Severe Weather Southern Plains:4/14/11

Hey Chasers and blog Followers, Figured I would update everyone on the severe weathe situation forthcoming tomorrow afternoon/evening across the Central/Southern Plains. I realize that probably none of you will be able to chase this event tomorrow, but it does look like a quite favorable setup, even a classic type event.

**UPDATE 7:30am 4/14/11**
After looking at latest data and model guidance have shifted my target area to get to this afternoon a bit farther South and East. I will be working until 2:30pm CST and then plan to head out right after. Will be taking Rachel with me as she is a good luck charm, and can drive. This way I should be able to get better video and continue to analyze latest obs, radar, etc. Back up base support would still be great if anyone has some time in the 3pm-6pm time frame. Yesterday I had mentioned the Wichita, KS area and while I still think storms will initially fire in that area Surface dryline/encroaching coldfront will occlude with warm front faster to the West, will plan to target the Neodesha, KS/Coffeyville, KS, Nowata, OK area. Would like to get to > 60s Td and be South of the leading edge of warm front area. Will update again one more time this afternoon before I head out if things change. Can already here the Twister theme song playing in my head, :)

Synoptic Setup:
A potent 30omb negatively tilted trough will dig its way Southeast across the Central Rockies late this evening into tomorrow afternoon over the SW Great Plains region. Attendant riggourous 500mb shortwave will eject over the region between 18z-00z tomorrow afternoon/evening. GFS, ECMWF, and WRF are all pretty much in line with the upper level pattern yielding a broad area of synoptic ascent from exit region of 100kt 300mb jet leading the upper level trough axis. A very focalized area of upper level diffluence resultant of the negatively tilted trough should also aid in strong upper level forcing over the region in question (This is exactly what I look for at upper levels in a classic severe weather outbreak setup). At mid levels SW flow at 700-850mbs will advect a strong EML with > 8K/Km lapse rates out ahead of the system across the dryline region of the Southern Plains this afternoon/evening into tomorrow morning. At low levels a deepening sfc low will develop to the Lee of the Southern Rockies and trek across Southern CO/Northern NM later this evening into tomorrow morning. As this system strengthens strong southerlies out ahead of the sfc low will pull low level moisture up across the Red River valley into Central OK and Southern KS. A distinct warm front and dryline setup will be in place across the region by 12Z-18Z tomorrow with lagging cold front drapped back across eastern CO.

Mesoscale Setup and Severe Parameters:
This pattern will promote the classic Sfc Low, Dryline, Warm Front triple point severe weather setup. Sfc forcing associated with deepening low and warm frontal lift will aid in elevated convection developing in the early to late morning hours across Eastern CO, Western KS, and SW NE. Afternoon heating and subsequent mixing out of BL should cause afternoon bulging/advancing dryline to act as the initial focal point for surface based convection to form. Uppper level cooling and forcing will further help to destabilize warm sector by later afternoon. Forecast ML CAPES across the warm sector should be 1000-1500 J/kg over South Central KS to > 2,000 J/kg across central OK. 0-6km bulk shear values over 40kts across the area in question will promote the development of Supercells. Backed flow at the surface and veering profiles with height will promote right movers as storms split and move ne into very favorable conditions for rotating updrafts and potential tornadoes. Look at any progged sounding in the warm sector and you will easily see what I'm talking about.



The "GO ZONE":
Based on what I mentioned above, my game plan is to head down to the Wichita area to be on the dryline for initiation) and wait for surface based storms to develop and move into the more favored zone for tornadic development. I think there will be a pretty large area for severe weather extending South along the dryline and eventual cold front overtaking, but want to focus on storms along the OK/KS border that will move into my favored area in red above. My main concern with tomorrow is BL moisture. Given the lack of time for return flow from off the gulf, I think > mid 60's Tds will be very difficult to get all the way into Central KS. 12z Model guidance shows a narrow tongue extending up from Central OK into Extreme Southern KS by 00z. Hoping Td depressions will not be too large to get ground circulations. That being said though, steep lapse rates and adequate CAPE values will lead to large hail potential with most storms especially as you head south, but also will promote very strong downdrafts due to the EML. Thinking that may be enough to overcome moisture shortcomings and get some of these funnels to the ground.

Fearless Fantasy Forecast: o/u 12 tornado reports, 45 hail reports, 30 wind reports

Let the games begin and I'll do my best to keep the "tor" streak alive and get some great pictures/videos for the blog. I'd love to hear anyones thoughts on the setup for tomorrow and I'm pretty sure SPC is going with a MOD risk as well. It's always good when we can agree on potential.

Happy Hunting,

Dan aka Squall Line