Pick a storm…any storm: Part 1

(posted by a very sleepy and grammatically challenged Karen Kosiba)

Before picking a storm, I would like to extend my deepest sympathy to everyone impacted by today’s severe weather outbreak. At best it is scary, at worst it is absolutely devastating.

As tornado scientists, we cannot alter the meteorological conditions that produce tornadoes. We only can collect the data. We collect this data in order to improve our understanding of tornado dynamics. If we can better understand how tornadoes form, how they are maintained, and what the winds are like at building height, we can make better forecasts AND can provide engineers with the information necessary to design better buildings (this sentence contains a lot is a lot of “betters”—I know! I could have used “gooder”, but, for some reason, Word chose to reject this “Word”).

Today was tricky.

Let’s talk about the forecast:

1. Today's severe weather event was well forecast (which means that the more predictable ingredients for severe weather had been evident in the model runs for several days).

2. Conditions were favorable for severe weather over a broad region (500 miles may not seem like a lot, but that is a solid 7 hour drive, and with 40+ vehicles—Oi!). Since conditions were favorable over a broad region, many storms would form. But which of these would be tornadic?

3. Given the meteorological conditions, storms were forecast to move FAST (fast is bad, because that means we cannot “chase” the storms. Instead, we need to pick a location to sit, wait and let the storm(s) overrun our instruments. This is limiting because it is difficult to adjust once we are deployed).

4. The region that was most favorable (meteorologically) for long-lived tornadoes is full of trees and hills (which is bad for collecting radar data because the trees and the hills block low-level radar scans).

That was the forecast. Let’s talk about the deployment (i.e., strategy):

Given that the storms were forecast to (a) move fast and (b) occur in a regions characterized by less than desirable terrain, it was decided that the radar teams would survey an area that roughly comprised most of northeast Oklahoma in order to find locations suitable for radar deployments. The task was divided among 3 teams. This meant that each team spent 3+ hours (on the day of the severe weather outbreak) driving up and down roads looking for sights that were relatively flat and unblocked (very few trees) so that a radar could collect relatively unobstructed data. Ultimately, we needed 6 sites (for 6 different radars), but because there were no storms yet (this was about 1100, storms were not forecast to form until ~400), we needed to find a bunch of sites (roughly 10 billion--or maybe it was just 70??--one loses track after 3 hours) that would accommodate a multitude of storm scenarios (what if the storm forms here and moves this way…? what if the storm forms there and moves that way…?).

How does the rest of the day unfold for Vortex2?

Stay tuned... (I will say this much--we were/are in Oklahoma)

A “better” blog to come (Part 2)—I literally am in the dark tonight. Our hotel has no electricity, so I am in the DOW running the generator. I imagine most of the hotel patrons do not equate the sweet hum of the generator with a sweet lullaby at 200 AM...

Picture 1: 700 A.M. on 10 May in Perry, OK. The calm before the storm (hmmm…i get it!).

Picture 2: A picture of my computer screen (who takes pictures of their computer screen?!). It is the Storm Prediction Center's outlook for the probability of severe weather today. Severe weather is probable today (yes. I concur).