Web Version, PowerPoint Presentation

Development of the Synoptic, Thermodynamic and Shear Setting for the Tornadic Thunderstorm for Southwestern Kansas May 7, 2002

In order to identify the locales where tornadoes may be possible, the synoptic, thermodynamic and shear settings should be first evaluated. Synoptic conditions include the possibility of CVA east of a trough and deep and low-level shear conditions. In addition, the advection of warm, moist air in the lower levels (normally from the Gulf of Mexico) with sufficient CAPE can provide optimum buoyancy to induce upward motion and the development of convection.

Synoptic Conditions 500 mb Wind Observations, Heights and Temperatures	For the accompanying powerpoint presentation: micheledodgeppt.ppt.htm
	The 500 mb chart is used to approximate the deep layer shear (0-6 km) as 50 kt as the difference in the wind vectors between the surface (surface chart) and 500 mb. Significant storm development will be sustained in the presence of low level shear. Note, too, the ageostrophic nature of the 500 mb winds in central Kansas.
	Note the area in SW Kansas that just east of the trough in the Rockies. With ageostrophic winds in Central Kansas and significant favorable deep layer shear 50 kt or 5.0 E-3 /s (found in the 500 mb). Also the isodrosotherms indicate the advection of warm moist air into this same area.

Visible satellite images were also used to track the development of the supercell in SW Kansas
	Note the Presence of Cumuloform anvils in Southwest Kansas by 2145 on May 7, 2002
	Note the development and progression of cumulonibus anvils in Southwest Kansas by 2315 on May 7, 2002 had spread throughout Central Kansas.

Thermodynamics - When looking for the right thermodynamics for the formation of supercells, the presence of buoyant air is necessary. In the case of favorable shear, the CAPE doesn't necessarily have to be high.
	For the Topeka sounding at 00Z, take a look at the presence of CINH which makes this sounding a possible "loaded gun." Both the deep layer (> 69kt) and low level shear is favorable for supercells as are the helicity at 0-3 and 0-1 km, respectively. The hodograph suggests SREH in the lowest 0-1 km.
	For the Norman OK sounding at the same time, the CAPE is huge. Although there is significant the deep layer (> 69kt) shear, the low level shear is not as favorable as Topeka. Note that the helicity at 0-3 and 0-1 km, respectively is much lower than Topeka.

Look at the convection east of Dodge City at 6:37 on May 7, 2002.
Look at the hook that developed 30 minutes later at 7:37 PM on the county line.