Severe Storm Risk - Nanty Glo, PA
Severe Storm Risk
-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 ACROSS PARTS OF THE EASTERN DAKOTAS AND WESTERN MINNESOTA AS WELL AS CENTRAL VIRGINIA INTO FAR NORTH-CENTRAL NORTH CAROLINA SUMMARY Widely scattered severe thunderstorms capable of large to very large hail and severe wind gusts appear possible across the eastern Dakotas and western Minnesota this afternoon and evening. Isolated to scattered damaging wind gusts will also be possible with the strongest storms in the southern Mid-Atlantic and Carolinas. Upper Mississippi Valley into north-central Nebraska Early-morning surface analysis reveals a low over far southwest Manitoba, with a cold front extending southwestward from this low into southeast MT and then westward across south-central MT. This surface low and associated cold front precede a well-defined shortwave trough currently moving through southern Saskatchewan. This shortwave is forecast to continue eastward today, with the attendant surface low and cold front progressing eastward as well. A warm and moist airmass will precede this cold front, with afternoon highs ranging from the upper 80s/low 90s across eastern SD/northwest MN into the upper 90s/low 100s from central SD into central NE. Boundary-layer mixing will be offset by modest low-level moisture advection, likely keeping dewpoints in the mid to upper 60s over much of the region. These warm and moist conditions will help destabilize the airmass, despite relatively warm mid-level temperatures at the base of a northeastward-advecting EML. Over 2000 J/kg of MLCAPE will likely be in place by the mid afternoon, with a pocket of 3000 J/kg possible across southeast SD by the late afternoon. Thunderstorm development is anticipated first across western ND and northwest MN as the cold front interacts with this buoyant airmass, with ascent along the front augmented by modest lift along the southern periphery of the shortwave trough. Enhanced mid-level flow will exist within the base of this shortwave as well, with the resulting combination of buoyancy and shear supportive of supercells early in the convective cycle, with large hail as the primary hazard. Some instances of hail in excess of two inches are possible. A somewhat quick transition to a more linear mode appears likely given the frontal forcing, close storm proximity, and likelihood of strong cold pools. Severe gusts will be the primary hazard once this upscale growth occurs. Lower storm coverage is anticipated with southward extent from central SD into northern NE. Here, weaker shear is expected to limit the potential for organized storm modes, though isolated occurrences of hail and severe wind gusts appear possible with the strongest storms. Mid-Atlantic into the Carolinas A hot and very moist boundary layer is forecast in the vicinity of a lee trough this afternoon, with MLCAPE generally from 1500-2500 J/kg. Forcing for ascent will be weak, with convergence along the lee trough as the primary impetus for convective initiation. Vertical shear will be weak, but scattered coverage and an outflow-dominant storm mode will support the potential for upscale growth into loosely organized clusters. Relatively high storm bases and steep low-level lapse rates will enhance downdraft potential with a risk for damaging wind gusts with the strongest storms. Highest coverage is expected from central VA into far north-central NC. Northern Great Basin into southern Montana and northern Wyoming Early-morning satellite imagery shows a shortwave trough moving into southwestern ID. This shortwave is forecast to continue northeastward across ID and western MT, moving within the northwestern periphery of an upper ridge centered over the Four Corners. Mid-level moisture and ascent associated with this shortwave will result in isolated to scattered thunderstorms across the region during the afternoon and evening. Moderate mid-level flow (i.e. 35-40 kt winds at 500 mb) will accompany this wave as well, resulting in sufficient deep-layer shear to support at least episodic supercell and bowing structures capable of damaging winds and isolated hail. Lower MS Valley A notable vorticity maximum is currently moving southward from southwest MO into northwest AR, with slow southward/southeastward progression of this vorticity maximum expected throughout the day. Ample low-level moisture exists over the region, supporting diurnal airmass destabilization and the development of strong buoyancy (i.e. MLCAPE from 2000 to 3000 J/kg) by the afternoon. Scattered to numerous thunderstorms are anticipated as the vorticity max moves through this environment. Vertical shear will be weak, limiting storm organization, but a few strong downdrafts are still possible. Isolated occurrences of marginally severe hail are possible as well.