Severe Storm Risk - Washita CPO, OK

There is a Enhanced 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 AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT ACROSS PARTS CENTRAL AND SOUTHWESTERN WISCONSIN...FAR SOUTHEASTERN MINNESOTA...EASTERN IOWA...MUCH OF NORTHERN AND CENTRAL ILLINOIS...NORTHERN AND CENTRAL MISSOURI...EASTERN AND SOUTHERN KANSAS...AND NORTHERN OKLAHOMA SUMMARY Widespread strong to severe thunderstorm development appears possible today into tonight across parts of the Upper Midwest southward across the lower Missouri Valley into central Great Plains. Initially this may be accompanied by a risk for large hail and a few strong tornadoes, before damaging wind gusts become the most prominent hazard by this evening. Discussion A couple of notable short wave perturbations have emerged from splitting larger-scale mid-level troughing now overspreading the northern Rockies and Great Basin. One, including a remnant embedded cyclonic circulation, is beginning to accelerate east-northeastward into and across the central Canadian/U.S. border vicinity. The other is still digging into the eastern Great Basin, but forecast to turn across the Wyoming/Colorado Rockies during the day, before shearing northeastward toward the Upper Midwest. It appears that this will be preceded by several lower amplitude impulses already emanating from the subtropical eastern Pacific. In lower-levels, a significant cold front is already surging southward to the lee of the northern Rockies and forecast to advance across much of the remainder of the northern Great Plains by 12Z this morning. Models indicate that significant cyclogenesis may subsequently ensue northwest/north of Lake Superior toward James Bay later today through tonight. At the same time, it appears that a secondary frontal wave will migrate northeast of the mid Missouri Valley through the Upper Midwest/Great Lakes vicinity. Another lee cyclone may attempt to form near/north of the Texas/Oklahoma Panhandle vicinity, but probably will be overtaken by the southward surging cold front before migrating out of the high plains. The northward advection of relatively moist low-level air is ongoing from the southern into central Great Plains and lower Missouri Valley, and forecast to continue spreading northward within a pre-cold frontal plume through portions of the Upper Midwest/Great Lakes region by this afternoon. Beneath steep lapse rates, this may contribute to sizable mixed-layer CAPE within a corridor from the east central Great Plains through the mid/upper Mississippi Valley by this afternoon. There is notable spread among the various model output concerning most of these developments, which may have a significant impact on the convective evolution and associated severe weather potential today through tonight. However, potential exists for widespread convective development capable of producing damaging surface gusts, large hail and a couple of strong tornadoes. Upper Mississippi Valley/Midwest vicinity It appears that a corridor of stronger surface pressure falls may shift from western Iowa north-northeastward through western Wisconsin by early this afternoon, accompanied by substantive boundary-layer destabilization and strengthening southerly low-level wind fields with enlarging hodographs. Based on the latest model output, including convection allowing guidance, it appears that this may contribute to a window of opportunity for discrete supercell development within an environment potentially conducive to strong tornadoes, before activity grows upscale and eventually outpaces the northeastward boundary-layer destabilization. Central Great Plains through middle Mississippi Valley/Midwest Uncertainty lingers concerning how quickly the surface cold front will tend to undercut a developing corridor of stronger pre-frontal surface heating and destabilization, particularly across the central into southern Great Plains. However, by early this afternoon, this corridor appears likely to develop along an axis from south central Kansas toward northwestern Missouri, providing a focus for rapidly developing storms including supercells. Initially this may include hail exceeding 2 inches in diameter, and potential for a few tornadoes before convection grows upscale, spreads east of the axis of maximum instability and also become undercut by the front. Perhaps aided by forcing associated with one of the perturbations emerging from lower latitudes, there appears a signal in model output that the upscale growing convection may eventually become better organized with one or two notable mesoscale convective vortices evolving while spreading ahead of the front across and northeast of the lower Missouri Valley late this afternoon and evening. Downward mixing of strengthening rear-inflow, within a sheared ambient southwesterly deep-layer mean flow already on the order of 35-40 kt, widespread strong to severe wind gusts appear possible, with strongest gusts and/or perhaps brief tornadoes accompanying evolving mesovortices along the gust front. The cold front/dryline intersection may become another focus for discrete supercell development across parts of south central Kansas into adjacent northwestern Oklahoma by late afternoon. However, the extent of the associated severe weather potential will depend on how quickly this activity is overtaken by the cold front.