Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 04 2023 19:57:35 ACUS01 KWNS 041957 SWODY1 SPC AC 041956 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Tue Apr 04 2023 Valid 042000Z - 051200Z ....THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF IOWA...WESTERN ILLINOIS...FAR SOUTHEAST OKLAHOMA AND WESTERN ARKANSAS... ....SUMMARY... Tornadoes, severe thunderstorm gusts and large hail are likely today and tonight from the Upper Great Lakes to central Texas. Tornado potential is focused today over parts of Iowa/Illinois this afternoon, and especially tonight over parts of the Ozarks to the Arklatex region. ....Iowa and northern Missouri... The most substantial change for this update is a westward expansion of the higher tornado probabilities across parts of central/western IA and far northern MO. Recent hi-res guidance continues to suggest a corridor of convective initiation across northwest MO to western IA around 22 UTC, and this idea is supported by recent surface and satellite observations (see MCD #456 for additional short-term details). Elevated convection is also noted across north TX into southern OK. This activity is expected to intensify as it tracks northeast through the afternoon/evening into the higher risk probabilities (see forthcoming MCD #457 for additional details). ...Moore/Jewell.. 04/04/2023 ..PREV DISCUSSION... /ISSUED 1124 AM CDT Tue Apr 04 2023/ ....IA/IL/MO... A large upper trough is deepening over the Rockies today, with an 80-90 knot mid level speed max rotating across the Plains. The associated surface low will track from central KS into IA this afternoon while a warm front lifts northward across eastern IA and northern IL. This will result in a large unstable warm sector across parts of IA/IL/MO where forecast soundings show strong low-level shear profiles and ample CAPE for severe/supercell storms. This scenario is quite different than last Friday, with more concerns for capping in the warm sector and pockets of dry low-level air that reduces confidence in the number of storms and intense tornado potential. Nevertheless, scattered supercells are expected later today with very large hail, tornadoes, and damaging winds expected. Isolated strong tornadoes may occur. By mid-late afternoon, thunderstorms are expected to erupt near the surface low and along the trailing cold front over central IA/northern MO. Intense wind fields will be present in this area, along with strong linear forcing. Large hail and damaging winds are expected with this activity, along with the risk of supercell and/or QLCS tornadoes. ....ArkLaTex into southern MO/IL Tonight... By early evening, forecast soundings from most 12z guidance shows that a broad area of high conditional risk of tornadic supercells will develop from eastern OK into much of AR and southern MO. This area will still be somewhat capped and the mechanisms for convective initiation are uncertain. However, a consensus of guidance shows multiple clusters of supercells forming across this area and persisting through the evening. Wind fields will strengthen throughout the night and capping will weaken, leading to a serious concern for nocturnal tornadoes over the southern MDT risk area in MO/AR. Again, model guidance provides confidence in the risk of widely scattered supercells throughout the night across the area, although details of location and timing are uncertain. Strong or even violent tornadoes are possible in this scenario. $$ = = = 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) .