05.11.10
Posted in Uncategorized at 11:01 pm by Rebekah
I posted a lengthy chase log on my website, so I won’t rehash the whole story here.
Long story short, we saw two brief tornadoes, near Sand Creek, south of Wakita, Oklahoma (where the film Twister was filmed).
Chase photos and video will be posted soon, but unfortunately I don’t have much footage of the storms and tornadoes as they were moving so fast (and the tornadoes were so brief).
Here’s probably my best photo of the first funnel cloud we saw (click to enlarge), that became the first tornado (there wasn’t a full condensation funnel, just this funnel plus a debris cloud).
And here’s an image of what the radar looked like shortly after the tornado, while it was producing yet another, longer-lived tornado (note the pronounced hook echo). The white dot and circle indicates where we were at the time of the radar image.
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05.10.10
Posted in Severe Weather Forecast at 9:22 am by Rebekah
SPC Day 1 Convective Outlook
Hmm…where to start. The first High Risk on the Southern Plains since April 26th of last year, and the third High Risk in less than two weeks. The SPC has the tornado risk at 30% hatched, meaning there’s the potential for EF2 or greater tornadoes within 25 miles of a point.
A shortwave trough is fast approaching and is expected to be over central Kansas / northern Oklahoma by evening. A surface low will move across southern Kansas today, as a warm front lifts through Oklahoma up into central Kansas. A dryline will tighten over west central Oklahoma by late afternoon/evening (NAM dryline keeps pushing back west…something to keep an eye on…), when a narrow band of 70F dewpoints is forecast to stretch north through central up into northeastern Oklahoma.
CAPE of 3000 to 4000 J/kg is expected along the dryline, from northeastern Oklahoma southward all the way to San Antonio. Mid-level lapse rates will be very steep in this region, approaching dry adiabatic.
With south-southeasterly surface winds in central into eastern Oklahoma and southeastern Kansas (the NAM shows better backed southeasterly winds in north central/northeastern Oklahoma and southeastern Kansas, ahead of a dryline a bit farther west of the GFS), and west-southwesterly winds at 500mb, shear profiles will be more than sufficient for rotating storms. The NAM shows 0-1 km storm-relative helicity values of over 100 in most of Oklahoma (ahead of the dryline), with over 400 in northeastern Oklahoma into eastern Kansas and Missouri (0-3 km SRH is over 300 in Oklahoma and over 500 in northeastern Oklahoma into eastern Kansas and Missouri). Soundings and especially hodographs appear to be textbook for classic supercells in much of Oklahoma (from I-35 east) and southeastern Kansas.
Everything appears to be coming together for a major severe weather outbreak from central into northeastern Oklahoma and southeastern Kansas (although severe storms are certainly possible all the way south along the dryline into west central Texas). Without much of a cap (GFS shows a stronger cap, but it shouldn’t be much of a problem–if anything, it could help stronger, more isolated storms to form), it looks as if there will be supercells with large hail and strong tornadoes from central Oklahoma into southeastern Kansas (and possibly southwestern Missouri near/after dark).
A few early showers in northeastern Oklahoma and south central to southeastern Kansas could set up a few outflow boundaries to assist in storm development later in the day.
Storm motion could be a problem as far as chasing goes, today, as the storms will be moving fast (near 40 mph) through an area with some trees and not the best road network.
Nevertheless, I will be out there streaming today (see my tracking page on my web site), somewhere in north central to northeast Oklahoma. VORTEX2 is already up in the area, hoping to finally record some quality data, hopefully in rural areas.
My target area for the last couple of days has been Ponca City, Oklahoma to Arkansas City, Kansas. If the NAM comes closer to verifying on the dryline than the GFS, storms may form farther west in north central Oklahoma / south central Kansas…however, as storm motions will be pretty fast, it would be better to stay ahead of where I think the storms will form, so I don’t have to play catch-up as much.
I think for now, I will target Blackwell, Oklahoma. I’ll discuss with my chase partners, Jeff and Esther, within the next hour, to see what they think, and then we’ll probably head out around 10:30 to 11 AM…
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04.30.10
Posted in Weather News at 11:16 pm by Rebekah
The Storm Prediction Center started off the morning by issuing a Slight Risk for severe thunderstorms, but has since upgraded to a High Risk, centered in Arkansas.
A line of supercells, now merging into more of a squall line, is marching across parts of the Midwest into the Mississippi River Valley area, putting down numerous tornadoes from Wisconsin to Arkansas (see the radar image, above; tornado warnings are small red boxes, while tornado watches are larger red boxes and severe thunderstorm warnings are are in blue).
Ample CAPE and wind shear have been conducive to rotating storms in this general area, along a cold front, for most of the afternoon.
Sadly, there have already been reports of deadly tornadoes in Arkansas. Tomorrow, the storms will progress towards the Southeast, giving the already tornado-weary Mississippi and Alabama another chance for severe storms.
The low that is responsible in part for this severe weather may be the last one we see for a while, on the Plains anyway. Models for at least the next week show primarily zonal flow across the US, meaning no big troughs to assist in producing strong thunderstorms.
Right in time for VORTEX2, which starts up tomorrow…
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04.29.10
Posted in General News at 9:14 am by Rebekah
Well, I got my laptop back Monday night, but found out on Tuesday that it takes much longer to start up than it did before, and it won’t come out of standby. I did manage to back up the few files that I had not backed up since the last update, including a few website files. So although I took my laptop back to Best Buy yesterday, I should be able to manage doing some website (and blog!) work now…although I am still pretty swamped, so time spent on both may be limited until towards the end of next week (the end of the semester, woohoo!).
The first thing I did was update the photo of the week (it’s a tornado) and the “this day in history” blurb on the front page.
When I did that, I noticed that this older computer messed up the color scheme a bit, and I haven’t been able to figure out how to fix it yet. My problem is that I want to have hyperlinks in blue, with the exception of the hyperlinks overlaid on the dark purple tabs on the left side of each page. I didn’t have a problem with it with Vista (now I’m back on XP), so I may just have to wait to fix once I get my newer laptop back. In the meantime, I tried to keep the white hyperlinks on the front page, while highlighting anything else that should have been blue. When it came time for the chase pages, though, I just left them as is…for now.
I also went through my chase photos from Thursday and picked out a grand total of 45! That’s something else I want to eventually do for the website–find or create some sort of slide show program, where everyone can click through the large photos (kind of like Webshots does it)…rather than seeing the thumbnails and having to click on every one you want to see. Anyway, that’s for the future.
I did post the chase log and photos for April 22, so you may want to go check that out–there are lots of tornado photos!
I also took some HD video, but as my disclaimer on the photo page says–I couldn’t post HD quality. I use Windows Movie Maker to edit videos, so I wanted my raw video converted to WMV. When that happened, it was degraded to standard definition. The video was then further degraded when I saved it from Windows Movie Maker. So what I uploaded to YouTube is not the original video–the original is clean and sharp. I will have to find a way of posting at least higher quality video, if possible. For now, I don’t have the time to mess with it, especially as I’m wrapping up stuff for the semester.
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04.24.10
Posted in Uncategorized at 10:48 am by Rebekah
The Texas target verified on Thursday, and I saw my first tornado of the year! It occurred out in the middle of nowhere, and according to the NWS it only damaged some power poles. It was the strongest, most long-lived tornado in the panhandle that day (not including the wedge near Childress around sunset), rated at EF1 and lasting 20 minutes.
I will write up a full chase log and post photos and video on my website hopefully later this weekend (probably Sunday evening or Monday), but here’s a teaser:
EF1 tornado on 22 April 2010, near Goodnight, Texas (click to enlarge).
Now I’m off to Catoosa (just northeast of Tulsa) to attend a memorial event for the seven victims of the 24 April 1993 F4 tornado, the strongest tornado to ever hit the Tulsa area. A 35-foot-tall metal tornado statue will be unveiled, and a large electric motor will cause it to rotate. I’ll post pictures later today or tomorrow.
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