3/10/10 FCST: KS,MO,OK,TX,AR,LA

[Adam Penney]

Began looking at Wednesday this morning, and it looks to hold some decent potential in the areas mentioned. ATTM, the 0Z NAM looks much more favorable than the 0Z GFS.

At 0Z Thursday, the NAM has surface temps in the Mid-Upper 60's across the majority of the warm sector, with 70's in NE TX into SW AR and NW Louisiana. Bulk Shear looks to be around 40-50 knts out of the SW. Storm motions would be a little rough as they look pretty speedy, as H5 winds look to be in the neiborhood of 50-70 knts across most of Oklahoma. 850mb winds look to be the most favorable in a corridor of far NE OK-SE KS-SW MO. SBCAPE certainly looks the most favorable with AOA 1000j/kg or slightly greater at 0Z across extreme eastern Oklahoma(worst chase terrain ) Td's are progged to be around 55-60 at 0Z as well. Also, an interesting area near Emporia - El Dorado,KS at 0Z, the low looks to bulge the dryline northeastward toward an area of favorable shear and ~50 degree dewpoints.

0Z GFS looks much less favorable with just about all of the parameters. 850 winds appear pretty veered, and CAPE is significantly less, along with surface temps at 0Z Thursday. I know that is very "data-ish", but thats as far as I have gotten into the setup, ATTM.

Just my eyes looking around.


Atleast worth keeping an eye on for me, after today's blown oppurtunity.


Its early Adam, Its early.

 

[Greg McLaughlin]

Just looked over 12z model data and I really like the area around ICT between 21-00z. I think we could have some decent low-top supercells on the nose of the dryline buldge under the H5 low. NAM is quite generous with instability in this area. With very steep lapse rates, strong vorticity and good surface heating it appears there is a decent tornado threat here. I doubt we can get a repeat of the long track tornado we had in OK yesterday, however I think its quite possible to see at least a couple of tornadoes under the low.

 

[Mike Smith]

I agree. The vorticity around ICT and east to the central and southern Flint Hills looks quite high. If we can get a little instability, I look for a repeat of yesterday's-type storms. Low topped convention with tornadoes.

 

[Brandon Lawson]

After glancing at the 00z NAM, the warm sector in central Arkansas has me intrigued. Pockets of up to 2000 J/KG of CAPE with some impressive shear during the 21z-03z time frame. The bigger question would be the arrival of the upper-level forcing and whether or not it can trigger convection east of the Ozarks before dark.

http://www.twisterdata.com/index.ph...nding=y&output=image&view=large&archive=false

Southeast Kansas and northeast Oklahoma are also possible plays, with the same mid-level sub -20C temps arriving, per the 00z NAM, which contributed to yesterday's surprise cyclic storm. However I'm also concerned about the lower elevation and higher LCL's (albeit not horrible) with possibly lower dewpoints. I missed yesterday, so naturally I want to redeem myself tomorrow. But that is an extreme recipe for bust. Not sure what to do.

 

[Mike Johnston]

Looks like the 00z NAM has shifted the surface features 80 miles or so to the east of the previous run, and slightly separated the surface low further from the mid-level cold pocket. Based on the earlier 12z run, I would have signed off on the distinct possibility of a "cold core" event across the southern Flint Hills of Kansas. Even so, there's still a close enough proximity between the surface low and the closed 500mb low to keep possibilities open, albeit a bit further east. Also, I like the dry punch poking up from central OK - which will hopefully be accompanied by a bit of clearing and insolation.

Looks like some hopes of a daylight target will be from Webb City, MO to Baxter Springs, KS, to Miami, OK, to Afton, OK. Not the greatest chase territory in the world, but not undoable, either. Window of time might be pretty limited, though.

 

[Bill Schintler]

Chase Target for Wednesday, March 10

Chase target:
Coffeyville, KS

Timing and storm mode:
Storms will initiate between Bartlesville and Blackwell, OK after 3 PM CST, and then build south in a broken line across eastern OK through 5 PM. The existence of a poor road network coupled with rapid storm motion is considered in the target selection, as discrete storms are likely along the entire line extending south to about I-40. Storm motion will be towards the northeast at 25 mph early in evolution, increasing to 35 to as much as 45 mph in east-central OK by 6 PM.

Discussion:
Another in a parade of shortwaves and associated cold pool aloft, currently located over AZ, will round the base of the WRN CONUS longwave trough and race towards the area Wednesday. Attendant surface low pressure will track NE from WCNTRL OK into SERN KS through the afternoon hours. A nearly stationary CF will extend SW of this feature, while a N/S-oriented DL/confluence line will sharpen across ERN OK and will serve as the focus for afternoon convection. Storms will initiate first near the triple point.

Shear parameters will support storm organization despite modest hodograph curvatures. An H7-H5 shortwave will eject from the trough base and overspread NERN OK, with SFC-H7 shear increasing to 45 kts. H85 relative vorticity of 15-20 10^-5/s E of the boundary will also aid in rotating updrafts. A potential negative factor may be LCL levels between 1000 and 1200 m AGL; however, a plume of CI spreading in from the W to locations N of I-44 after 21Z may serve to lower SFC temperatures slightly while reducing T/Td spreads.

Moisture availability is in question. 00Z SFC obs indicate dewpoints around 40F in NERN OK, and models have generally initialized a few degrees too high at 00Z. An H85-H925 LLJ will increase after 15Z, transporting an increasingly moist AMS into the area, with the arrival of moisture likely to arrive “just in timeâ€￾ by storm initiation. A -25C H5 cold pool will also arrive between 22-00Z, steepening lapse rates and increasing instability.

Further south in southeastern OK and extreme northeastern TX, SFC moisture will be more abundant although storm initiation will not take place in this area until after 00Z. Increased LLVL hodograph curvatures will support supercells early in storm development; however, storms will quickly evolve into a linear or multicell mode given the large degree of forcing and weak CIN. A mid-level dry slot will surge into that region after 02Z. Trees and a poor road network make this area undesirable for chasing.

- Bill
9:30 PM CST, 03/09/10

 

[Brendon Lindsey]

I am going to be chasing tomorrow. I am targeting Miami, OK. I will try to stay on the tip of the dryline bulge in NE, OK. I am going to keep close to the triple point if I can. Lets hope the moisture gets it way up here! I would expect tomorrow to be a better chase day than monday. If we can get 60 DP up to the OK/KS border, then we would definately have some great chances. If your going to be in the area and want to ride along or dont mind giving a ride, I am free. Oh I could use a NOWCaster too if someone is interested.

 

[Dustin Wilcox]

4KM WRF looks insane...Just check out the Updraft Helicity Values!! http://www.emc.ncep.noaa.gov/mmb/mpyle/cent4km/conus/00/mxuphl_f24.gif I don't like how drastic the changes were between the 18Z and 0Z runs, indicating the models might still not have a great handle on things...FWIW the 18Z looks WAY more awesome with the moist axis wrapping West over the cold pocket more so than on the 0Z...That being said, lapse rates are insane and even low 50 dews will likely yield some decent CAPE values, all models as of now pretty much bullseye the same region... http://ruc.noaa.gov/plots_13km_dev///cape_am_20.png

 

[Darren Wilson]

With height falls and cyclogenesis commencing over western TX, maybe the winds will back enough to get some better moisture return as the cyclone approaches. If not, I'm concerned the moisture may not be deep enough, thanks to the previous storm that does not want to move away.
As far as possible cold core goes, the models have been showing quite a bit of QPF across Northern OK and Southern KS, and with the high helicity values progged by the 4km WRF, things could get interesting with the -25 C H5 temps progged.

 

[Greg McLaughlin]

Taking a quick look at surface obs this morning I am relieved to see deeper moisture over south and eastern Texas, Louisiana and southern Arkansas. As the surface low rapidly deepens today I would expect that moisture to make a fairly quick and easy return into eastern OK and southeast KS. Also, the ground here in eastern OK is still saturated with standing water in a lot of places from Monday's rain. I am not sure how much evapotranspiration can take place in early March, but if we do manage to hit the upper 60s to near 70 I assume we would get at least a little.

Last night I was concerned about the anemic hodographs on the forecast soundings, with the largest curvature expected along the baroclinic boundary. This may be where I end up hanging out this afternoon.

 

[Chris Wilburn]

It will be interesting to see how events unfold this afternoon into early evening. I sure would like that extra hour of sun now instead of in 3 days. I noticed 61 dews in NE TX and low 50 dews beginning to creep into SE OK. The surface low is forecasted to be 991mb in very extreme NE OK by 23z. The LLJ begins to bring in more southerly winds just before noon to the NE TX are and points to the north so hopefully this will fuel some fairly decent moisture return. Most of the forecast area in NE OK appears free of precip for the most part, but blows up between 2pm and 5pm.

Target area is basically right at home in Miami, but I may venture a bit SW to catch the surface low before it gets all the way to my area. Hoping for some good surface heating free of clouds and at least some respectable CAPE, surface td's and moisture depth. The steeper lapse rates near the 500mb low and very cold temps aloft will be a good place to keep an eye on as well. Good day to keep and eye on the new SPC Mesoanalysis page. CAPE actually forecasted up to 1,500 J/kg on the RUC this morning with a small swath of SE KS near 2,000 J/kg so that's encouraging.

 

[Brendon Lindsey]

3/10/10 NOW: TX / OK / KS / AR / MO

Well, Wow. The forecast high for today is 72 in Tahlequah, OK and it is 10:30 and it is ALREADY 68 degrees. I see TQH hitting 75-78, this will increase the instability, but raise the spread inbetween temp/dew. Winds are starting to get up to 20MPH in SE Oklahoma bringing mid 50 dews along with it. I am going to head off towards Vinita,Ok around 12:30 Expecting a few storms by 4. Real question is, how much moisture and how close to the low will it be?

 

[Mike Smith]

SPC says at 1630Z, "MOISTURE RETURN APPEARS TO BE THE PRIMARY LIMITATION ON UPGRADING TO A GREATER RISK FOR TODAY." Today is going to be a test on my theory that the ground is so wet that we don't need the traditional "wide open Gulf" in order to get early-season severe weather outbreaks. I suspect we will see enough reports to have justified "moderate" risk by the end of the outlook period.

 

[Jim Bishop]

It's pretty remarkable to have another cold core tornado setup in the same state as the Monday event. For this afternoon the surface and upper features should sink up better than on Monday...the real question is the surface dewpoints. Lower to mid 40s dewpoints will support cold core supercells and brief/weak tornadoes. But if more low level moisture can advect into central to north central OK/southern Kansas, I would expect a higher chance for cold core tornadoes.

Certainly a very interesting setup with a lot of potential.

 

[jordan.hamilton]

I agree Mike, I believe this was the explanation as to why Hurricane Erin reformed over OK a few years ago. It appears to me that so far the moisture returns are going to be much better than what the models have predicted over the last several days. With the sunny skies here in SW MO this morning this should also give us more than enough CAPE and help with that moisture evaporation. I am stuck in training today at work til 4, but its looking more and more likely that I will not have to travel far from Carthage, MO.