Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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415 ACUS01 KWNS 041644 SWODY1 SPC AC 041642 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Sat May 04 2024 Valid 041630Z - 051200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WEST TEXAS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS CENTRAL AND NORTHWEST ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are expected across parts of the southern High Plains into the Hill Country of central Texas this afternoon and evening. Several storms may produce very large hail, and a couple strong tornadoes are possible. ...TX/southern OK/extreme southeastern NM... Not much change for this outlook update other than a minor southward shift of severe probabilities across far southeast NM and West TX to account for the projected cold front position by mid afternoon. Still expecting widely scattered to scattered thunderstorms to form this afternoon along and behind the cold front over west TX and southeastern NM, as well as ahead of the cold front, near the dryline and over strongly heated, relatively high elevations west of the Pecos Valley. The stronger updrafts will attain supercell characteristics and pose a large-hail threat on both sides of the front, with severe-wind and tornado potential more prevalent to its south. Forecast soundings south of the front indicate veering and increasing flow with height which will become very favorable for supercells. It still appears one or two dominant, prefrontal, mid/late-afternoon supercells may evolve and remain south of the front. The potential for a strong tornado in addition to giant hail will be the primary hazards with these warm sector supercells. Additional storm development is expected by early evening with an amassing of cold pools eventually expected, as southeasterly 850mb flow strengthens. A severe MCS will likely evolve during the evening and probably persist into the overnight as it moves east across portions of the Edwards Plateau and central TX. Have expanded wind probabilities farther east to account for a lingering threat for severe gusts and perhaps a localized risk for a tornado late as this activity moves east of I-35. ...North/northeast TX to mid Mississippi Valley/western Great Lakes vicinity... A diurnal intensification of isolated to scattered thunderstorms is expected this afternoon within this general corridor from the Red River Valley northeastward into the IL/WI vicinity. With much of this region located in between larger-scale mid-level waves, modest kinematic fields will tend to limit overall storm organization and severe potential. Nonetheless, heating of a moist boundary layer will facilitate the development of moderate instability by early to mid afternoon. Mainly semi-organized bands of multicells and clusters thereof will occasionally result in sporadic potential for wind damage and large hail. It appears perhaps a corridor for greater wind damage potential may occur immediately ahead/downstream of an MCV moving east across the mid MS Valley. Model guidance indicates slightly greater organized line segments and wind potential later this afternoon from central into northern portions of IL. Have also expanded the MRGL northward into portions of WI where sufficient destabilization will occur ahead of a front and associated mid-level disturbance over the Upper Midwest. ..Smith/Bentley.. 05/04/2024 $$