Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu May 08 2025 08:58:45 ACUS48 KWNS 080858 SWOD48 SPC AC 080856 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CDT Thu May 08 2025 Valid 111200Z - 161200Z ....DISCUSSION... ....Southeast into Mid-Atlantic... By early next week, the cutoff upper low is forecast to become more progressive and move northeastward. As this occurs, convection will begin to overspread more of the Southeast into southern portions of Florida and eventually the Mid-Atlantic. At this time, the potential for several days of precipitation/cloud cover to impact surface heating does not suggest a substantive severe threat will exist. Furthermore, mid-level flow will weaken with time as the low lifts northeast. Moderate mid-level winds will remain over Florida until midweek. While Central/South Florida could see relatively higher severe potential on Tuesday into Wednesday, models still show limited destabilization on account of the uncertain surface heating described earlier. ....Northern Rockies/Plains... Strong upper-level winds will overspread the northern Rockies on Sunday. Mid-level ascent should be sufficient for potentially scattered storm development. Moisture still appears it may be limited, but some threat for severe wind gusts may accompany storms on Sunday in parts of southwest into central Montana. Uncertainty in storm intensity precludes highlights, however. As the trough continues to shift eastward, moisture return may be sufficient enough to support some potential for severe storms mid to late next week in parts of the Dakotas into Iowa/Minnesota. Aside from questions about low-level moisture, timing and structure of the trough varies in guidance and makes the coverage/intensity of storms too uncertain for highlights. ....Central/southern Plains... Model guidance continues to show the potential for a trough to impact these regions by mid/late next week. Timing and position of the stronger winds/greatest forcing continues to shift spatially, however. Given that both the GEFS/EPS ensembles show a trough in the mean next week does give some confidence in the general pattern. Available ML guidance has also picked up on the pattern shift and started to show an increased signal for severe potential. However, significant uncertainties remain. With the cutoff nature of the upper low in the lower Mississippi Valley, it is a feature that is not predictable in terms of how fast it will depart. If guidance is correct, it will move out right as the trough nears the Plains. This leaves little time for a deep moist layer to develop and move northward after a few days of offshore winds in the western Gulf. Low-level moisture forecasts ahead of the trough do show mid/upper 60s F dewpoints. That said, the moisture profile in the vertical is quite poor. It is not until next weekend that a signal for deeper moisture is evident in model guidance. Lastly, shortwave ridging will be in place ahead of the trough. Temperatures aloft do not appear likely to appreciably cool given the current forecast evolution of the trough and capping will be a concern. Trends in guidance will continue to be monitored. ...Wendt.. 05/08/2025 = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .