Administrators NorthGeorgiaWX Posted July 9 Administrators Posted July 9 Day 4-8 Outlook Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Jul 09 2024 Valid 121200Z - 171200Z ...DISCUSSION... Deterministic and ensemble guidance offers a strong consensus on a general pattern shift involving deamplification of cyclonic flow over the Great Lakes, Ohio Valley and northeast on day 4 (12th-13th) through day 6 (14th-15th), but with a weaker version of the longwave trough lingering in that region through the remainder of the outlook period. Meanwhile, the Great Basin anticyclone is progged to expand and shift eastward toward the central Rockies day 4 through day 6, then deamplify over the central Plains. This process should reinforce an EML over the western plateaus and expand it eastward across the central Plains. As that occurs, west-northwesterly flow aloft should set up between the northern Plains and Great Lakes, mostly (but not entirely) north of a mean low-level frontal zone occupying a corridor from the north-central High Plains to the lower Missouri/Ohio Valleys. Strong lapse rates related to the EML, atop an enlarging area of upper 60s to mid 70s F surface dewpoints (from both advection and evapotranspiration), will yield a high-CAPE parameter space near the front. Provided it is not too far removed from that large buoyancy, the northeastern rim of the stronger EML capping, aligned parallel to the frontal instability gradient, may provide a favorable corridor for development/propagation of organized, severe-wind-producing MCS activity on at least one or two of those days, from the weekend into early next week. Activity may be supported by subtle shortwave troughs embedded in the largely front-parallel flow. Confidence in shortwave details, and in which day the cap is more likely to weaken enough to support suitable initiation and upscale growth, currently is too low to assign probabilities to a particular day in the series of somewhat similar ones, pattern-wise. Read more View the full article Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.