5/4/07 FCST: KS/OK/TX

[Michael O'Keeffe]

This may be a bit premature, but i noticed there hasn't been much talk on Friday, May 4. Tds exceeding 70F and CAPE over 4500 j/kg will be present from SC KS through C OK to NC TX. A 998mb low will be lifting into SE CO ahead of a large trough. Though weak 500mb winds are concerning at this time this day could be a huge day in the beginning of a prolonged severe weather episode that will occur this weekend.

 

[Doug Lee]

Did you see this thread?

http://www.stormtrack.org/forum/showthread.php?t=12173

It started up over the weekend, I believe. I noticed the SPC 4-8 Day Outlook has an area outlined from the PH's to Tulsa, up to NE and down into CNTL TX, mainly for days 5-7, so something has got to happen somewhere somtime next weekend. Because I'm without a working vehicle, I have to wait for the storms to come to me. I'd just about give up a body part to see a flanking line!

 

[Brian Stertz]

Looking at the cap situation on Friday...that looks like a day in which the only storms to pop will be elevated in nature well north of the warm front across N/C Nebraska...with an outside shot of some scattered surface based supercells across NW Kansas into SW Nebraska. Although the CAPEs will make one salivate...the cap looks to be very stout. Looks like one will have to wait until Saturday & Sunday before getting some legit supercells to chase...and even then it looks like a High Plains for both events given the forecasted position of the eastern edge of the main jet.

 

[Gabe Garfield]

5/4/07 FCST: KS/NE

The 12Z NAM paints a pretty picture (minus a distinct lack of synoptic scale forcing) for Friday evening.

Very rich Gulf moisture should be in place as far north as the surface low, which is forecast to be in SW NE by 00Z SAT. Additionally, NAM progs a rather strong mid-level jet streak (WSW, 40-55 kt) to enter the central Plains at the same time. Consequently, this is progged to enhance the surface low (due to compressional warming in the lee of the Rockies) and subsequently enhance low-level wind fields (due to the enhance pressure gradient caused by the deepening surface low). Accordingly, low-level shear will be quite strong over a large part of the central and southern Plains.

The major limiting factor at this time appears to be weak synoptic scale forcing for convection in the warm sector (KS will be on the warm side of the mid-level max-->no dPVA). Furthermore, the NAM shows no precipitation south of the KS/NE border. However, the trend seems to be for the trough to dig a bit further south. Not a slam dunk by any means, but certainly something that bears watching, especially with the progged extreme instability in the warm sector (>4000 j/kg of CAPE).

EDIT:
At this time, given the lack of strong synoptic scale forcing, the most reasonable target would seem to be the baroclinic zone (i.e., along the warm front) in C NE. The only limiting factor here would be the relative lack of instability (though it should be sufficient).

Gabe

 

[Matt Hines]

Agree with Brian here...cap looks pretty strong, but if anything gets going it probably would go very quickly severe. There will be plenty to see this weekend, so Friday can be put as a bonus day IF anything can go!

 

[Mikey Gribble]

Agree with the last two. The cap is going to be the killer for this day. Everything else looks great, but without a surface based storm it doesn't really matter.

 

[Mikey Gribble]

I just took a quick glance at the 00Z and it now has precip. all the way down into south central Kansas. I haven't looked very closely at anything, but if the NAM is telling the truth and storms managed to fire that far South then tornadoes would be a fairly good possibility with any storms that get going. Deep layer shear should be >45kts ahead of the front/dryline after the mid level jet comes in. With dewpoints in the upper 60's CAPE should be fairly high. Good directional shear with >90 degrees of turning. No reason to get into too much detail this far out, but conditions are favorable for supercells and everything is there for tornadoes. Not the perfect setup, but it would be a solid chase day. Now we just need it to verify.

 

[Skip Talbot]

It appears there are some significant changes between this morning's WRF run and tonight's. The surface low and everything along with it have been shifted east. The cold front is much better defined now and appears to be the primary initiator across Nebraska and into northern Kansas. The dryline takes over in central KS, but is not as sharply defined as this morning's dream forecast. Its promising to see that the WRF is firing convection further south, but the cold front is forecasted to sharpen Friday evening and sweep through overnight. I just hope storms go up on the dryline and are not undercut rapidly by a fast moving cold front. Still very nice shear with a 50 knot 500mb jet nosing in, although our low level shear would be better if the surface low wasn't pushed northeast.

 

[Rocky Rascovich]

Below is the latest run of the GFS as of 0002cdt 2May. It seems that here in okla. we'll have some capping issues which should preclude convection on this day... but with deepening cyclogenesis over the western high plains southwest GLD.. I would say between Goodland and Benklemen, NE. will very likely have a few tornadic supercells along with baseball size hail in the stronger cells. Greatest shear appears to be in this area as well.

I hope to head out if not for Friday, then Saturday... I may be on my own in my 35mi/gal Honda Civic armed with my trusty noaa wx radio, maybe my laptop if I can get it to function. Keep in mind that the links below are time sensitive before about 10Z when the new data starts coming in.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_ten_072m.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_85v_072m.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_700_072m.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_072m.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_200_072m.gif

BTW: this particular run is depicting the final blow to our drought here in Okla. for the following week... if this run materializes, we better start builkding the ark here in OKC!

 

[Skip Talbot]

Wow, does Friday look hot on the 0z run. I'd park it right off the triple point in north central Kansas where cape is over 3000, surface winds are nicely backed, and a 50 knot 500mb jet noses in. WRF has convection breaking out at 0z right in this area with the cap eroded and the LLJ picking up from the south-southeast. This looks like a classic supercell setup guys!

 

[Jim Tang]

This IMO looks to be the hotter of the two days. Setup in north central and central KS looks impressive on the 0Z NAM to say the least... backed sfc flow leading to strong SRH, 3500 CAPEs, right on the nose of the H3 and H5 jets, along with an impulse moving through, suggests likelihood for sups. Further south I'm sorta nervous about the flow being less backed at the low levels, and of course capping issues (although I still believe the cap could break along the dryline bulge in southern KS and OK north of I-40). Interesting setup to say the least, believe we could see some very nice tornadic sups in KS.

 

[Dan Robinson]

A word of caution that the WRF/NAM is considered the outlier for tomorrow given its firing of precip into northern and central KS. The GFS is showing light precip now from OKC to Wichita on Friday.

Friday looks like a high potential for a cap bust, but worth the trip in case something does go. If Friday tanks, it's no big loss as it will likely result in being in a good position for Saturday. I am going to try to make Salina as a starting point for Friday.

 

[JF Massicotte]

We are also trying to make Salina our starting poin for Friday just in case we need to go into Ne...


eems that many will be in the region tomorrow, we should meet somewhere.

 

[Shane Adams]

Barring a subsidence problem, I don't see the cap being an issue further south. I think it will be stout, but IMO it'll be helpful as opposed to a hinderence. However, I really don't care for the shear further south as opposed to northern Kansas. Still two days out, but the area north of Salina is looking sweet.

 

[Fabian Guerra]

I really like what the new nam is showing. My target will be in the vicinity of Hutchison, KS. Obvious dryline bulge there, dews in mid 60's, nicely backed surface winds, good speed and directional shear, and enough CAPE for all of us. There is a cap but, as Shane hinted, its a good thing especially with both the mid-level and low level jets nosing in sw KS by 22-0Z to act as a trigger. So far, I really believe we've got all the ingredients for a big day tomorrow. I can't miss this one...I'll be heading out tonight from Chicago.