Friday, May 16, 2008

Surprise rain storm lashes Lafayette

There really is never a dull moment when it comes to our weather in the Midwest. Remember for every stormy day in Lafayette, we average two sunny days. But sometimes when it rains it pours. Out of the dozens of models I use to forecast every day there was less than a 5% chance that we would end up with more than one inch of rain. Remember this is a field of probability and things can go wrong in a hurry. We had about 10 days worth of rain in 7 hours. How does it make me feel when I get one wrong? Nobody feels worse. Yes, I take it very hard and I will not go home until I find out what I could have done better. So what happened? Take a look below.

At 10,000 feet we had converging winds over our viewing area. The winds literally met overhead with northerly winds meeting southerly winds. This caused the air pile up over our area and it had nowhere to go but up. This rising air quickly condensed and cooled bringing us heavy rain at times and a very soggy evening. Adding to the mayhem, we also had an upper-level low pressure come farther north than expected adding even more lift as you see below. Sound familiar? I still blame the ghost of our winter pattern and the La Nina. The La Nina is hands down the toughest pattern to forecast not only here in the Midwest but throughout the world.
This low pressure behaved more like a storm system we would see during the winter. The winter of 2008 is still hanging on at least in the middle and upper levels of the atmosphere. Unbelieveable! It is the winter that will not go away! Our freezing levels were at only 7,500 feet which is unusually low for this time of year. This allowed for incredible ice crystal growth in our clouds and these ice crystals stuck together and melted as they descended upon the land of the Wabash. This caused a phenomenon called "bright banding" on our radars. This melted water gives these ice crystals about 10 times more reflectivity than they normally have and it makes them look like almost alien or humongous raindrops. This is why some doppler rainfall estimates were in the 4 to 6 inch range for rainfall last night. The good news is that most of us had between a half-inch and two inches of rain. Our weather watchers get the gold star for the night by keeping me updated and then I could relay this data to the National Weather Service. We would have been in huge trouble if we paid attention to the doppler estimates below.

The deep red or crimson and light purple from Benton County through Miami County indicates a huge swath of 4 to 6 inch rains. This was caused by the "bright banding" or the radar beam picking up tons of melting ice in the lower parts of the clouds. We would have had another significant flood on the Wabash, but the good news is that I spoke to Sally at the National Weather Service tonight and here is what I found. Al Shipe the State climatologist said that an inch or two of rain which we really received would still only cause minor flooding. NO MAJOR FLOODING IS EXPECTED ON THE WABASH! The rainfall we had last night would not really act to raise the water levels as much as it would keep the water out of its banks longer. This will keep the Wabash River in the minor flooding range. The bottom line is the crest on the Wabash at Lafayette should be no higher than 15 feet early this weekend and then it will slowly fall below flood stage next week. This is good news for River Lover and all those that live near the Wabash.

Our blog question of the day? What if last night's rain would have been snow. How much would we have had?

We would be digging out for a couple days that is for sure. I would be in snow heaven with all the other snow lovers. But tonight on the news I have some real Spring weather and maybe even some 80s in the extended forecast just in time for Memorial Day weekend. I will also let you know if nature has any more surprises it will throw our way this weekend. I still think you should not cancel any plans and I will tell you why tonight. Have a wonderful day and thanks for sticking by me even when the weather takes an unexpected turn. We all know who is in control and it certainly isn't me.
At least we have this blog to help us all understand why a forecast has changed and at the same time it helps keep everybody not only more informed but much safer. That is what it is all about!


Anonymous said...

Everybody calls 'em wrong sometimes. Keep up the good work! Your blog always makes me smile in the morning!

Renee said...

I agree and that weather can always be misperdicted.
I dont think it makes you any less for being wrong, you cant be perfect so dont worry and try not to feel bad.
So far it looks very nice out today,thank goodness. And did I read somthing about 80s...that would be great so that we could get into those outside pools.
Enjoy the day.

Anonymous said...

Don't feel bad this is indiana and are weather changes in a heart beat. But with this LA-NINA still lingering around dose that mean we could have another snowy winter?
I love snow. But for now some warm weather would be good so we can get are pool open.

Justin in lafayette.