000 ACUS01 KWNS 090602 SWODY1 SPC AC 090600 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Sep 09 2016 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CENTRAL PLAINS AND MID-MO VALLEY INTO THE OZARK PLATEAU... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN/CENTRAL PLAINS NORTHEASTWARD ACROSS THE LOWER OH VALLEY AND MID-MS VALLEY... ...SUMMARY... Areas of severe storms capable of damaging winds and some large hail are possible this afternoon and evening from the central Plains into the mid-MS Valley. More isolated activity is expected from the TX Panhandle into Ohio and southern Lower Michigan. ...SYNOPSIS... A midlevel shortwave trough initially over the northern Rockies will amplify across the central/northern Plains. An associated cold front will surge southeastward as a surface anticyclone builds over the central Rockies, and will extend from the upper MS Valley into the southern Plains by early Saturday morning. An antecedent moist and unstable pre-frontal air mass will support widespread thunderstorm development along the cold front during the afternoon and evening. Surface low pressure will deepen across WI into the Upper Peninsula of MI late in the period, while an associated warm front retreats northward to near Lake Huron. Elsewhere, a pair of midlevel anticyclones will meander across the Southeast and near the Four Corners, while a weak cutoff low drifts northward along the coast of southern CA. ...CENTRAL PLAINS ACROSS THE MID-MO VALLEY INTO WESTERN IA... Primary focus for thunderstorm initiation across the mid-MO Valley and central Plains will be along the aforementioned cold front, as midlevel height falls overspread the central Plains and mid-MS Valley in association with an amplifying shortwave trough. This area is also where confidence is highest in strong heating/destabilization occurring amidst low-mid 70s dewpoints within a plume of steepening midlevel lapse rates. A few supercells could occur with initial development with a primary threat of large hail and isolated damaging wind gusts from southern KS into western IA, and possibly a tornado. Convection should grow upscale into a south/southeastward moving MCS into OK/MO overnight before weakening late from TX into the mid-MS Valley. ...MO EASTWARD ACROSS SOUTHERN ILLINOIS AND INDIANA... Early morning thunderstorms are expected to be ongoing across parts of KS/MO within a weak warm air advection regime, but should diminish in coverage by late morning. Considerable spatial uncertainty exists regarding the position of an associated outflow boundary that is expected to be in place across MO, which may provide the focus for renewed thunderstorm development during the afternoon. However, deep-layer wind profiles will be favorable for a few clusters or supercells to develop near the outflow boundary, which could pose a threat for isolated strong to damaging winds and perhaps a tornado across southern/central MO into southern IL, with hail potential more limited by weak lapse rates aloft. More rapid return of low-level moisture should occur ahead of the approaching cold front late in association with a modestly strengthening low-level jet, and should support convection into the late evening and overnight across Indiana into southern lower MI. ..Rogers/Gleason.. 09/09/2016 $$