Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Wed Apr 26 2017 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM OKLAHOMA INTO THE LOWER TO MIDDLE MISSISSIPPI VALLEY AREAS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM A PORTION OF THE SOUTHERN PLAINS INTO THE TENNESSEE AND OHIO VALLEYS... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE SLIGHT RISK AREA... ...SUMMARY... Numerous severe storms remain possible on Friday from a portion of the southern Plains into the lower to middle Mississippi, Ohio and Tennessee Valleys. ...Southern Plains through the Tennessee and Ohio Valleys... Shortwave trough will shift northeast through the OH Valley early Friday with upstream height rises in wake of this feature from the southern Plains into the TN Valley. A warm front will develop northward and by early evening should extend from the southern OH valley into northern TX or southern OK with a dryline evolving across west-central into northwest TX where it will intersect the front. Limited synoptic forcing for ascent and capping due to eastward expansion of EML may limit thunderstorm initiation during the day over much of this region. Some chance for initiation will exist at the intersection of dryline and front over northwest TX by late afternoon. Large CAPE and strong vertical shear would favor a conditional risk for supercells with very large hail and a few tornadoes should such initiation occur. Rich low-level moisture with large CAPE will reside south of warm/Quasistationary front. The best chance for more widespread thunderstorm initiation will occur during the evening into the overnight from OK into northern AR, MO and into the TN and OH valleys along and north of the warm front as strengthening, broad low-level jet enhances convergence and isentropic ascent along and north of this boundary. Strong vertical shear profiles and instability will support organized storms including supercells with large hail and damaging wind the main threats, though a few tornadoes may also occur with surface-based storms developing closer to the warm front. ..Dial.. 04/26/2017Read more
from SPC Forecast Products http://ift.tt/GAMjPN
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