DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0701 PM CST SUN MAR 12 2006 VALID 130100Z - 131200Z ...THERE IS A HIGH RISK OF SVR TSTMS OVER EXTREME EASTERN KANSAS...MUCH OF MISSOURI...EXTREME SOUTHEAST IOWA AND WEST CENTRAL/NORTHWEST ILLINOIS... ...THERE IS A MDT RISK OF SVR TSTMS OVER EASTERN OKLAHOMA...FAR NORTHEAST TEXAS...ARKANSAS...AND SURROUNDING THE HIGH RISK AREA FROM EASTERN KANSAS TO WESTERN INDIANA... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK AREA FROM THE SERN PLAINS NEWD TO THE SRN GREAT LAKES/LOWER OH RIVER VALLEY... ...SIGNIFICANT SEVERE WEATHER OUTBREAK TO CONTINUE THROUGH TONIGHT... STRONG MID/UPPER LEVEL TROUGH...CURRENTLY LOCATED OVER THE CENTRAL HIGH PLAINS PER WATER VAPOR IMAGERY...WITH ASSOCIATED 100+ KT MID LEVEL SPEED MAX EXTENDING FROM ERN NM TO IA WILL CONTINUE TO TRANSLATE NEWD OVERNIGHT TOWARD THE UPPER MS VALLEY. STRONG HEIGHT FALLS WITH THIS TROUGH/WITHIN EXIT REGION OF JET WILL AID IN THE DEVELOPMENT OF A CLOSED LOW OVER MN BY 12Z MONDAY. SURFACE LOW...CURRENTLY LOCATED OVER NORTH CENTRAL-NERN KS...IS PROGGED TO TRACK/REDEVELOP ENEWD AND STRENGTHEN SOME REACHING NRN IL TO SRN LAKE MI BY 12Z MONDAY. WARM FRONT EXTENDING EWD WILL CONTINUE TO RETREAT NWD TOWARD THE SRN GREAT LAKES REGION...WHILE COLD FRONT TRAILING SWWD FROM THE SURFACE LOW SPREADS EWD OVERTAKING THE DRY LINE WHICH EXTENDED SWD FROM ERN KS TO CENTRAL OK/TX. COLD FRONT IS EXPECTED TO EXTEND FROM NRN IL THROUGH ERN MO TO NERN TX BY 12Z MONDAY. STRONG DEEP LAYER AND LOW-LEVEL SHEAR VALUES FORECAST TO PERSIST THROUGH THE EVENING/OVERNIGHT...COMBINED WITH MODERATE INSTABILITY SUPPORT A CONTINUED THREAT FOR LONG-LIVED SUPERCELLS ACROSS FAR ERN KS/SERN IA THROUGH MUCH OF MO/IL AND INTO WRN IND. TORNADIC SUPERCELLS ARE LIKELY...INCLUDING A THREAT FOR SEVERAL LONG TRACK STRONG-VIOLENT TORNADOES...ESPECIALLY WITHIN THE HIGH RISK AREA. VERY LARGE HAIL AND DAMAGING WINDS WILL ALSO BE A THREAT WITH ACTIVITY ACROSS THE MODERATE/HIGH RISK AREAS. LARGE SCALE ASCENT CONTINUING TO SPREAD ENEWD OVERNIGHT IS EXPECTED TO AID IN THE ADDITIONAL DEVELOPMENT OF STORMS SWD ALONG THE DRY LINE THROUGH ERN OK TO NERN TX THIS EVENING...WITH ACTIVITY SPREADING NEWD ACROSS AR/SRN MO TOWARD THE LOWER OH VALLEY OVERNIGHT. EFFECTIVE SRH VALUES RANGING FROM 150-300 M2/S2 SUGGEST POTENTIAL FOR TORNADIC SUPERCELLS...A FEW STRONG. IN ADDITION...LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THIS ACTIVITY. OVERNIGHT...CONVECTION IS EXPECTED TO CONSOLIDATE INTO ONE OR MORE BANDS OR CLUSTERS OF SEVERE STORMS ALONG/AHEAD OF THE ADVANCING COLD FRONT AS THEY MOVE EWD TOWARD THE MS VALLEY. ALTHOUGH THE SEVERE THREAT MAY TRANSITION TO PRIMARILY DAMAGING WINDS AND HAIL AFTER 06Z...THE STRENGTHENING LOW LEVEL JET AND RESULTANT INCREASE IN LOW LEVEL SHEAR/HELICITY SUGGESTS A CONTINUED THREAT FOR ISOLATED TORNADOES WITH BOWS OR EMBEDDED SUPERCELLS WITHIN QUASI-LINEAR SEGMENTS. ..PETERS.. 03/13/2006