Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Dec 13 2022 00:39:26 ACUS01 KWNS 130039 SWODY1 SPC AC 130037 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 PM CST Mon Dec 12 2022 Valid 130100Z - 131200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS WESTERN KANSAS INTO NORTHWEST TEXAS AND WESTERN OKLAHOMA... ....SUMMARY... Severe thunderstorms are possible tonight across the high plains of western Kansas into northwest Texas and western Oklahoma. Some of these may become capable of producing hail and damaging wind gusts, along with potential for a couple of tornadoes. ....01Z Update... No substantive changes have been made to the outlook for tonight. Deep large-scale mid-level troughing encompassing much of the western U.S. continues to progress eastward, with an intense cyclonic mid/upper jet in its base nosing across areas near/north of the Southwestern international border through the Texas Panhandle vicinity. Strongest mid-level height falls currently along and to the north of this jet, across eastern Colorado through western New Mexico, are forecast to intensify through the night and become focused near a developing cyclone across the high plains of western Kansas into the Texas Panhandle by 12Z Tuesday. In the presence of strengthening low-level and deep-layer shear, the deepening lee surface trough has become the focus for modest low-level warming and moistening. This has contributed to weak boundary-layer instability, with the dryline a focus for thunderstorm initiation just east of the Colorado/Kansas state border vicinity into the northern Texas Panhandle. Beneath intensifying mid-level upward vertical motion, dynamic cooling will contribute to substantive further steepening of low/mid-level lapse rates through 03-06Z, which may support a narrow corridor of mixed-layer CAPE increasing in excess of 500 J/kg, and perhaps approaching 1000 J/kg (based on Rapid Refresh forecast soundings). This should provide an environment increasing conducive to supercells with the potential to produce marginally severe hail and a risk for tornadoes, before forcing along an eastward advancing cold front provides support for a developing squall line. As this occurs, the risk for damaging surface gusts will become the more prominent severe hazard for a period, before convection spreads eastward into an environment less supportive of appreciable boundary-layer destabilization. South of the more prominent mid-level cooling, across southwestern Oklahoma into northwest Texas, thunderstorms may form and intensify near/just ahead of the eastward advancing cold front late tonight. In the presence of more substantive low-level moisture return and intensifying lower/mid tropospheric wind fields (including in excess of 50 kt around 850 mb), low-level hodographs and thermodynamic profiles may become supportive convection capable of producing damaging wind gusts and a risk of tornadoes by daybreak. This may be aided by increasing forcing for ascent downstream of a short wave impulse now accelerating east-northeastward across Arizona. ...Kerr.. 12/13/2022 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .