The first of two potential severe weather outbreaks will likely occur during the afternoon and overnight hours of Saturday, March 11, 2006. Although not as ideal as Sunday, the conditions on Saturday still appear favorable for strong tornadoes over northern AR and southern MO. Our initial target area as of late on Friday night for Saturday is between Joplin and Springfield, MO. CAPE values of 2000+ J/kg, 0 CIN, strong upper flow, and 0-1km SR helicity values of 150 m2/s2 are forecast by the ETA and GFS to be centered near or to the south of SW Missouri between 18 and 00z. The ETA also forecasts convection developing by early- to mid-afternoon in central and eastern MO and southwest MO, northeast OK, and northwest AR by mid-late afternoon. A target of southwest MO was chosen because storms that develop to the south in northern AR and northeast OK would be easily accessible, as well as earlier storms in southwest/central MO. The ETA forecast 500 mb flow, 0-1km SR helicity, and CAPE at 00z, 00z, and 18z, respectively, are displayed below.

Major severe weather outbreaks are possible over the mid- to lower-Mississippi Valley on Saturday, March 11 and especially on Sunday, March 12. TV.net stormchasers Reed Timmer and Joel Taylor will of course be on-location during both of these potentially life-threatening events, attempting to capture extreme, close-up tornado footage. In response to a massive trough covering the entire western U.S., a strong low level jet developed on Friday afternoon and will continue throughout the weekend. As of 0600 UTC on 11 Mar 2006, low to mid 60oF have been transported as far north as southeast OK by the LLJ. By Saturday afternoon, at mid 60oF+ dewpoints will prevail as far north as central IL. Strong deep-layer shear, minimal linear forcing, and a deep-layer shear vector perpendicular to the boundary will likely yield discrete supercells throughout AR, MO, and IL on Saturday and Sunday. Low-level shear will be more than adequate for tornadoes on both Saturday and Sunday afternnoon/night over AR, MO, and IL, with at least 150 m2/s2 0-1 km SR helicities throughout the warm sector. Individual discussions for Saturday and Sunday follow below.

Stay tuned for updates!