SPC AC 090659 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Jan 09 2020 Valid 101200Z - 111200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST OK...EASTERN TX...SOUTHERN AR INTO NORTHERN AND SOUTHWESTERN LA... ...SUMMARY... Severe thunderstorms are expected by midday Friday into early Saturday morning from eastern Oklahoma and Texas into the lower Mississippi Valley. Damaging wind gusts, tornadoes and isolated large hail are all possible, especially across parts of eastern Texas into Louisiana Friday afternoon into the overnight hours. ...Eastern OK/TX to the Lower MS Valley... Significant severe weather potential will exist from around midday Friday into early Saturday morning from portions of eastern OK/TX eastward toward the lower MS Valley vicinity. Multi-model consensus has trended a bit further west with initial development as the upper shortwave trough ejecting into the southern Plains intensifies and possibly develops a closed low. This will result in a surface low developing further west in the vicinity of the low rolling Plains of TX Friday morning, spreading east/northeast along the Red River during the afternoon and eastern AR by 12z Saturday. A cold front will extend south/southwest from the low from central OK toward Del Rio TX by 18z. Mid to upper 60s dewpoints will reside ahead of the front from southeast OK, eastern and coastal TX eastward into the lower MS Valley. A 50+ kt southerly low level jet will overspread the Arklatex by 18z and increasing upper forcing, frontal convergence and strong warm advection will result in convective development along the front near/just east of the I-35 corridor from central OK into north TX by midday. Most guidance has convection along the front quickly becoming linear given the intense boundary-parallel deep layer flow and strong forcing, this seems likely. However, steep midlevel lapse rates will exist from south TX toward the Red River. Any storm that can remain discrete initially could produce large hail in addition to tornadoes. Large hail potential will likely be confined in space and time in a narrow corridor from south-central OK into north TX. Ahead of the developing QLCS across portions of east TX, including the upper TX Coast vicinity, toward the Sabine River will be a warm sector capable of supporting more discrete supercell convection. This threat, while somewhat conditional, will be accompanied by a threat for a couple of strong tornadoes, damaging winds and hail. Currently, the ECMWF, RAP and GFS show temperatures 2-4 degrees warmer than the NAM, which should allow for somewhat greater destabilization, with MUCAPE values as high as 2000 J/kg indicated by the ECMWF. Furthermore, model guidance suggests a mostly rain-free warm sector through the morning hours until temperatures warm into the low 70s and the weak cap/EML erodes with the intensifying low level jet after 21z. The QLCS will track east/northeast across eastern OK/TX through the evening hours and southern MO/AR/LA overnight. How far east the line advances is a bit uncertain but should be in the vicinity of the MS river by the end of the period. Strong, damaging gusts and mesovortex tornadoes will accompany the QLCS. A lower risk for damaging gusts will extend northeast into central MO and southwestern IL given the intense low level winds, but lower dewpoints, meager instability and increasing CINH further north during the overnight hours should limit the threat. ...MAXIMUM RISK BY HAZARD... Tornado: 10% SIG - Enhanced Wind: 30% SIG - Enhanced Hail: 30% SIG - Enhanced ..Leitman.. 01/09/2020 CLICK TO GET WUUS02 PTSDY2 PRODUCT NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z