Severe Storm Risk - South Whitley, IN

There is a Marginal Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSISSIPPI VALLEY ACROSS THE TENNESSEE AND OHIO VALLEYS INTO THE MID-ATLANTIC SUMMARY Isolated to scattered severe thunderstorms are expected today from the ArkLaTex and Lower Mississippi Valley northeastward through the Ohio Valley and Mid-Atlantic. Synopsis Split-flow upper pattern persists across the CONUS this morning, with an upper low moving through TX in the southern stream and a shortwave trough moving through the northern and central Plains within the northern stream. Both of these systems are forecast to progress quickly eastward amid modest phasing and trend towards a more confluent, single-stream pattern by early tomorrow morning. Currently a broad region of moderate to strong low/mid-level flow extends from TX northeastward into eastern Ontario/southern Quebec. The strongest low-level flow with this broad region is over the Lower/Middle Ohio Valley, where 850 mb flow is around 50 to 60 kt. Thunderstorms are currently clustered over two areas within this broader region, IL and OH, and farther south from east TX into the Arklatex. The greatest severe thunderstorm potential is expected to concentrate downstream of the areas today, with damaging gusts as the primary severe hazards. Ohio Valley through the Mid-Atlantic Regional radar imagery shows a convective line extending from west-central IN southwestward into southern IL. This line is progressing quickly east-northeastward and has produced several strong gusts (i.e. 40-45 kt) thus far. Regional radar imagery also depicts a MCV moving into southern IL. Mesoscale ascent attendant to this MCV could be aiding in the development of the convective line as well as the more cellular storms to its south. General expectation is for this convective line to continue quickly northeastward across the Ohio Valley, with the robust low-level flow support in the potential strong to severe gusts as well as a few line-embedded tornadoes. This activity will spread east toward the Middle Atlantic by late afternoon. This ongoing line is well ahead of a shortwave trough moving through the northern/central Plains, and strong low-level moisture advection will likely result in airmass recovery in its wake ahead of the shortwave. As a result, a second round of thunderstorms is anticipated as the shortwave and its associated cold front moves through the Ohio Valley during the afternoon and evening. Despite airmass recovery, the overall buoyancy will likely be tempered by widespread clouds and muted diurnal heating. Even so, the combination of modest buoyancy with robust shear will still support another round of strong to severe thunderstorms. Strong gusts are the primary risk, but line-embedded tornadoes are possible as well. Any mature discrete development ahead of the front would likely be supercellular and capable of all severe hazards, including tornadoes. East Texas through the Southeast A few strong to severe thunderstorms are currently ongoing within a broad area of precipitation from east TX into southern AR, supported by modest buoyancy and strong vertical shear downstream of a shortwave moving through west TX. As mentioned in recently issued MCD 211, some weakening and veering of low-level flow has been noted in regional VWPs, but deep-layer shear remains favorable, and seasonably rich low-level moisture will continue to support moderate buoyancy. The severe threat may tend to remain rather isolated in the short term, though the strongest cells/clusters will be capable of producing locally damaging wind and perhaps a tornado. A more substantial increase in the coverage of the severe threat is expected later this afternoon, in response to increased ascent attendant to the approaching shortwave trough. This additional development will likely begin in a more cellular mode over east TX before progressing eastward and becoming more linear with time. All hazards are possible with this more cellular activity, including tornadoes. Southwesterly flow aloft should strengthen ahead of the shortwave throughout the evening and overnight, leading to increased organization and strength of the convective line. As such, the threat for damaging gusts and line-embedded tornadoes will persist throughout the night across the Gulf Coast states.