Tuesday compared to May 12, 2004

[Chris Hayes]

I've analyzed a couple of parameters for tuesday, and compared them to May 12, 2004. If anyone cares to correct me, feel free. I got my observations from this sight. http://w1.spc.woc.noaa.gov/exper/archive/events/040512/index.html

500mb wind speeds are about the same for tuesday as they were over May 12, 2004
Cape values are forecast to be 2500-3000 over SW KS on tuesday. May 12, 2004 had cape values up to about 4000. Computer models are having a hard time grasping cape values this year, so Im expecting cape values ot be as high as 4000 across the target area
What is lacking is SRH. SRH was well over 200 over the target area on May 12, 2004. NAM is currently forcasting a bullseye of 150-200 SRH at 00z on wed. SRH is lacking but, It does appear as if some nice tornadic supercells are on the way for tuesday, if things work out as the NAM is forecasting. Hope to see a lot of you out there.

 

[Ilya Neyman]

Also May 12, 2004 had about 20kt 850 flow at 00z, vs the projected 30-40kt+ flow progged by the models for Tuesday. Furthermore the upper jet configuration was drastically different, featuring WSW-SW upper flow along with the jet core from CO NE through NE, the Dakotas, MN and into Canada. Tuesday looks to have a nice jet nose punching in out of the due west after shooting SE across the interior West, along with good upper difluence across the area of interest.

Similarities, however, are the 5/12/04 and projected 5/22/07 surface features, with a double-barelled cyclone as well as a surface low/cold front position resembling one another.

Interesting comparison.

The next week or two could be more active than what's been seen around these parts in the past several years.

 

[Mike Umscheid]

12 May 2004 did not feature a plunging cold front in the 00-06z time frame... and this was critical in maintaining a long-lived tornadic supercell on the triple point... in other words, the triple point remained quasi-stationary and the storm(s) thrived in this area. My fear Tuesday is the plunging cold front. The NAM is most aggressive with the surface front vs. GFS/UKMET (20/12z run)...thus I would suspect that the most prolific tornadic supercell would have to initiate on the dryline south of the triple point... a different scenario from 12 May 2004... it'll be interesting to see what happens... and I will likely be putting in more OT at work... I've worked every single big day so far... so gotta keep with the tune

 

[Dave Lewison]

Yes, that surging cold front may be an issue tomorrow. I don't quite remember if there was a progged surging front on 5/12/04. What I do remember about that day (besides the tornadoes) is the strong heating that was taking place north of the warm front. I believe this is what really helped keep that front from surging any further south and enabled the focused and sustained convergence along it that supported that supercell.

I remember coming down the 83 into Sublette that day. Right on the front, we were in bright sunshine, warming temps and a light easterly breeze. I knew right then that there'd be no need to go any further south that day...that front wasn't gonna go anywhere.

 

[Gabe Garfield]

12 May 2004 did not feature a plunging cold front in the 00-06z time frame... and this was critical in maintaining a long-lived tornadic supercell on the triple point... in other words, the triple point remained quasi-stationary and the storm(s) thrived in this area. My fear Tuesday is the plunging cold front.

I agree. That is my primary concern with what is otherwise a very good setup. However, IIRC, the models overdid the speed of the front on May 12, 2004 as well. Indeed, the front began to advance rather quickly near near midnight on May 12th. Hopefully, we can get this front to slow down a little bit.

Gabe

 

[Chris Hayes]

One other similarity I'm expecting for tommorow as well is the number of storms. With a strong cap in place, I expect only Isolated storms, maybe 1 or 2 to go up tommorow afternoon, probably S of DDC along the dryline until late afternoon and evening when storms fire along the cold front. I'm no meteorologist and am still learning about forecasting, but that is my forecast.

 

[Jim Tang]

One other problem that I see, besides the surging cold front, is the weak upper level winds. May 12, 2004 had upper level winds of 40-50 kt. If the slower NAM solution is correct, the stronger winds at that level will be lagging.