Subj : DAY2SVR: Enhanced Risk To : All From : Mike Powell Date : Mon Aug 07 2023 16:03:00 ACUS02 KWNS 071731 SWODY2 SPC AC 071730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Aug 07 2023 Valid 081200Z - 091200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS NORTHEAST COLORADO...SOUTHWEST NEBRASKA...AND FAR NORTHWEST KANSAS... ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL MISSISSIPPI EASTWARD INTO SOUTHERN GEORGIA... ....SUMMARY... Scattered severe thunderstorms are possible across portions of the central High Plains Tuesday afternoon into Tuesday night. Large to very large hail along with a risk for a tornado and widely scattered severe gusts will be the potential hazards. ....Synopsis... Water-vapor imagery midday Monday shows a potent mid-level shortwave trough over the Pacific Northwest. This feature is forecast to be over the northern Intermountain region Tuesday morning and move east-southeast through the central Rockies during the period. Farther east, a mid-level trough over the Lower Great Lakes southward into the Mid-Atlantic states will pivot eastward and be located to the east of the New England coast by late Tuesday night. At the surface, low pressure near Lake Ontario will shift northeast along the St. Lawrence Valley. A cold front attendant to the low will develop eastward across southern New England through the day and offshore the northeast Atlantic coast during the evening/overnight. The southern extent of the front will stall over South Carolina. Southerly low-level flow will maintain a very moist airmass from the central Plains into the Southeast. ....Central Plains... Large-scale ascent associated with the aforementioned disturbance will overspread the central High Plains by mid-late afternoon. Low-level upslope flow will maintain a moist airmass from northwest KS towards the Cheyenne Ridge and feature dewpoints ranging through the 50s and into the 60s over northwest KS/southwest NE. Steep 700-500 mb lapse rates near 8 C/km atop the moist boundary-layer will support MLCAPE around 2000-3000 J/kg. Elongated hodographs will favor supercells with the stronger updrafts through the early evening. The relatively moist conditions centered over northeast CO could yield a focus risk for a tornado during the early evening, in addition to the threat for large to very large hail (diameters 2 to 3 inches). A 30-kt southerly LLJ is forecast to develop during the evening/overnight with the terminus located within an 850-mb moist axis. Considered higher severe-wind probabilities adjoining to the east of the 30-percent severe hail probabilities but uncertainty remained high regarding the convective morphology/orientation of storms as the activity moves into north-central KS/southern NE. ....Southeast... Residual outflow from convection in the Day 1 period will likely reside from northern MS into central AL/GA. This will result in differential heating ahead of convection expected to be ongoing across eastern OK/AR Tuesday morning in response to a vorticity maximum migrating through northwesterly flow aloft. As this convectively enhanced vorticity max and related MCV shifts east by early afternoon, thunderstorm are expected to increase rapidly intensify from central MS east into AL during the early-mid afternoon. An organized cluster/MCS is forecast to spread east across central/southern AL/GA during the afternoon and reach southern GA by early evening. Very high PW (2+ inches) and around 4000 J/kg MLCAPE forecast downstream of the evolving thunderstorm complex will likely result in isolated severe gusts and at least widely scattered wind damage. ....Southern New England... Storms will likely be ongoing Tuesday morning in a warm advection band ahead of the surface cold front. Backed low-level winds and proximity to the surface low will result in 0-1 km SRH around than 250 s2/m2. Weak lapse rates will limit updraft intensity, but very moist low-levels coupled with the low-level shear will support an environment conditionally favorable for storm rotation. The severe threat will probably diminish by midday as the warm advection-related storms shift northeast and move into the adjacent Atlantic waters. ...Smith.. 08/07/2023 $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .