts Vermont in a weird spot.  A warm front out ahead of everything will try to move in, but there's disagreement in the computer models as to whether it will make it all the way through here.

High and mid level cloudiness will accompany this feature over Vermont Tuesday, and a pretty big temperature gradient will be setting up over or near Vermont.  We could end up with  a cool, cloudy 65 degree day up in Newport and a muggy 85 degree afternoon down in Bennington.  That's just one possibility, but the temperature contrast could set up further west, or further east. Who knows?

Wednesday's weather is a toss up. It all depends on where that warm front goes, and if it makes it north of us. It could either be humid and way up in the 80s to near 90 in a spot or two, or just in the 70s with more moderate humidity.

Amid all this uncertainty, the remains of Cristobal, and the cold front it will eventually drag through here at the end of the week, won't give us a lot of rain.  Which is too bad. We still need it, despite the showers we had over the weekend.

Here's a drone view of storm surge flooding from Cristobal in Grand Isle, Louisiana: