Tuesday, October 26, 2010

Feeling Cheated by the October 26th 2010 Storm of the Century? (updated)

Feeling that this "record storm" didn't live up to its hype? Wondering why the news and weather geeks such as myself were going so bonkers over it? Sneering at the fact that you secretly wanted  to see destruction and chaos and upset it did not materialize? Wondering just what in the hell was the big deal? Well, here we go.

The storm was forecast to be a record breaker, as I mentioned in my previous blog. Well,

- Chicago set a new low pressure record. At 7am the barometer plummeted to 29.02in, old record set in 1959 was 29.11in

- But perhaps the most important record of all. The all time, new, lowest barometric pressure ever recorded in any non-tropical storm system to form in the US mainland. The low made it down to 956mb with some unofficial reports of it going just a tad lower. Thats not a lie, although the data is still preliminary so I don't know of any official statement yet which I can post.

*Weather 101 fact for the non weather savvy - the lower the pressure, the stronger the storm system.*

So, when you hear "strong storm system" here is what they are talking about.

To put it into perspective, most storm systems don't go below 990, most stay around 1000. So 954 is INCREDIBLY strong. So when they are talking about a storms strength, its that pressure they are referring to.

To those who feel that they were cheated and the storm did not live up to its hype, you were just that, cheated. Especially for my friends in the Chicago area. The fact of the matter is the timing of the storm system is what spared us its greater wrath. The storms formed along the storms advancing cold front. Which happened to plow through here just after dawn. This, and this alone is the sole reason why severe weather wasn't more widespread across the Chicago area.

*Weather 101 fact #2 - Storms need energy to become severe, the main source of this energy is the sun, thus, at night and during the morning there is the least amount of energy*

The predawn hours are the LEAST favorable time for severe weather, and sure enough, thats when the front came through this area. Normally severe weather would not be forecast at all when the timing is such, but again, we were dealing with a record strong storm, which can sometimes offset the lack of energy, and it did. We did get storms and severe weather in the early morning hours, it just wasn't widespread.

So here is some of the evidence of severe weather occurring in the area.

Tornado damage photos near Peotone, courtesy of Dave.

This one is too awesome not to share.

Closer to home, some tree damage in the Chicago and Oak Lawn areas. Taken by myself and my father-in-law.

Here is a radar shot I took showing the storms moving through, the white box is actually a tornado warning just south of the Chicago area.

As mentioned though, the fact the storms came through in the early morning during the least favored time is what kept it from being more widespread. As the storms pressed east and the day got later the magnitude of the event can be seen in the amount of damage reports in the following graphics.

Ok ok you get the point. The event was a significant one, and because it is still ongoing much more information has yet to come in. Everything above is preliminary and maybe I will post a followup with some official totals but the bottom line is this.

If you feel cheated by this event, you should. It did indeed do everything it was supposed to do but remember this. Severe weather in itself is a rare and isolated phenomena, it can greatly affect your block, and leave the next untouched. So don't worry, your time will come. No one location can dodge the bullet forever.

For the latest information, see the NWS in Chicago: http://www.crh.noaa.gov/lot/

UPDATE 10/28/10 - it now appears the storm DID NOT break the record, but nearly missed it by a measely .2mb. It looks like a stupid nor'easter still holds the top title: http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=lot&storyid=59038&source=0

1 comment:

Bob Hartig said...

Good post, Adam. Bill and I chased the line in northwest Ohio. Frankly, it was at that time and location just a good, old-fashioned Great Lakes squall line, albeit attended by some incredible low-level helicity. What impresses me is the number of tornadoes generated in an environment with minimal instability. I don't know what the CAPE was in our area, but I seriously doubt it was more than a couple hundred J/kg at best. Had we gotten, say, 1,000 J/kg, I think we'd have had something really awful on hour hands. I've studied the 1965 Palm Sunday Outbreak; Tuesday's wind fields were comparable and the low was much, much deeper.