Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
143 ACUS48 KWNS 180733 SWOD48 SPC AC 180732 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue Jun 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... For Friday/D4 into Saturday/D5, models indicate potential for a shortwave trough to move out of the western US and across the northern Plains and upper MS Valley. However, predictability is already low by this time, with little run-to-run consistency regarding the strength of the trough. While thunderstorms appear likely across the region during the time frame, the degree of severe potential remains in question. The ECMWF appears to be trending toward a stronger trough solution in recent runs. If this trough develops, it is expected to continue across the Great Lakes and Northeast for the Sunday/D6 to Monday/D7 period. Increasing flow fields with such a trough would likely result in increased severe potential, conditional on sufficient instability developing. Details aside, the primary message for the D4-8 period is a breakdown of the upper ridge in the East, with a somewhat progressive northern-stream storm track along the northern border states, with at least low-end severe areas likely in later outlooks as predictability increases. ..Jewell.. 06/18/2024