Severe Storm Risk - Orangeville, IL

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 SOUTHERN GREAT LAKES INTO THE MID-ATLANTIC STATES SUMMARY A couple of organized thunderstorm clusters are expected to develop across the southern Great Lakes and mid/upper Ohio Valley today through tonight, accompanied by the risk for damaging wind gusts. More widely scattered strong thunderstorms east of the Blue Ridge may also produce damaging wind gusts this afternoon and evening. Midwest/southern Great Lakes to Mid-Atlantic States As large-scale pattern amplification occurs, a belt of moderately strong northwesterly flow aloft will tend to overlie a frontal zone that extends from southern portions of Minnesota/Wisconsin east-southeastward to Pennsylvania/New Jersey. That said, ongoing convection has effectively modified/southward-shunted the effective front in several areas, and this will be the primary focus for storm intensification/redevelopment this afternoon, as well into the evening/late night. The steeper mid-level lapse rates will remain displaced west of the region, but ample low-level moisture (i.e. upper 60s/low 70s dewpoints) coupled with afternoon temperatures from the mid 80s to mid 90s will still support moderate to strong buoyancy near/south of the effective boundary. General storm re-intensification and/or new development is anticipated this afternoon, particularly south/ahead of currently ongoing clusters. Bowing line segments will be the predominant storm mode, with damaging winds as the most common hazard. The threat for damaging wind gusts will extend southeastward into the Mid-Atlantic this afternoon and evening amid a very warm and moist airmass. Vertical shear will be weaker with southward extent, but ample moisture (i.e. PW values from 1.8" to 2"), strong buoyancy, and steep low-level lapse rates will support the potential for strong outflow capable of wind damage. Bowing line segments will be the primary storm mode here as well. Southern Wisconsin/southern Lake Michigan vicinity The same general meteorological thematic scenario as described in the prior section applies to this region, and severe probabilities have been extended westward regionally, albeit for a somewhat conditional/uncertain scenario. A robust reservoir of moisture/locally extreme buoyancy will exist particularly to the south of ongoing midday convection. The region will be influenced by the amplifying upper ridge, but there is at least some possibility that storm redevelopment/intensification could occur near/east of the surface triple point and/or near outflow, with some related severe potential. Development could also occur toward the southern Lake Michigan vicinity later tonight as isentropic ascent increases near/northeast of the surface boundary. North-central Plains/Dakotas While perceived severe probabilities remain below 5%, some strong/sporadic severe potential may exist also South Dakota, far northern Nebraska and/or southeast North Dakota later today through late tonight, although confidence in specific meteorological scenarios remains low. Weak lee troughing will contribute to modest low-level convergence from western Kansas across western/central Nebraska into southwest South Dakota. Dewpoints will likely be in the low to mid 60s F within this convergence zone, and steep mid-level lapse rates will contribute to moderate/strong buoyancy. Even so, warm mid-levels may prevent the airmass from completely destabilizing. The remaining convective inhibition, coupled with the presence of large-scale height rises across the region, casts doubt to whether successful convective initiation will occur. Any mature updrafts could result in strong downdraft, but uncertainty remains high. Other storm development could occur tonight, potentially as a byproduct of a subtle mid-level wave/ongoing convection ongoing across South Dakota this morning.