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SPC Jun 10, 2024 1630 UTC Day 1 Convective Outlook

1 year 3 months ago

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Jun 10 2024 Valid 101630Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL HIGH PLAINS...SOUTHEAST GEORGIA/COASTAL SOUTH CAROLINA...AND WEST TEXAS... ...SUMMARY... Severe thunderstorms with large hail and severe wind gusts should occur across parts of the northern/central High Plains this afternoon and early evening. Other strong to severe thunderstorms may also occur across portions of the Southeast and southern Plains beginning this afternoon, where large hail and damaging winds will be possible. ...Northern/Central High Plains... A mid-level shortwave trough noted on water vapor satellite imagery over the northern Rockies will continue to advance eastward today over the northern High Plains. A related weak surface low over eastern MT should consolidate and shift into Saskatchewan through early afternoon, while a separate surface low develops over the central High Plains. A cold front is progged to move eastward through the afternoon and early evening over the northern High Plains. Low-level moisture will remain fairly limited ahead of the front, with surface dewpoints generally in the mid to upper 50s. But, steep mid-level lapse rates and daytime heating will aid in the development of weak to locally moderate instability in a narrow corridor by mid afternoon. Although mid-level flow is not expected to be overly strong, sufficient veering/strengthening of the flow with height through mid levels will still support generally 35-45 kt of deep-layer shear. Current expectations are for thunderstorms to develop along or just ahead of the front in the 18-20Z time frame. Initial supercells should pose a threat for mainly severe hail, but quick upscale growth into one or more small clusters will probably lead to a greater severe/damaging wind risk as convection moves quickly eastward. A tornado or two also appears possible. The relatively narrow warm sector suggests that thunderstorm intensity should decrease through the early evening with eastward extent across the northern/central High Plains. ...Southeast... Latest surface observations show a weak cold front situated across southern AL/GA into coastal SC. The presence of a moist low-level airmass and robust daytime heating along/south of this boundary will likely promote moderate to locally strong instability developing by early afternoon. Weak low-level convergence along the front, coupled with modest ascent on the southern fringe of an upper trough over the eastern CONUS, should support robust convective development by 18-20Z along/near the front in south/central GA and coastal SC. Weak westerly low-level flow is forecast to gradually increase with height through mid levels, which is expected to foster sufficient deep-layer shear to support supercells. Large hail should be a concern with this initially discrete activity, and some guidance shows potential for splitting supercells given a relatively long/straight westerly hodograph aloft. Occasional damaging winds will also be a concern with any small bowing clusters that can develop and spread eastward towards the coast through early evening. Weaker low-level convergence with southward extent into southern AL and the FL Panhandle suggests that overall thunderstorm coverage will remain more isolated across these areas. ...Southern Plains... A convectively augmented vorticity maximum/shortwave trough is evident late this morning over NM and west TX. An MCV is also noted in recent radar imagery across parts of northwest TX into the TX Panhandle. A surface cold front is in place over the southern High Plains. Although convective evolution remains somewhat uncertain later today, scattered thunderstorms will probably develop on the southern flank of the shortwave trough along and southwest of the front, and where better daytime heating can occur. Mid-level flow and related deep-layer shear should be a little stronger compared to yesterday, mainly owing to the influence of the MCV and mid-level shortwave trough. Latest high-resolution guidance continues to variability in whether an MCS will develop and become organized across west TX later today. Severe/damaging winds may occur if this scenario is realized, along with some hail with any isolated supercells that can develop. ..Gleason/Moore.. 06/10/2024 Read more