Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu May 04 2023 19:58:39 ACUS01 KWNS 041958 SWODY1 SPC AC 041957 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu May 04 2023 Valid 042000Z - 051200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST OKLAHOMA INTO CENTRAL TEXAS... ....SUMMARY... Isolated large hail, damaging gusts, and a couple of tornadoes will be possible this through this evening from southwest Oklahoma into northwest and central Texas. ....Synopsis... Only minor adjustments have been made to the Slight risk (Level 2 of 5) area across northwest TX/southwest OK. These changes are based on current position of the dryline and an outflow boundary, and trends in visible satellite/surface observations. Overall forecast thinking remains unchanged from the previous outlook. For short term severe potential across northwest TX and far southwest OK, see MCD 673 and Tornado Watch 185. For short term severe potential further south along the dryline across west-central TX, see MCD 674. ...Leitman.. 05/04/2023 ..PREV DISCUSSION... /ISSUED 1125 AM CDT Thu May 04 2023/ ....TX/OK area this afternoon/evening... Within the subtropical jet, embedded perturbations will eject east-northeastward from northern Mexico to the southern Plains through tonight. The strength and orientation of the midlevel flow supports modest lee cyclogenesis across extreme southeast CO, and resultant southerly low-level flow and moisture advection (mid-upper 60s dewpoints) across TX. A broad swath of mid-high clouds covers much of TX/OK this morning, with embedded/elevated convection ongoing in small clusters from the TX South Plains to southern/central OK. The cloud plume will slow surface heating in central/north TX, while the morning rainfall will tend to reinforce the baroclinic zone near the Red River through this afternoon. The stronger surface heating/mixing will occur with clearing of the mid-high clouds from the west by mid afternoon across west central into northwest TX. Low-level moisture advection will be rather modest (low 60s dewpoints) into the zone of stronger surface heating, with somewhat modest buoyancy expected by May standards in the southern Plains (MLCAPE around 1500 J/kg). Supercells will be most probable late this afternoon/evening where the warmer temperatures and steeper low-level lapse rates impinge on the northwest edge of the somewhat richer low-level moisture, near and east of the dryline/warm front intersection. Large hail (some of which be 2 inch diameter or a little larger) will be the main concern, though the stronger storms could produce isolated damaging winds. If a supercell can move along the baroclinic zone near or just south of the Red River this evening, the somewhat enhanced low-level shear and moisture will support the potential for a couple of tornadoes. Farther south, a few supercells will be possible from the Del Burros northeastward into the Edwards Plateau along the sharpening dryline by late afternoon. Relatively straight hodographs and MLCAPE near 2500 J/kg will favor large hail as the primary severe threat, some of which could be larger than 2 inches in diameter. ....Northern Rockies/Great Basin this afternoon/evening... Pockets of surface heating, and a band of ascent around the northeast periphery of the Great Basin midlevel low, will support scattered thunderstorms across the northern Rockies this afternoon/evening. Buoyancy and southeasterly deep-layer shear could be sufficient for a isolated storms with strong/damaging outflow gusts and marginally severe hail. $$ = = = 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) .