Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
493 ACUS48 KWNS 130716 SWOD48 SPC AC 130714 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0214 AM CDT Thu Jun 13 2024 Valid 161200Z - 211200Z ...DISCUSSION... ...Day 5/Monday -- Eastern Dakotas/Minnesota... A southwesterly midlevel jet is forecast to overspread a seasonally moist/unstable environment on Monday. Large-scale ascent will remain somewhat nebulous as the more apparent synoptic upper trough remains over the northern Rockies. However, forecast guidance suggests a lead shortwave impulse may migrate through southwesterly mid/upper flow. Favorable vertical shear will support organized severe storms, though coverage and convective evolution remains uncertain. ...Days 6-8/Tue-Thu... Beyond Day 5/Monday, forecast guidance generally shows an overall slower trend with eastward progress of a western upper trough. Severe potential may increase across portions of the northern/central Plains around Day 6/Tue or Day 7/Wed if the trough ejects east/northeast. If this occurs, enhanced deep-layer southwesterly flow would overspread a seasonally moist and unstable environment ahead of a southeastward-advancing cold front. This overall pattern would support some severe potential somewhere from the northern into central Plains. The GFS suite of guidance is more progressive and favors this scenario. However, the ECMWF maintains a stronger eastern upper ridge with little eastward progression of the western upper trough through mid-week. Nevertheless, a broad area of enhanced deep-layer southwesterly flow will impinge on the northern Plains vicinity, and some severe potential seems probable, but location and timing is too uncertain to include probabilities. ..Leitman.. 06/13/2024