3/31/07 FCST: TX, LA, OK, AR, MS, MO, IA, IL

[Michael O'Keeffe]

I can't freaking leave till 1pm, but I will be in Independance so that is further north than where I live. I will just blast north on I35 and hope to see something on the drive. I think setup has potential to be intertesting, I'm not a huge fan of low instability setups though, but that can be overcome. I'm liking the clear slot that is moving into the region as well.


Good luck to everyone today and stay safe!

 

[Scott Weberpal]

At 9:15 AM CDT, the dry slot has made its way into the western 1/3 of MO. Most of MO should be under the influence of this dry slot by 18-19z. I like the area near the sfc trof/warm front intersection between 18-21z. I can't chase into W. IA so I'll take what I can get here.

 

[Ryan Pfannkuch]

4-county-block target area in W IA: Carroll, Greene, Audubon, Guthrie
Including the cities of: Carroll, Jefferson, Audubon and Guthrie Center

Can't add much more than Brian and others already have, but have done something very rare here and included my current physical location of Manning, IA in my 4-county target area for this afternoon.

Can't say I'm overly thrilled with my first few glances at the dry slot on vis sat...not much widespread clearing so far...but both the 9z and 12z RUC maintained very favorable surface features for possible mini-supercell development in an arc from western to central to southeast IA. At 21z, RUC has a deepening 994mb low just north of OMA, with a fairly well defined warm front/wind shift line running right down Hwy 141 towards DSM and then southeast toward OTM. I'm gonna favor the western 1/3 of this corridor to keep a little closer to the main sfc low and cold pocket aloft.

IF there is any legitimate clearing today across this frontal region...I would fully expect at least a couple tornadoes reported today. The synoptics just seem downright classic for mini-sups in this region.

 

[Bill Schintler]

Chase target for Saturday, March 31

Chase target:
Waterloo, IA.

Timing:
Storm initiation: 4 PM CDT.

Mode:
Isolated supercells with a small tornado risk.

Synopsis:
UA analysis indicated impressive closed low, with the center of H85 low in NERN KS while the H5 low was centered over WCNTRL KS. An 80kt H5 max was surging through OK. Strong moisture advection was underway with an axis of 10C H85 dewpoints nosing into SCNTRL IA. At the surface, 15Z analysis indicated an elongated area of strengthening low-pressure over the MO river with a WF extending SE along a LRJ to OTM line. SFC dewpoints in SERN IA were being lifted NW along 10kt SFC flow. An EWRD-surging bulge in the CF was noted over SERN NE while visible satellite imagery indicated a developing clear slot in SWRN MO into IA where the CI shield was lifting NERD, revealing a broken mid-level cloud deck. Areas of precipitation were lifting rapidly to the N, primarily in NCNTRL IA.

Discussion:
The triple point of a WF and EWRD advancing CF should provide the focus for the redevelopment of storms by late afternoon where modest instability will couple with impressive shear parameters. A slot of clearing should allow for sufficient insolation to allow MLCAPE’s to reach 500J/kg, and this is supported by NAM, NGM, and RUC model soundings. Impressive shear parameters will overspread the area as a 70kt H5 speed max and a 40kt LLJ advance towards the area on top of backing SFC flow along and just NE of the WF. (SFC-6km) deep-layer shear of 60 kts will be coupled with good hodograph curvatures and LCL’s in the 700m AGL range as a narrow slot of 250m2/s2 (SFC-1km) SRH noses into the area.

- bill

 

[Brandon Sullivan]

we are en route for southwest of an ottumwa, to des moines line.. not spc 395 md..