Severe Storm Risk - Florham Park, NJ

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 TODAY THROUGH TONIGHT ACROSS PARTS OF THE SOUTHERN GREAT LAKES INTO MID ATLANTIC AND PARTS OF THE NORTHERN GREAT PLAINS SUMMARY Scattered strong thunderstorm development is likely today through tonight, perhaps including a few organizing clusters, posing a risk for severe wind and hail across parts of the southern Great Lakes into Mid Atlantic and portions of the northern Great Plains into Upper Midwest. Discussion Large-scale mid-level troughing has overspread much of the Pacific coast through the Rockies. However, models indicate that further eastward progress will slow, as at least one significant embedded short wave trough digs offshore and contributes to amplification of the larger-scale trough near and offshore of the Pacific coast. As this occurs, downstream ridging is forecast to build across the northern Great Plains/middle Missouri Valley vicinity by late tonight, in the wake of a short wave trough now emerging from the Great Basin and forecast to progress north-northeast of the northern Rockies through the eastern Canadian Prairies and northwestern Ontario. Farther east, it appears that mid-level troughing and an embedded remnant low will slowly dig southeast of western Quebec/southern Ontario through the northern Atlantic Seaboard. A surface cold front accompanying the eastern Canadian perturbation is preceded by considerable ongoing thunderstorm activity overspreading the northern Mid Atlantic through Lake Erie vicinity. It appears that an outflow boundary associated with this convection may become quasi-stationary across parts of southeastern Pennsylvania/New Jersey, before the initially stalled upstream front, across southern portions of the Great Lakes vicinity into Upper Midwest, advances southeast of the lower Great Lakes through much of the northern Mid Atlantic and upper Ohio Valley by late tonight. Southern Great Lakes into northern Mid Atlantic The initially stalled composite outflow boundary and surface front appear likely to provide the focus for renewed thunderstorm development later today through tonight. Across the southeastern Wisconsin through southern Lower Michigan/northern Indiana and Ohio vicinity, it appears that the corridor of stronger destabilization along this boundary will remain in relatively close proximity to the southern fringe of the westerlies. East-southeastward into the northern Mid Atlantic this remains more unclear. Regardless, where the seasonably moist boundary layer becomes strongly heated, thermodynamic profiles a bit further aloft into mid-levels, aided by elevated mixed-layer air, will remain characterized by steep lapse rates of temperature and potential wet-bulb temperature. This will promote the risk for strong downbursts and evolving cold pools capable of producing strong to severe wind gusts in developing thunderstorm activity. There appears potential for one or two organizing clusters across and east-southeast of the southern Great Lakes region this afternoon into tonight. It is possible that severe wind probabilities could still be increased further, once forcing for convection and the potential negative impacts of early day convection become clearer. Northern Great Plains into Upper Midwest Forcing for ascent, near and downstream of the short wave emerging from the Great Basin, appears likely to overspread northern/eastern North Dakota into northwestern Minnesota during peak boundary-layer instability this afternoon and evening. Latest convection-allowing guidance suggests that this will provide support for intensifying thunderstorm development, which may include a few supercells in the leading warm advection regime, ahead of a possible upscale growing cluster near the crest of the building larger-scale mid-level ridging. Aided by pronounced veering of lower through mid-level wind fields, deep-layer shear appears conducive to the risk for large hail, in the presence of thermodynamic profiles with steep mid-level lapse rates and large CAPE in mid/upper levels. A few strong downbursts also appear possible.